Search

Objective: The loss of the dental coronal portion following carious lesions or fractures leads to endodontic treatment with subsequent restoration to ensure correct anatomy and function. Recently, partial adhesive restorations have been widely proposed to increase the survival rate of endodontically treated teeth. The primary purpose of this review is to assess the failure rate of indirect partial adhesive restorations on endodontically treated teeth (ETT), considering the follow-up period. Methods: The indications reported in the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) were used to draft the present review. The study was constructed on PICO questions: population (patients who need indirect adhesive restorative treatment on endodontically treated teeth with onlay and overlay), intervention (onlay and overlay), control (patients with onlay and overlay on endodontically treated teeth) and outcome (failure rate and types of failure for onlay and overlay). The asked scientific question was: what are the failure rate and types of failure for adhesive indirect partial restorations on ETT? Results: The overall failure rate that emerges is 0.087 with a ratio of 121/1254, I2 80 % p-value< 0.001. Moreover, by meta-regression with covariates the follow-up period reports a coefficient of 0.013 with a P-value< 0.001. In conclusion, the indirect partial restorations on endodontically treated teeth displayed overall acceptable outcomes in terms of success from 2 to 4 years after their placement with only 4.32 % of failure. Failures increase after 7 years up to 12-30 years with failure rates of approximatively 10.65 % and 20.94 %. The analysis of the included articles reporting the causes of restorations failures showed that 15.51 % of cases were related to the loss of dental element. Significance: Besides the survival rates of indirect adhesive restorations on endodontically treated posterior teeth, it was highlighted that the majority of failures appeared restorable. Thus, partial restorations seemed able to prevent the ETT tooth loss.

The objective of this work was to evaluate the mechanical performance of Z350 resin composite modified with Bombyx mori cocoons silk nanoparticles for dental applications. Four experimental groups were analyzed G0% = Filtek Z350 resin composite (control); G1% = Filtek Z350 with 1% of silk nanoparticles; G3% = Filtek Z350 with 3% of silk nanoparticles; G5% = Filtek Z350 with 5% of silk nanoparticles. It was employed scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, 3-point flexural strength test, Knoop hardness test, and surface roughness. From 3-point flexural strength tests the control group presented the best results G0% = 113.33 MPa (±23.73). The higher flexural modulus was shown by groups G3% = 29.150 GPa (±5.191) and G5% = 34.101 GPa (±7.940), which are statistically similar. The Knoop microhardness test has shown statistical difference only among the G3% group between the top 80.78 (± 3.00) and bottom 68.80 (±3.62) and no difference between the groups. The roughness test presented no statistical difference between the groups. The incorporation of silk nanoparticles reduced the flexural strength of Z350 resin composite. The surface roughness and microhardness tests showed no changes in any of the groups studied. Resumo O objetivo deste trabalho foi avaliar o desempenho mecânico da resina composta Z350 modificada com nanopartículas de seda Bombyx mori cocoons para aplicações odontológicas. Quatro grupos experimentais foram analisados: G0%) Resina Z350 apenas (grupo controle); G1%) Reforço com 1% de nanopartículas de seda; G3%) Reforço com 3% de nanopartículas de seda; e G5%) Reforço com 5% de nanopartículas de seda. Foi empregado microscopia eletrônica de varredura, espectroscopia de energia dispersiva de raios X, difração de raios X, teste de resistência à flexão de 3 pontos, teste de dureza Knoop e rugosidade superficial. Nos testes de resistência à flexão de 3 pontos o grupo controle apresentou melhores resultados G0% = 0.113 GPa (±0.024). O maior módulo de flexão foi demonstrado pelos grupos G3% = 29.151GPa (±5.191) e G5% = 34.102 GPa (±7.94), que são estatisticamente semelhantes. O teste de microdureza Knoop mostrou diferença estatística apenas entre o grupo G3% entre os 80.78 superiores (± 3.00) e os 68.80 inferiores (±3.62). Não há diferença entre os grupos. O teste de rugosidade não apresentou diferença estatística entre os grupos. A incorporação de nanopartículas de seda reduziu a resistência à flexão da resina composta Z350. Os testes de rugosidade superficial e microdureza não apresentaram alterações em nenhum dos grupos estudados.

Background Antimicrobial photodynamic therapy (aPDT) has been used as adjunct treatment of deep caries lesions however the effects on the longevity of restorations are still limited. Aim to evaluate the performance of composite restorations in primary molars subjected to selective caries removal (SCR) associated with aPDT. Design randomized clinical trial was designed. Primary molars of patients (mean age 6.15 years) with deep carious lesions without signs and symptoms of pulp involvement were selected. A total of 64 teeth were randomly divided into groups G1 (SCR, 32 teeth) and G2 (SCR+ aPDT, 32 teeth) for treatment, restored with composite and evaluated after a week (T0 ), 6 months (T1 ), and 12 months (T2 ) according to the criteria of FDI. Groups were compare using the Rao-Scott chi-square test and logistic regression for complex designs to account for multiple observation subject (alpha = 0.05) RESULTS: Marginal adaptation for the SCR + aPDT group was significantly better in comparison to SCR group at T0 and T2 in Logistic Regression (T0: OR= 0.151; 95% CI = 0.03 - 0.068; p = 0.015. T2: OR= 0.201; 95% CI= 0.05 - 0.79; p = 0.022). Conclusion The marginal adaptation of primary molar resin restorations was positively affected by aPDT after 12 months of follow-up.

Cracked teeth frequently require protective adhesive restorations. This long-term, longitudinal retrospective clinical study aimed to evaluate the factors influencing the success and survival rates of cracked teeth with crack lines (CLs) in different directions when restored early with onlays or full-coverage crowns.The dental records of 71 patients with a total of 86 cracked teeth with different pulpal and periapical diagnoses and with follow-ups spanning over 1-11 years were included. Data regarding the demographics; clinical symptoms and signs; bruxism; occlusal interferences; eating habits; pulpal and periapical diagnoses; number, direction, location, and extent of CLs; probing depth; and coronary condition before and after the placement of definitive restorations were collected. Univariate associations between tooth survival and explanatory variables were assessed. The long-term survival rate was estimated using Kaplan-Meier analysis and the log-rank test. A multivariate analysis was performed using Cox regression analysis.The overall success rate was 93.0%, and the overall survival estimates of cracked teeth restored early were 98.6%, 94.9%, and 55.9% at the 1-, 5-, and 11-year follow-ups, respectively. The direction of the CLs did not influence the survival of the tooth. No significant association was observed between the type of tooth, probing depth, root canal treatment, and tooth loss (P .05). The multivariate analysis showed that previously treated cracked teeth (P .05), the provision of onlay restorations (P .05), and the placement of posts (P .05) had higher correlations with tooth loss. Additionally, the placement of full-coverage crowns resulted in lower tooth loss compared with the placement of onlays (P .05).Previous endodontic treatment in teeth that subsequently develop CLs has a negative impact on the survival rate of the teeth. Moreover, early placement of full-coverage crowns should be implemented for cracked teeth regardless of the direction or the number of CLs because it is associated with a higher cracked tooth survival rate.

The demands for dental materials continue to grow, driven by the desire to reach a better performance than currently achieved by the available materials. In the dental restorative ceramic field, the structures evolved from the metal-ceramic systems to highly translucent multilayered zirconia, aiming not only for tailored mechanical properties but also for the aesthetics to mimic natural teeth. Ceramics are widely used in prosthetic dentistry due to their attractive clinical properties, including high strength, biocompatibility, chemical stability, and a good combination of optical properties. Metal-ceramics type has always been the golden standard of dental reconstruction. However, this system lacks aesthetic aspects. For this reason, efforts are made to develop materials that met both the mechanical features necessary for the safe performance of the restoration as well as the aesthetic aspects, aiming for a beautiful smile. In this field, glass and high-strength core ceramics have been highly investigated for applications in dental restoration due to their excellent combination of mechanical properties and translucency. However, since these are recent materials when compared with the metal-ceramic system, many studies are still required to guarantee the quality and longevity of these systems. Therefore, a background on available dental materials properties is a starting point to provoke a discussion on the development of potential alternatives to rehabilitate lost hard and soft tissue structures with ceramic-based tooth and implant-supported reconstructions. This review aims to bring the most recent materials research of the two major categories of ceramic restorations: ceramic-metal system and all-ceramic restorations. The practical aspects are herein presented regarding the evolution and development of materials, technologies applications, strength, color, and aesthetics. A trend was observed to use high-strength core ceramics type due to their ability to be manufactured by CAD/CAM technology. In addition, the impacts of COVID-19 on the market of dental restorative ceramics are presented.

Background Repair increases the longevity of restorations and is well-accepted by patients. In this study, the authors assessed the acceptance of dental restoration repair by dentists and determined the main variables of repair versus replacement of defective restorations. Methods A 15-item questionnaire was developed and distributed electronically to the American Dental Association Clinical Evaluators panel members (n = 785) during a 2-week period in 2019. Descriptive, bivariate, and multivariable analyses were conducted. Results Of the 387 respondents, 83.7% stated that they repair defective restorations, and 16% stated that they always replace them. Reasons to forego a restoration repair among dentists who perform repairs included defect size and carious lesion extension (42%) and negative personal experience or lack of success (37.9%). However, the latter was considerably higher for dentists who do not perform repairs (60.7%). The most commonly cited patient-related reason and tooth condition to repair restorations were limited patient finances (67%) and noncarious marginal defects (86%), respectively. Neither sex nor age group was significantly associated with the practice of restoration repair (P = .925 and P = .369, respectively). However, sole proprietors were more likely to perform repairs than those in an employee, associate, or contractor practice setting (P = .008). The most significant reason to forego restoration was negative experience or lack of success (P = .002). Conclusions Restoration repair is considered a treatment option for managing defective restorations. Negative personal experience or lack of success and practice setting influenced the dentists’ decision to repair or replace a defective restoration. Practical Implications Understanding dentists’ clinical challenges and practice environment is necessary when advocating for this approach.

Background To analyze the potential cost savings in dental care associated with increased sugar-free gum (SFG) use among Chinese teenagers and adults. Methods The amount of SFG chewed per year and decayed, missing and filled teeth (DMFT) was collected from a cross-sectional survey to create a dose–response curve assumption. A cost analysis of dental restoration costs was carried out. A budget impact analysis was performed to model the decrease in DMFT and the subsequent cost savings for dental care. Three different scenarios for the increase in the number of SFG were calculated. Results The average cost savings per person in the Chinese population due to increasing SFG use ranged from 45.95 RMB (6.94 USD) per year to 67.41 RMB (10.19 USD) per year. It was estimated that 21.51–31.55 billion RMB (3.25–4.77 billion USD) could be saved annually if all SFG chewers among Chinese teenagers and adults chewed SFG regularly. Conclusion This study suggests that dental care costs could be significantly reduced if SFG use increased in the Chinese population.

Teeth that require endodontic treatment are often structurally compromised and this considerably complicates endodontic procedures. Therefore, pre-endodontic restoration is a key approach that dentists should consider for such teeth. This article discusses current concepts of pre-endodontic restoration, with a focus on adhesive restorative methods and surgical/orthodontic techniques, and provides a relevant decision-making flowchart., Key points Highlights the importance of pre-endodontic restoration for the predictability of endodontic treatment.Discusses restorability aspects for structurally compromised teeth.Reviews current restorative and surgical/orthodontic techniques for pre-endodontic restoration and provides a decision-making flowchart.

To investigate the influence of an intermediate layer of a flowable resin composite in class II resin composite restorations. The authors searched MEDLINE via PubMed, Scopus, LILACS, Embase, and Web of Science electronic databases, and the ClinicalTrials.gov website to identify laboratory and clinical studies that evaluated class II cavities with resin composite restorations with or without an intermediate layer of flowable resin composite. Two authors independently selected the studies, extracted the data, and assessed the risk of bias and the quality of the evidence. Meta-analyses were performed using RevMan5.3 with fixed-effects model comparing bond strength (MPa), fracture strength (Newton), and clinical (number of failures) outcomes between restorative techniques (with or without flowable resin composite as an intermediate layer). From 1707 potentially eligible studies, 140 in vitro studies and 14 clinical studies were selected for full-text analysis, and 11 were included in the systematic review, being 7 in vitro and 4 clinical studies. There was no statistically significant difference between the restorative techniques considering the outcomes evaluated. The heterogeneity found was null. The risk of bias was classified as medium for in vitro studies and unclear in most clinical studies. The quality of the evidence of the clinical studies was low. The use of flowable resin composite as an intermediate layer does not improve the effectiveness of the class II restorations based on laboratory and clinical outcomes. Flowable resin composite as an intermediate layer may be used for class II restorations; however, this technique does not improve the effectiveness of the class II restorations.

The aim of this study was to perform an integrative review on the layer thickness and microstructure of resin-matrix cements around custom-made or standard teeth root intracanal posts. An electronic search was conducted on the PubMed using a combination of the following scientific terms: intraradicular post, root intracanal post, resin cement, thickness, adaptation, endodontic post, layer thickness, fit, shape, and endodontic core. The literature selection criteria accepted articles published in the English language, up to May 2021, involving in vitro analyses, meta-analyses, randomized controlled trials, and prospective cohort studies. The search identified 154 studies, of which 24 were considered relevant to this study. The selected studies provided important data considering cement layer thickness, tooth preparation, endodontic post, and type of resin-matrix cement. The anatomical variability of root canal systems, such as the oval- or C-shaped, represents a challenge in dental restoration with tooth root intracanal posts. The fitting of intracanal posts to different root regions is variable resulting in thick and irregular layers of resin-matrix cement. Defects like pores, micro-cracks, and micro-gaps were detected in the resin-matrix cement microstructure and represent spots of stress concentration and fracture. Custom-made tooth root intracanal posts provide a proper fitting and decrease the layer thickness of resin-matrix cement. In fact, the layer thickness of resin-matrix cements depends on the fitting of endodontic posts to tooth root canals. An increase of resin cement thickness causes the appearance of defects like pores, micro-cracks, and micro-gaps that can induce stress concentration and fractures at interfaces. The fitting of the endodontic post into the teeth root canal determine the layer thickness of the resin-matrix cement to establish an adequate retention. However, the increase in the thickness of the resin-matrix cement layer can lead to a high number of defects like pores or cracks and therefore decrease the strength of the interface.

Objectives. The aim of this study was to explore the literature in order to assess systematically the association between amelogenesis imperfecta (AI) and caries development and to evaluate the DMF index among AI patients. Basic Research Design. PubMed was used to explore the database Medline. The key words used were “Amelogenesis Imperfecta” [Mesh], “Dental Caries” [Mesh], “Tooth Loss” [Mesh], “DMF Index” [Mesh], and “Dental Restoration, Permanent” [Mesh]. Moreover, an ad hoc search was performed in order to make the study as exhaustive as possible. Results. Fifty-five articles were retained. The total number of patients gathered was 499. A percentage of 68.8% of the articles dealt with cases with a relatively low dental caries process, 20.8% dealt with cases in which the dental caries process was relatively moderate, and 10.4% dealt with cases in which the dental caries process was severe. Teeth extraction due to dental caries was mentioned in 10 articles. Eleven articles, concerning 53 patients, mentioned dental fillings. Four patients did not have dental filling due to dental caries. DMF index was very low in 2 articles and low-to-high in 3 articles. Conclusion. Low dental caries susceptibility with AI patients was noticed in this study. A possible factor could be the lack of proximal contacts and elimination of fissures through enamel loss. The lack of dental caries susceptibility was also explained by the microbacterial specificity of hypoplastic AI patients. Moreover, it was also noted that the prevalence of dental caries among AI patients depends on sociodemographic change.

Background Glass ionomer cements (GIC) have been considered the top option to restore primary teeth by dentists. The most common supply forms are hand mixed and encapsulated GIC. There is a lack of information about the impact of different GIC supply forms on restoration survival. Methods This randomized clinical trial compared the survival rate of occlusal and occlusoproximal restorations in primary molars using two glass ionomer cements versions: hand-mixed (H/M) and encapsulated (ENC) after 24 months. Children aged 3–10 years who presented dentin caries lesions in primary molars were selected at School of Dentistry, University of São Paulo, Brazil. They were randomly assigned to groups: H /M (Fuji IX®, GC Europe) or ENC (Equia Fill®, GC Europe). The occurrence of restoration failure was evaluated by two blinded and calibrated examiners. The analyses were performed in Stata 13 (StataCorp, USA). To evaluate the primary outcome (restoration survival), we performed a survival analysis. Additionally an intention to treat (ITT) analysis were done at 24 months of follow-up. Cox Regression with shared frailty was performed to assess association between restoration failure and independent variables (α = 5%). Results A total of 324 restorations were performed in 145 children. The survival for H/M group was 58.2% and 60.1% for ENC, with no difference (p = 0.738). Occlusoproximal restorations had lower survival rate when compared to occlusal ones (HR = 3.83; p Conclusions The survival rate in primary molars is not influenced by the different supply forms of GIC. Also, occlusoproximal restorations present reduced performances when compared to occlusal cavities. Trial Registration This randomized clinical trial was registered on ClinicalTrials.Gov on 10/15/2014 under protocol (NCT 02274142).

Objective Fluoride (F)-releasing restoratives typically are either weak mechanically or release only low levels of F ions. The objectives of this study were to: (1) develop a novel photo-cured nanocomposite with strong mechanical properties and high levels of sustained F ion release via a two-step “co-precipitation + spray-drying” technique to synthesize CaF2 nanoparticles (nCaF2); and (2) investigate the effect of spray-drying treatment after co-precipitation of nCaF2 on mechanical properties and F ion release of composite. Methods Two types of CaF2 particles were synthesized: A co-precipitation method yielded CaF2cp; “co-precipitation + spray-drying” yielded nCaF2cpsd. Composites were fabricated with fillers of: (1) 0% CaF2 + 70% glass; (2) 10% CaF2cp + 60% glass; (3) 15% CaF2cp + 55% glass; (4) 20% CaF2cp + 50% glass; (5) 10% nCaF2cpsd + 60% glass; (6) 15% nCaF2cpsd + 55% glass; and (7) 20% nCaF2cpsd + 50% glass. A commercial F-releasing nanocomposite served as control. Results The nCaF2cpsd had much smaller particle size (median = 32 nm) and narrower distribution (22–57 nm) than CaF2cp (median = 5.25 μm, 162 nm–67 μm). The composite containing nCaF2cpsd had greater flowability, flexural strength, elastic modulus and hardness than CaF2cp composite and commercial control composite. At 84-day immersion in water, the nanocomposites containing 20% nCaF2cpsd had 65 times higher cumulative F release, and 77 times greater long-term F-release rate, than commercial control. Conclusions A novel two-step “co-precipitation + spray-drying” technique of synthesizing nCaF2 was developed. The photo-cured nanocomposite containing 20% nCaF2cpsd possessed strong mechanical properties and excellent long-term F-release ability, and hence is promising for dental restoration applications to inhibit secondary caries.

Objective To characterize and investigate efficacy of loading functionalized ZrO2 nanoparticles in 3-dimensional (3D) printed acrylate ester-based resin subjected to accelerated aging in artificial saliva. As well as to evaluate the effect of ZrO2 nanoparticle volume fraction addition on mechanical and physical properties of printed composite. Methods Functionalized ZrO2 nanoparticles were characterized using TEM and Raman spectroscopy. 3D printed dental resin was reinforced, with ZrO2 nanoparticles, in the concentration range (0–5 wt.%). The resulted nanocomposites, in term of structure and physical/mechanical properties were evaluated using different mechanical testing, microscopic and spectroscopic techniques. Results ZrO2 based nanocomposite was successful and formed composites were more ductile. Degree of conversion was significant at the highest level with blank resin and 1 wt.%. Sorption revealed reduction associated with volume fraction significant to neat resin, however solubility indicated neat and 4 wt.% had the lowest significant dissolution. Vickers represented critical positive correlation with filler content, while nanohardness and elasticity behaved symmetrically and had the maximum strength at 3 wt.% addition. In addition, 3 wt.% showed the highest fracture toughness and modulus. Improvement of flexural strength was significantly linked to filler concentration. Overall properties dramatically were enhanced after 3 months aging in artificial saliva, especially degree of conversion, microhardness, nanoindentation/elasticity, and flexural modulus. However, significant reduction was observed with flexural modulus and fracture toughness. Significance The outcomes suggest that the newly developed 3D printed nanocomposites modified with ZrO2 nanoparticle have the superior potential and efficacy as long-term provisional dental restoration materials.

Objectives The purpose of this in vitro reliability study was to determine the intra- and inter-examiner agreement of the revised FDI criteria including the categories “fracture of material and retention” (F1) and “caries at restoration margin” (B1). Materials and methods Forty-nine photographs of direct tooth-coloured posterior (n = 25) and anterior (n = 24) restorations with common deficiencies were included. Ten dental experts repeated the assessment in three blinded rounds. Later, the experts re-evaluated together all photographs and agreed on a reference standard. Statistical analysis included the calculation of Cohen’s (Cκ), Fleiss’ (Fκ), and weighted Kappa (wκ), the development of a logistic regression with a backward elimination model and Bland/Altman plots. Results Intra- and inter-examiner reliability exhibited mostly moderate to substantial Cκ, Fκ, and wκ values for posterior restorations (e.g. Intra: F1 Cκ = 0.57, wκ = 0.74; B1 Cκ = 0.57, wκ = 0.73/Inter F1 Fκ = 0.32, wκ = 0.53; B1 Fκ = 0.41, wκ = 0.64) and anterior restorations (e.g. Intra F1 Cκ = 0.63, wκ = 0.76; B1 Cκ = 0.48, wκ = 0.68/Inter F1 Fκ = 0.42, wκ = 0.57; B1 Fκ = 0.40, wκ = 0.51). Logistic regression analyses revealed significant differences between the evaluation rounds, examiners, categories, and tooth type. Both the intra- and inter-examiner reliability increased along with the evaluation rounds. The overall agreement was higher for anterior restorations compared to posterior restorations. Conclusions The overall reliability of the revised FDI criteria set was found to be moderate to substantial. Clinical relevance If properly trained, the revised FDI criteria set are a valid tool to evaluate direct and indirect restorations in a standardized way. However, training and calibration are needed to ensure reliable application.

We considered Class II dental cavities in critical tooth areas concerned with vital pulp therapy, and evaluated the marginal gap after treatment with Biodentine and Geristore, and one composite after either etching and adhesive (V2) and after use of a self-etching system (iBond Universal). We measured the surface morphology at the marginal gap by optical profilometry, and carried out analysis of the 3D data according to a new effective definition of marginal gap. The defined quantity was assessed for statistical significance of the apparent differences. The largest gaps appeared for Geristore (first) and Biodentine (not significantly lower), whereas the gaps of the composite controls were both lower, the lowest being the two-step self-etched system with respect to the three-steps etched and adhesive system, yet without statistical significance. Obviously, there is still room for improvement of the vital pulp therapy restorative materials, as compared to the use of standard composite systems.

Background In restorative dentistry, the use of high-speed air turbine, which generates aerosols, can be associated with the transmission of airborne diseases. New laser technologies could be useful in reducing the amount of aerosols, but there is a lack of scientific research on this topic. Material and methods This is a descriptive study to analyze the amount of aerosols produced after class I cavity preparation using high-speed air turbine (group 1) and Er,Cr:YSGG laser with two different parameters (groups 2 and 3). Fluorescein dye was incorporated into the coolant reservoir in order to visualize the production of aerosols during each procedure. Tooth preparation was performed in a typodont with human lower molar tooth under rubber dam isolation. The procedure was carried out in a transparent plastic box to avoid aerosols dispersion. Sixteen grade I cellulose filter discs were distributed along the surfaces of the box. The area contaminated with aerosols in the filters was measured using ultraviolet illumination. Results In group 1, the contaminated surface area covered with fluorescein dye reached 77.3% (1349 cm2) of the total; in group 2 (laser with 80% water) we observed 7.3% (128 cm2) and in group 3 (laser with 40% water) it was 3.8% (68 cm2). The reduction in water parameter from 80% to 40% coincided with 48% reduction of the contaminated area on the filter discs. Focusing on the surfaces of the box, we noted that the mean contamination on the left side was more than on the right side in all three experimental groups. In group 1 using air turbine, we measured a mean of 102.6[±7.5 SD]cm2 on the left side, compared to 70.6[±32.3 SD]cm2 on the right side. In laser groups 2 and 3, a mean of 12.8[±14.9 SD]cm2 and 6.8 [±5.7SD]cm2, respectively, was described on the left surface versus 0 cm2 of surface contamination on the right surface. Conclusions The contaminated area during the procedure of class I cavity preparation, is reduced by 70% using Er,Cr:YSGG laser compared to high-speed turbine. A slightly higher contamination was observed between laser groups with 80% versus 40% water. The use of Er,Cr:YSGG laser in restorative dentistry can be a valid treatment alternative to reduce aerosols production compared to conventional high-speed rotary instruments. Key words:Er,Cr:YSGG laser, Aerosols, SARS-CoV-2, Rotary instruments, conservative dentistry.

Objective Mechanical damages can occur from dental restoration processing and fitting, or while it is in-service. This study evaluates the damage sensitivity of translucent zirconia (5Y-PSZ) relative to conventional 3Y-PSZ following mouth-motion simulations at various loads. Methods 5Y-PSZ and 3Y-PSZ discs were adhesively bonded to a dentin-like substrate and divided into groups according to the load (50 N or 200 N) and number of cycles (up to 106) used in the chewing simulation. Specimens were mounted with 30° inclination in an electrodynamic mouth-motion simulator, and subjected to contact-slide-liftoff cyclic loading in water. Surface and sub-surface damages were analyzed using a sectioning technique. After the simulation, specimens were removed from the substrate and loaded with the damaged surface in tension for biaxial strength testing to assess their damage tolerance. Results The strength of both ceramics underwent significant degradation after mouth-motion simulations. For 5Y-PSZ, the strength degradation was greater (∼60%) and occurred at a lower number of cycles than 3Y-PSZ. Herringbone cracks emerged on 3Y-PSZ and 5Y-PSZ surfaces under a 200-N load after 50 and 10 cycles, respectively. Meanwhile at a 50-N load, cracks formed at ∼1000 cycles in both ceramics. Further increasing the number of cycles only had moderate effects on the strength of both ceramics, despite an increase in surface and sub-surface damage. More significantly, a 50-N occlusal load can debase the zirconia strengths as much as a 200-N load. Significance Surface flaws produced during the chewing simulation are capable of significant strength degradation in zirconia, even after a small number of low-load cycles.

Background Crown discoloration is an undesirable side effect of the use of triple antibiotic paste (TAP) in regenerative endodontic procedures (REPs). The aim of this ex vivo study was to assess the potential for tooth discoloration and induction of fluorescence associated with the use of TAP containing either doxycycline (DOX) or clindamycin (CLIN), and of calcium hydroxide (Ca(OH)2), by spectrophotometric analysis and confocal laser scanning microscopy (CLSM). Material and methods A total of forty single-rooted human teeth extracted by therapeutic indication were used. The root canals were enlarged using the step-back technique up to a K #80 file and were randomly divided into four experimental groups (10 specimens each): i)Ca(OH)2 group, ii)TAP with DOX group, iii) TAP with CLIN group, iv) Control group (no treatment). To quantify the change of color of the different groups of teeth included, the Vita Easyshade advance 4.0 spectrophotometer was used. CLSM was used to determine fluorescence. Results After 28 days of action inside the root canal, no extreme discoloration was visible, to the naked eye, in any of the teeth included in the study. Under the conditions of this ex vivo study, TAP with DOX induced the highest crown discoloration among the medicaments tested. In contrast, Ca(OH)2 and TAP with CLIN did not induce crown discoloration after 28 days. The TAP with DOX group presented the highest fluorescence measurements. Conclusions Considering the discoloration potential and fluorescence changes in TAP with DOX or other tetracyclines, and the cytotoxic effect of TAPs, we recommend the use of Ca(OH)2 for REPs. Key words:Discoloration, doxycycline, clinadamycin, calcium hydroxide, endodontics.

Background Glass ionomer cements (GIC) used for restoration of missing dental structures have high biocompatibility and remineralization potential. However, low mechanical resistance excludes their use for long-term restorations of extensive lesions, particularly on approximal surfaces in permanent dentition. GIC with increased viscosity have much better physical properties, which involves better bonding and wear resistance, so they can be considered as an alternative to composite resin materials. The aim of this study was to perform a clinical and radiological assessment of restorations in permanent teeth, made with an increased viscosity GIC - Equia Fil (Ivoclar Vivadent) with Equia Coat (Ivoclar Vivadent) and composite material - Tetric EvoCeram (Ivoclar Vivadent) in young patients. Material and methods A total of 100 cavities on approximal surfaces were filled with the composite material or GIC in 49 patients aged from 12.08 to 19.58 years. During control examinations, the condition of each restoration was assessed with criteria acc. to Hickel et al. Bitewing radiographs had been taken before fillings were placed and after 12 and 24 months. Results After two years of observations, two GIC restorations were replaced due to loss of retention and staining. The other 96 restorations were given a satisfactory grade. The clinical efficacy of Equia Fil after 24 months was assessed at 95.83%, the Tetric EvoCeram at 100%. The difference was not statistically significant (P=0.145). When GIC was used, there was a higher risk of marginal adaptation deterioration and the occurrence of staining and erosion. Radiographic efficacy of the Equia Fil material for cavity restoration after 24 months was assessed at 93.75%, for the Tetric EvoCeram material at 100%. Differences were not significant statistically (P=0.073). Conclusions Tetric EvoCeram and Equia Fil used for the restoration of approximal lesions in premolars and permanent molars have similar efficacy in a 2-year period of observation. Key words:Dental restoration, permanent, composite resins, glass ionomer cements, clinical study.

PURPOSE To measure the chemical composition, Knoop hardness, surface roughness, and composite bond strength of additive manufactured (AM) and conventional interim materials. MATERIAL AND METHODS Disks were prepared using conventionally (CNV group) and additively manufactured (AM group) materials: CNV-1 (Protemp 4; 3M ESPE), CNV-2 (Anaxdent new outline dentin; Anaxdent), AM-1 (FreePrint temp; Detax), AM-2 (E-Dent 400 CB Envisiontec), AM-3 (NextDent CB 3D Systems), and AM-4 (Med620 VEROGlaze; Stratasys). Each group was subdivided into 3 subgroups (n = 20) for analyzing Knoop hardness (KHN), chemical composition, superficial roughness (Ra), and composite shear bond strength. The first subgroup was exposed to a microhardness test. Subsequently, EDAX analysis was selected to analyze the chemical composition. The second subgroup was selected to measure the superficial roughness (Ra) using a contact profilometer. The third subgroup was used to measured composite shear bond strength using a universal testing apparatus. A digital microscope was used to analyze the fracture mode. The Shapiro-Wilk test showed normally distributed data. One-way ANOVA and post hoc Sidak tests were selected (α = 0.05). RESULTS Major variances in chemical composition were observed among the specimens. Significant differences in Knoop hardness (p < 0.001) and surface roughness (p < 0.001) were detected. The AM-4 (13.45 ± 2.93 KHN), the CNV-2 (13.35 ± 5.84 KHN), the AM-2 (13.03 ± 3.29 KHN), and the AM-1 (12.55 ± 2.93 KHN) groups obtained the highest Knoop hardness values, followed by the AM-3 and the CNV-1 groups (p < 0.05). The AM-1 group (1.88 ± 1.11 Ra) obtained the highest surface roughness values among the groups, followed by the AM-3 group (0.90 ± 0.14 Ra) (p < 0.05). However, no significant differences in shear bond strength values were found between the groups ranging from 23.18 ± 8.88 MPa to 33.29 ± 9.17 MPa (p = 0.061). All the groups showed a cohesive mode of failure. CONCLUSIONS The AM interim materials tested had significant chemical composition variations compared to conventional materials. For the mechanical properties evaluated, the AM materials obtained appropriate mechanical properties for use as an interim dental restoration. However, further studies are required to evaluate more extensively its mechanical properties and verify their applicability in the oral cavity, clinical behavior, and biocompatibility.

Silicon nitride (Si3N4) is one of the promising ceramics for dental restoration due to providing significant benefits during the application. This study aimed to investigate the potential use of Si3N4 for all-ceramic dental restorations by characterizing some critical properties as color shade, mechanical resistance, shear-bond strength and radiolucency. For our study, porous Si3N4 ceramic was produced by partial sintering process with limited amounts of sintering additives and low temperature. A commercial ZrO2 ceramic was prepared according to manufacturer’s instructions and results were compared with Si3N4. Si3N4 is an attractive ceramic for dental applications with good mechanical properties even in porous form, it has additional advantages over the conventional ceramics used as restorative material, such as, inherent antibacterial/anti-infective activity, radiolucency, and lower hardness. It is expected that Si3N4 will become popular in dental applications as well. WOS:000640288300023 PMID: 33028788 Q3 Q4

espanolIntroduccion: Dos factores importantes en la protesis dental son hacer una impresion precisa y la produccion de un modelo adecuado que represente la relacion exacta entre el diente preparado y las estructuras orales. Este estudio, tuvo como objetivo investigar los efectos de diferentes combinaciones de materiales de impresion y vertido sobre la adaptacion marginal e interna de coronas de zirconio premolar. Material y Metodos: Se prepararon cuarenta premolares maxilares considerando la linea de meta del hombro redondo. Las impresiones se realizaron con silicio adicional (Panasil) o de condensacion (Speedex) y se vertieron con dos tipos diferentes de materiales de yeso (yeso Siladent o GC) (N = 10). Las coronas de zirconio se fabricaron utilizando el sistema CAD-CAM. Las coronas se cementaron y las muestras se cortaron en direccion buco-lingual. La brecha marginal e interna se midio con estereomicroscopio (×25). Resultados: Las brechas marginales medias para Pansil-Siladent, Panasil-GC, Speedex-Siladent y Speedex-GC fueron de 141μm, 143μm, 131μm y 137μm, respectivamente. Las brechas internas fueron 334μm, 292μm, 278μm y 257μm, respectivamente. La prueba de T-Student independiente no mostro diferencias significativas en la brecha marginal o interna promedio entre varios materiales de impresion y yeso o sus interacciones (p>0.05). La prueba ANOVA bidireccional no mostro diferencias significativas en el espacio marginal o interno maximo entre varios materiales de yeso y de impresion y sus interacciones (p>0.05). Conclusion: El presente estudio no revelo diferencias estadisticamente significativas en la brecha marginal/interna entre las coronas preparadas con diferentes combinaciones de materiales de impresion y vertido evaluados. EnglishPurpose: Two important factors in dental prosthesis are making an accurate impression and producing a suitable cast which represents the exact relationship between prepared tooth and oral structures. This study, aimed to investigate the effects of different combinations of impression and pouring materials on marginal and internal adaptation of premolar zirconia crowns. Material and Methods: Forty maxillary premolars were prepared considering round shoulder finish line. The impressions were made either by additional (Panasil) or condensation (Speedex) silicon, and poured by two different types of gypsum materials (Siladent or GC gypsum) (N=10). Zirconia crowns were fabricated using a CAD-CAM system. The crowns were cemented, and the samples were cut in bucco-lingual direction. Marginal and internal gaps were measured by stereomicroscope (×25). Results: The mean marginal gaps for Pansil-Siladent, Panasil-GC, Speedex-Siladent, and Speedex-GC were 141 μm, 143 μm, 131 μm, and 137 μm respectively. The internal gaps were 334 μm, 292 μm, 278 μm, and 257 μm respectively. The independent T-Student test showed no significant differences in average marginal or internal gap among various impression and gypsum materials or their interactions (p>0.05). Two-way ANOVA test showed no significant differences in maximum marginal or internal gap among various impression and gypsum materials and their interactions (p>0.05). Conclusion: The present study revealed no statistically significant difference in marginal/internal gap among crowns prepared using different combinations of impression-pouring materials evaluated.

Background/purpose: Composite resin is currently the most widely used dental restoration material. Previous studies have demonstrated that the application of Chlorhexidine (CHX) on the dentin surface after acid etching can result in an improvement in the integrity and stability of tooth restoration through time. In order to better understand whether CHX can help improve the stability of the resin-dentin bond strength, in this study, a comprehensive review of the effect of adding CHX to the adhesive system on the stability of immediate and long-term resin-dentin bond strength was conducted. Materials and methods: This article was written in accordance with the PRISMA Statement and is registered on the International Prospective Register of Systematic Reviews (registration number CRD42018084962). Six electronic databases including PubMed, Embase, Cochrane library, ISI Web of Science, ClinicalTrials.gov and China National Knowledge Infrastructure (CNKI) were searched up to October, 2018. Ten articles were selected from 340 possible eligible articles for meta-analysis, and 41 sets of data were analyzed in the meta-analysis. Results: The results indicated that the use of 0.1% and 0.2% CHX does not adversely affect the immediate bond strength (p > 0.05), but both 0.1% and 0.2% CHX increased bond strength compared with the control group over 12 months (p

Background and Overview Molar-incisor hypomineralization (MIH) is a qualitative developmental defect of enamel, which has been a daily concern in clinical practice owing to its difficult treatment. Case Description An 11-year-old girl was admitted to the pediatric dental clinic with a symptom of severe hypersensitivity in the permanent molars owing to MIH. The treatment consisted of a simplified occlusal replica adapted technique with conventional glass ionomer cement in the MIH-affected molars, which involved laboratory and clinical stages. The patient was reexamined every 3 months, and after 18 months there was no additional tooth structure loss, restoration failure, or pain. This technique may be considered a feasible alternative to restore hypomineralized teeth owing to its reduced procedure time and good performance in the follow-up period of 18 months. Conclusions and Practical Implications The technique successfully restored the function and shape of the affected teeth, decreasing the sensitivity by means of covering the demarcated MIH opacities.

The purpose of this in vitro study was to investigate the effects of different air-abrasion pressures on flexural strength and shear bond strength of a translucent zirconia. The translucent zirconia surface was treated with 50 μm abrasive alumina particles at different pressure: 0.1 MPa; 0.2 MPa; 0.3 MPa; 0.4 MPa; 0.5 MPa; untreated specimens were used as control group (n = 33). For each group, three-point bending test was used to evaluate the flexural strength, and surface characterizations were analyzed. Following adhesive bonding and water storage for 24 h, specimens were subdivided into groups baseline and aged (5000 thermocycles). Then, shear bond strength was measured and failure mode was recorded. Statistical analysis was performed with one-way ANOVA and Tukey test (α = 0.05). Increasing air-abrasion pressure (0.3 MPa, 0.4 MPa, and 0.5 MPa) decreased the flexural strength. Higher air-abrasion pressure resulted in rougher zirconia surfaces and caused more microcracks. The highest shear bond strength was obtained for zirconia surfaces abraded at 0.2 MPa (15.88 ± 2.70 MPa) and 0.3 MPa (14.32 ± 1.12 MPa). Aging did not decrease the strength for all groups except control group (p < 0.001). Air-abrasion with 50 μm abrasive alumina particles at 0.2 MPa could achieve good strength for translucent zirconia ceramics while maintaining adequate and durable bonding with resin cement. A total of 0.2 MPa is recommended for air-abrasion procedure applied before a dental restoration fabricated with translucent zirconia is bonded to resin cement.

Clinical Relevance Restoring Class V cavities with a regular bulk-fill composite presents a more favorable biomechanical behavior than restoring with a regular nano-filled composite. SUMMARY Purpose: This study evaluated the influence of Class V cavity extension and restorative material on the marginal gap formation, before and after aging, and the theoretical polymerization shrinkage stress distribution in a tooth restoration. Methods and Materials: Class V cavities with the depth of 2 mm, cervical/incisal distance of 4 mm, and margins located in the enamel 1 mm above the cementoenamel junction were prepared in 60 bovine incisors in two mesiodistal dimensions (n=30): 2.9-mm large extension cavities (LE) or 1.4-mm small extension cavities (SE). The cavities' depths were validated using a periodontal probe, while the mesiodistal and cervical/incisal distances were measured using a stereomicroscope. After adhesive application (Clearfil SE Bond), each group was randomly divided into two groups (n=15) according to the restorative material: Filtek Z350 XT (N) or Filtek Bulk Fill Posterior (BF). The marginal gap formation between the tooth structure and the restorative material was evaluated using a stereomicroscope before and after thermocycling for 15,000 cycles (5°C and 55°C). Data were analyzed using repeated-measures analysis of variance (ANOVA) and Tukey test for multiple comparisons (α=0.05). A three-dimensional geometric model with the same dimensions as the experimental test was created for each cavity, and the restorations were modeled for each restorative material. In the analysis software, the finite element mesh was created with tetrahedral quadratic elements, and the polymerization shrinkage was simulated by thermal analogy. The maximum principal stress was used to express the tensile stress in the adhesive interface through colorimetric graphs. Results: For the marginal gap, the repeated-measures ANOVA revealed a significant effect only for the factors composite resin (df=1, F=4.09, p=0.04) and thermal aging (df=1, F=44.35, p SE-N (15.0 MPa) > LE-BF (9.1 MPa) > SE-BF (8.2 MPa). Conclusion: Marginal gaps in the specimens fell between approximately 12 and 17 μm; however, the regular bulk-fill composite showed less gap formation and better stress distribution around the cavity margin than the regular nano-filled composite, regardless of the cavity extension.

Objective The aim of this in vitro study was to test the effect of different composite modulation protocols (pre-heating, light-curing time and oligomer addition) for bulk filling techniques on resin polymerization stress, intra-pulpal temperature change and degree of conversion. Methods Class I cavities (4 mm depth × 5 mm diameter) were prepared in 48 extracted third molars and divided in 6 groups. Restorations were completed with a single increment, according to the following groups: (1) Filtek Z250XT (room temperature – activated for 20 s); (2) Filtek Z250XT (at room temperature – activated for 40 s); (3) Filtek Z250XT (pre-heated at 68 °C – activated for 20 s); (4) Filtek Z250XT (pre-heated at 68 °C – activated for 40 s); (5) Filtek BulkFill (at room temperature – activated for 20 s); (6) Filtek Z250XT (modified by the addition of a thio-urethane oligomer at room temperature – activated for 40 s). Acoustic emission test was used as a real-time polymerization stress (PS) assessment. The intra-pulpal temperature change was recorded with a thermocouple and bottom/top degree of conversion (DC) measured by Raman spectroscopy. Data were analyzed with one-way ANOVA/Tukey's test (α = 5%). Results Pre-heating the resin composite did not influence the intra-pulpal temperature (p = 0.077). The thio-urethane-containing composite exhibited significantly less PS, due to a lower number of acoustic events. Groups with pre-heated composites did not result in significantly different PS. Filtek BulkFill and the thio-urethane experimental composite presented significantly higher DC. Significance Resin composite pre-heating was not able to reduce polymerization stress in direct restorations. However, thio-urethane addition to a resin composite could reduce the polymerization stress while improving the DC.

Clinical Relevance It is possible to modify the natural emergence profile of the tooth using simple intrasulcular direct restorations. The shape of the intrasulcular part of the restoration will determine the design of the gingival contour. SUMMARY Some clinical situations, such as the closure of pronounced diastemas and the transformation of malformed, small, or peg-shaped teeth, require a rebalancing of dental proportions accompanied by a modification of the gingival contour. A traditional treatment plan might require surgical, prosthetic, and/or orthodontic treatment, but in some cases, these therapeutic options could be considered too invasive and not always the best solution. Moreover, not all patients are ready to undergo irreversible, long, and expensive procedures. To overcome these limitations and to solve all of these clinical problems in a rapid and noninvasive way, we propose a new technique that allows us to modify the natural emergence profile of the tooth using simple intrasulcular direct restorations. Using the Biologically Active Intrasulcular Restoration technique, it is possible to rebalance tooth shape and dimensions, gingival level and contour with low biological and economic costs. This method, which does not require any preparation of the dental tissues, is reversible and minimally invasive. It is applicable to patients of all ages, and results are obtained in a single appointment.

SUMMARY Background and Objectives: Information on the choice of material and performance of restorations placed in a dental practice annually is limited. The Minamata Convention on Mercury is likely to affect the use of amalgam worldwide. The objective of this research was to investigate the use of restorative materials at the University of Otago Faculty of Dentistry in New Zealand from 1998 to 2017. Methods: Data from the Faculty of Dentistry's database from the years of interest were compiled. These data included information on the characteristics of restorations, including information on the material used and number of surfaces involved for each restoration. The tooth in which each restoration was placed was categorized by arch, tooth type, and deciduous or permanent dentition. Results: Records identified 227,514 permanent restorations placed from January 1998 to December 2017, of which 91.7% were direct restorations. Among direct restorations, composite resin was the most commonly used material, followed by amalgam, glass ionomer, and compomer. The use of amalgam for direct restorations decreased from 52.3% of direct restorations in 1998 to 7.1% in 2017. A corresponding increase was observed in the use of tooth-colored direct restorations, particularly composites. Among indirect restorations, porcelain fused to metal, gold, and stainless steel (in pediatric applications) were the materials most frequently used. Conclusions: Despite having no official policy on reducing the use of dental amalgam, the Faculty of Dentistry is following the global trend in reducing its use, with composite resin now well established as the predominant restorative material used. If the current rate of decline persists unchecked, the Faculty of Dentistry could transition to being amalgam free by 2020, although it seems likely that the characteristics and principles of use of the material (and its removal) will be taught for some time to come. This knowledge is important to planning curriculum changes needed to prepare graduates for clinical practice.

SUMMARY Objective: To evaluate the clinical performance of a glass hybrid restorative compared with a resin composite in the restoration of large and deep Class II cavities after 24 months. Methods and Materials: A total of 108 extended size, with the width of the proximal box not interfering with the peak of the cusps and the proximal box in occlusion, Class II lesions in 37 patients were either restored with a glass hybrid restorative or with a micro-hybrid composite resin in combination with selective etching by two experienced operators according to the manufacturer's instructions. Two independent examiners evaluated the restorations at baseline and at the six-, 12-, 18-, and 24-month recalls according to the modified US Public Health Service criteria. Negative replicas at each recall were observed under scanning electron microscopy (SEM) to examine surface characteristics. Data were analyzed statistically. Results: After 24 months, 90 restorations were evaluated in 32 patients (recall rate: 86.5%). Four glass hybrid restorations were missing; three were due to bulk and one was due to proximal fracture at 12 months. Only six restorations were scored as bravo at baseline and at the six-, 12-, 18-, and 24-month recalls for color (p0.05). SEM observations exhibited acceptable surface and marginal adaptation characteristics for both restorative materials at 24 months. Conclusions: Although glass hybrid restorations showed significant mismatch in color, both restorative materials exhibited successful performance for the restoration of large Class II cavities after 24 months.

SUMMARY Purpose: The purpose was to perform a systematic review and meta-analysis based on the following research question: do tooth- and cavity-related aspects of noncarious cervical lesions (NCCLs) affect the retention of composite restorations? Methods: Randomized clinical trials (RCTs) that evaluated the retention rate of resin restorations in NCCLs were included for the identification and comparison of their characteristics. The search was conducted in PubMed and adapted for Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database (LILACS), Brazilian Library in Dentistry (BBO), Cochrane Library, and System for Information on Grey Literature in Europe (SIGLE) without restrictions until July 2018. Unpublished and ongoing trial registries were also searched. The Cochrane Collaboration tool was used for assessing risk of bias. The quality of the evidence was graded using the Grading of Recommendations: Assessment, Development and Evaluation. Using the random effects model, a meta-analysis was conducted for each aspect (arch distribution, tooth location, wear facets, dentin sclerosis, shape, size, depth, occluso-gingival distance, and margin location). Results: We retrieved 6738 articles. After removal of duplicates and nonrelevant articles, 24 RCTs remained. The anterior tooth location favored the retention rates of restoration of NCCLs (relative risk [RR], 1.08; 95% confidence interval [CI], 1.00-1.16). The presence of wear facets is a risk factor for the retention of restorations (RR, 0.91; 95% CI, 0.83-0.99). The evidence was moderate for arch distribution and low or very low for all other factors because of heterogeneity, imprecision, and inconsistency. Conclusion: The tooth location and the presence of wear facets can affect the retention of composite resins in NCCLs.

Clinical Relevance Secondary caries are the main reason for the failure of restorations, class II being the most affected. Techniques that promote less gap percentage are important. Flowable bulk fill composites used at such locations have been shown to decrease gap formation while being a faster procedure than an incremental technique. SUMMARY Purpose: To evaluate gap formation of class II restorations, resin-filling techniques using microcomputed tomography (μCT) and scanning electronic microscopy (SEM) are discussed. Methods and Materials: Class II cavities were prepared in 30 third molars and analyzed in distal and mesial views. Prime&Bond Universal adhesive was applied in all teeth and divided into five groups (n=6): G1, SS+HIT (Spectra Smart+Horizontal Incremental Technique); G2, SS+OBL (Oblique Incremental Technique); G3, SDR+BFT (Surefil SDR+Bulk Fill Technique); G4, SDR+SS (SDR placed on cervical floors from mesial and distal boxes (not light cured), followed by incremental layering with SS and light curing incrementally with the horizontal technique); and G5, BEZ+BFT (Bulk EZ+BFT). All light-curing procedures were performed with high-mode/1200 mW/cm2, Bluephase Style 20i. Teeth were scanned twice (first scan, empty tooth; second scan, filled tooth after light curing) by μCT. Acquired μCT data were evaluated with software looking for gaps at the external mesial and distal margins and submitted to statistical analysis (one-way analysis of variance and least significant differences post hoc test). Validation of the μCT analysis was performed by SEM. Results: G5 showed the lowest gap formation percentage, similar to G4 (p=0.20). G4 also showed statistical similarities to G1 and G3 (p>0.05). G2 showed the highest percentages, similar to G1 (p=0.10) but different from the rest of the groups (p Conclusions: The dual-cure composite and the use of flowable nonpolymerized plus horizontal filling technique showed the best marginal adaptations. The μCT technique was validated for visualization of gap formation after being compared to the SEM technique.

SUMMARY The objective of this study was to evaluate the 24-month clinical performance of three different bulk-fill restorative resin materials in class II restorations. Forty patients with at least three approximal lesions in premolar and molar teeth participated in the study. A total of 120 class II cavities were restored using Tetric EvoCeram Bulk Fill (n=40), SureFil SDR flow + Ceram.X mono (n=40), and everX Posterior + G-aenial Posterior (n=40) with their respective adhesives according to the manufacturers' instructions. All restorations were placed by one operator. The restorations were evaluated at baseline and at six, 12, 18, and 24 months using modified US Public Health Service criteria by one examiner. The restoration groups for each category were compared using the Pearson chi-square test, while the Cochran Q-test was used to compare the changes across different time points within each restorative material (p0.05). At the 24-month recall, two restorations from the SureFil SDR flow + Ceram.X mono group and four from the everX Posterior + G-aenial Posterior group showed slight marginal discoloration and were rated as bravo. No marginal discoloration was observed in any of the Tetric EvoCeram Bulk Fill restorations. Six restorations from the Tetric EvoCeram Bulk Fill group, six from the SureFil SDR flow + Ceram.X mono group, and 12 from the everX Posterior + G-aenial Posterior group received bravo scores in terms of marginal adaptation. No difference was found among the three groups for any of the evaluation criteria tested (p>0.05). There were statistically significant differences between the baseline and 24-month recall in the everX Posterior + G-aenial Posterior group in terms of marginal discoloration (p

Clinical Relevance The use of filled adhesive systems does not influence the clinical performance of the adhesive restoration in noncarious cervical lesions. SUMMARY Objective: The aim of this meta-analysis was to investigate the clinical performance of filled vs unfilled adhesive systems when applied in noncarious cervical lesions. Methods and Materials: A systematic search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library, and SIGLE. Gray literature was also screened. Only randomized controlled clinical trials were included. The risk of bias of the studies was evaluated using the Cochrane Collaboration’s tool. A random-effects meta-analysis was conducted to compare the retention rate, marginal discoloration, and secondary caries of noncarious cervical lesions restored with filled adhesives vs unfilled adhesives. The quality of the body of evidence was assessed using the GRADE approach. Results: A total of 3662 studies were identified after removal of duplicates. Twenty-nine studies remained for qualitative analyses and 28 studies for the meta-analysis. Only one study was judged to have a low risk of bias, and the other 28 were considered to have unclear risk of bias. There was no statistically significant difference between filled adhesives compared with unfilled adhesives in relation to loss of retention, marginal discoloration, or secondary caries at any of the follow-up periods (12–18 months, 24–30 months, 3 years, and 5 years or longer). The quality of evidence was graded as moderate for most outcomes at the respective follow-ups, except when there was an explained heterogeneity, which occurred mainly for loss of retention at the 12-month to 3-year follow-up. The results did not depend on whether microfilled or nanofilled adhesives had been investigated. Conclusions: The addition of fillers into the composition of adhesive systems did not increase the clinical performance (retention rates, marginal discoloration, or secondary caries) of composite restorations placed in noncarious cervical lesions when compared with unfilled adhesives.

Introduction There has been speculation about early exfoliation of carious primary molar teeth treated with the Hall Technique (HT).Aim To investigate the hypothesis that there is a difference in exfoliation times between teeth treated with the HT and contralateral teeth not treated with the HT.Methods Split-mouth retrospective cohort study of children treated in Dundee Dental Hospital and School (DDHS). Radiographs and clinical records were assessed to compare children's ages at exfoliation for HT-treated primary molars and their contralateral teeth not treated with the HT. Primary molars' root resorption was also evaluated to assess whether the HT influenced the rate of root resorption.Results Using DDHS's clinical systems, children's records (n = 13,160) were screened for children's ages and sequential radiographs, with 192 children potentially eligible. After assessing radiographs and clinical records, 39 children met the inclusion criteria. Their mean age at time of HT treatment was 7.2 years (range = 4.0 to 11.0; SD = 1.5). There was no evidence of a difference (p = 0.41) between children's ages at exfoliation of HT teeth (10.7; SD = 1.2 years) and contralateral teeth (11.0; SD = 1.4 years).Conclusion There is no evidence that use of the Hall Technique is associated with early exfoliation of primary molars.

OBJECTIVES: The objectives of this cross-sectional survey were to determine the prevalence of secondary caries (SC) in general population, to identify patient- and material-related factors which may affect the prevalence, and to describe some clinical characteristics of SC lesions. MATERIALS AND METHODS: A total of 4036 restorations in 450 patients, who visited the university dental clinic for a regular (half) yearly checkup, were examined clinically (and radiographically) for the presence of SC. Clinical characteristics of the detected SC lesions (size, activity, and location) and the planned treatment were recorded. In addition, patients' caries-risk status was assessed according to the modified "cariogram" model. RESULTS: In total, 146 restorations were diagnosed with SC, which gives an overall prevalence of 3.6%. Restorative material, restoration class, patient's caries risk, and smoking habits were shown to be important factors, as SC prevalence was significantly higher with composites, class II restorations, high-caries-risk patients, and smokers. Restorations' gingival margins were most frequently affected by SC. The largest number of restorations with SC (72%) was scheduled for the replacement. CONCLUSIONS: Prevalence of SC was higher with composite than with amalgam restorations, irrespective of the patient's caries-risk status. Gingival margins of class II, including MOD restorations, seem to be the place of less resistance to SC development. Management of SC seems to place a considerable burden on the health care workforce and expenditure. CLINICAL RELEVANCE: Secondary caries (SC) is considered to be the main cause of dental restoration failure and one of the biggest clinical challenges related to dental composites. Nevertheless, its prevalence in daily practice is still not clear, which impedes an accurate estimation of its impact on health care costs. ispartof: CLINICAL ORAL INVESTIGATIONS vol:24 issue:2 pages:683-691 ispartof: location:Germany status: published

Marginal adaptation is an important feature of implant-supported crowns, ensuring long-term survival and the success of the prosthetic restoration. The long-term success of a fixed prosthesis such as an implant is highly associated with its marginal adaptation. Improper marginal adaptation increases the risk of plaque accumulation, which leads to decay and periodontal diseases and eventually results in the failure of the fixed dental restoration. The aim of this study is to evaluate the marginal fit of different types of implant-supported crowns following the cementation procedure. It is a retrospective study conducted by reviewing 86,000 patient case records of the Saveetha Dental College and Hospital, Chennai, India. A total of 196 consecutive case records of patients for a period of June 2019 to March 2020, with signed informed consent, were retrieved and analyzed. Information such as patient name, patient identification number (PID), age, gender, marginal adaptation, and type of materials was retrieved from patient case records. Data were entered in Excel and analyzed using SPSS software version 23.0. Descriptive analysis was done for the assessment of age, gender, type of materials, and marginal adaptation. A Chi-square test was used to evaluate the association between marginal adaptation and type of materials. The significant level was set at less than or equal to 0.05 (p ≤ 0.05). In this study, we observed that all-metal, metal-ceramic, hand-layered, and monolithic crowns mainly have smooth margins adaptation (52.55%) following cementation. The placement of implant-supported crowns is mostly done in individuals within the 21-30 years age group (29.08%). A higher prevalence of implant-supported crowns is seen in males (61.73%) compared to females (38.27%). Within the limits of the study, placement of implant-supported crowns is done mainly in individuals within the 21-30 years age group, with higher predilection in males compared to females. Metal-ceramic crowns are commonly placed, followed by hand-layered crowns, monolithic crowns, and all-metal crowns. Most of the implant-supported crowns exhibit satisfactory marginal adaptation with smooth margins. However, there is no significant association between the types of material and marginal adaptation.

SUMMARY Purpose: This study aimed to characterize and analyze the number of voids and the percentage of void volume within and between the layers of class II composite restorations made using the bulk fill technique or the incremental technique by optical coherence tomography (OCT). Methods and Materials: Class II cavities (4×4×2 mm) were prepared in 48 human third molars (n=24 restorations per group, two class II cavities per tooth). Teeth were divided into four groups and restored as follows: group 1 (FOB), bulk filled in a single increment using Filtek One Bulk Fill (3M Oral Care); group 2 (FXT), incrementally filled using four oblique layers of Filtek Z350 XT (3M Oral Care); group 3 (FBF+FXT), bulk filled in a single increment using Filtek Bulk Fill Flowable Restorative (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care), and group 4 (FF+FXT), incrementally filled using Filtek Z350 XT Flow (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care). After the restorative procedure, specimens were immersed into distilled water and stored in a hot-air oven at 37°C. Forty-eight hours later, thermal cycling was conducted (5000 cycles, 5°C to 55°C). Afterward, OCT was used to detect the existence of voids and to calculate the number of voids and percentage of voids volume within each restoration. Data were submitted to chi-square and Kruskal-Wallis tests (α=0.05). Comparisons were made using the Dunn method. Results: Voids were detected in all groups, ranging from 0.000002 (FBF+FXT and FF+FXT) to 0.32 mm3 (FBF+FXT). FF + FXT presented voids in all of the restorations and had a significantly higher number of voids per restoration when compared to the other groups (p Conclusions: The use of flowable resin-based composites can result in an increased number of voids and percentage of voids volume in restorations, and this appears to be more related to voids present inside the syringe of the material than to the use of incremental or bulk fill restorative techniques.

SUMMARY Aim: The aim of this study was to quantitatively compare conventional composite removal and composite removal supported by the fluorescence-aided identification technique (FIT) regarding the completeness, selectivity, and duration of the procedure in directly restored permanent posterior teeth. Methods and Materials: Two operators removed standardized direct class II composite restorations (n=32 per operator) in human tooth models under simulated clinical conditions. According to a randomized allocation scheme, removal was performed with either the conventional technique (contra-angle handpiece) or supported by FIT. The duration of each removal procedure was recorded. The completeness and selectivity were volumetrically assessed through superimposition of three-dimensional surface scans. Statistical significance was tested by examining the overlap of 95% confidence intervals (CI). Multiple comparison was performed with Tukey tests for each variable. Results: Compared with the conventional technique, composite removal with FIT was faster (329 seconds [95% confidence interval (CI): 268-390 seconds] vs 179 seconds [95% CI: 150-208 seconds]), generated less tooth substance loss (4.53 mm3 [95% CI: 3.77-5.30 mm3] vs 2.77 mm3 [95% CI: 2.11-3.43 mm3]), and left behind less composite residue (1.58 mm3 [95% CI: 1.23-1.94 mm3] vs 0.53 mm3 [95% CI: 0.39-0.67 mm3]). Conclusion: Within the limitations of this in vitro study, FIT facilitated the selective and expeditious removal of tooth-colored composites in directly restored posterior teeth.

SUMMARY Objectives: The aim of this clinical study was to evaluate the clinical performance of Class II restorations of a high-viscosity glass ionomer material, of a bulk-fill composite resin, and of a microhybrid composite resin. Methods and Materials: One hundred nine Class II restorations were performed in 54 patients using three different restorative materials: Charisma Smart Composite (CSC; a conventional composite resin), Filtek Bulk Fill Posterior Restorative (FBF; a high-viscosity bulk-fill composite), and Equia Forte Fil (EF; a high-viscosity glass ionomer). Single Bond Universal adhesive (3M ESPE, Neuss, Germany) was used for both conventional and bulk-fill composite resin restorations. The restorations were evaluated using modified US Public Health Service criteria in terms of retention, color match, marginal discoloration, anatomic form, contact point, marginal adaptation, secondary caries, postoperative sensitivity, and surface texture. The data were analyzed using the chi-square, Fisher, and McNemar tests. Results: Eighty-four restorations were evaluated at two-year recalls. There were clinically acceptable changes in composite resin restorations (FBF and CSC). In addition, no statistically significant difference was observed between the clinical performances of these materials in terms of all criteria (p>0.05). However, there was a statistically significant difference between the EF group and the FBF and CSC groups in all parameters except for marginal discoloration, secondary caries, and postoperative sensitivity (p Conclusions: The tested bulk-fill and conventional composite resins showed acceptable clinical performance in Class II cavities. However, if EF is to be used for Class II restoration, its use should be carefully considered.

Background/purpose: Studies suggested that presence and size of overhanging restoration margins play role in alveolar bone loss. The aim of this study was to determine the prevalence and distribution of overhanging approximal restorations, to evaluate the effect of presence and size of overhang on bone loss using cone beam computed tomography (CBCT) reformatted panoramic images, and to encourage the use of CBCT in retrospective studies on restorative dentistry. Materials and methods: CBCT images of 382 patients with approximal restorations were included in the study. On CBCT images, alveolar bone loss adjacent to each restored surface was determined and compared to the control tooth. The overhang size was measured and categorized as small, medium, or large. Data obtained were evaluated statistically using Kruskal Wallis, Mann Whitney U, chi-square, and one-sample chi-square tests with a significance level set at P < 0.05. Results: A total of 216 (32.4%) surfaces with overhanging restorations were detected in CBCT images. The number of overhanging surfaces with alveolar bone loss (71.3%) was higher than the control surfaces with bone loss (49.1%) (P < 0.05). The amount of bone loss adjacent to overhanging surfaces (2.28 1.69 mm) was significantly higher compared to control surfaces (1.53 1.73 mm) (P < 0.05). However, the same trend applied to the surfaces without overhang and their controls. The amount of bone loss was not correlated with the overhang size (P > 0.05).

Dental adhesives are vital for the success of dental restorations. The objective of this study is to make strong and durable dental adhesives that are free from 2 symbolic methacrylate-based dental resins—2-bis[4-(2-hydroxy-3-methacryl-oxypropoxy)-phenyl]-propane (Bis-GMA) and 2-hydroxyethyl-methacrylate (HEMA)—and have equivalent/improved bonding strength and durability. We formulated, prepared, and evaluated 2 dental adhesives using mixtures of a hydrolytically stable ether-based monomer, triethylene glycol divinylbenzyl ether (TEG-DVBE), with urethane dimethacrylate (UDMA) or pyromellitic glycerol dimethacrylate. These adhesives were composed of equimolar ester-/ether-based vinyl functional groups. They were compared with Bis-GMA/HEMA-based commercial and experimental dental adhesives in terms of shear bond strength and microtensile bond strength (µTBS) to human dentin and the µTBS bond stability under extended thermocycling challenges. In addition, the resins’ infiltration to dentin tubules, mechanical performance, and chemical properties were assessed by scanning electron microscopy, ISO standard flexural strength and modulus measurements, contact angle measurements, and water sorption/solubility measurements. The hybrid TEG-DVBE-containing dental adhesives generated equivalent shear bond strength and µTBS in comparison with the controls. Significantly, these adhesives outperformed the controls after being challenged by 10,000 thermocycles between 5 °C and 55 °C. Water contact angle measurements suggested that the hybrid dental adhesives were relatively more hydrophobic than the Bis-GMA/HEMA controls. However, both TEG-DVBE-containing adhesives developed more and deeper resin tags in dentin tubules and formed thicker hybrid layers at the composite-dentin interface. Furthermore, the water solubility of UDMA/TEG-DVBE resins was reduced approximately 89% in comparison with the Bis-GMA/HEMA controls. The relatively hydrophobic adhesives that achieved equivalent/enhanced bonding performance suggest great potentials in developing dental restoration with extended service life. Furthermore, the TEG-DVBE-containing materials may find wider dental applications and broader utility in medical device development.

OBJECTIVES This laboratory study aimed to assess the effects of ultrasonic instrumentation, simulating 10 years of supportive periodontal therapy (SPT), on single-unit crowns. MATERIALS AND METHODS Standardized crowns were fabricated from porcelain-fused-to-metal (PFM) (n = 12), zirconia (ZrO2) (n = 12), lithium disilicate (LDS) (n = 12), feldspar ceramic (FSFC) (n = 6), and polymer-infiltrated ceramic network material (PICN) (n = 6). The crowns, luted on PICN abutments with resin-based luting material (RBLM), and if applicable glass ionomer cement (GILC), underwent thermal cycling and trimonthly ultrasonic instrumentation. After 1 and 10 years of simulated SPT, restoration quality assessments were performed, comprising profilometric surface roughness measurements, marginal integrity evaluations, and scores for luting material remnants and visible cracks. The statistical analysis included multiple logistic regressions with nested designs (α = 0.05). RESULTS During simulated SPT, bulk fractures (n = 2) and a de-cementation failure (n = 1) of LDS and ZrO2 crowns were observed. No significant change in roughness was detected after 10 years (p = 0.078). Over time, marginal defects increased (p = 0.010), with PFM crowns showing the highest rate of chippings at sites with a narrow shoulder. Fewer marginal defects were detectable on crowns luted with RBLM compared with GILC (p = 0.005). Luting material remnants decreased during SPT (p

To evaluate the effects of different types of restorations on observer ability to detect proximal caries in CBCT images. Forty human premolars and molars with artificial proximal caries were placed proximal and distal to 5 molars having different restorations (amalgam, composite, resin-modified glass ionomer cement (RMGIC) fillings, zirconia, and lithium disilicate crowns) and a non-restored molar. CBCT scans were obtained using i-CAT® Next Generation. Images were rated twice by 2 observers. The exact depth of artificial caries was histologically established. Sensitivity, specificity, and area under the receiver operating characteristic curve (Az) values were calculated. Caries detection in teeth surfaces mesial and distal to amalgam showed compromised specificity and accuracy. Moreover, caries detection in teeth surfaces mesial to zirconia crown showed low sensitivity, specificity, and accuracy. Capability of CBCT in detection of proximal caries in teeth adjacent to composite, RMGIC, and lithium disilicate was comparable to those adjacent to non-restored molar. CBCT scans performed for tasks other than caries detection should be assessed for proximal caries in absence of any restorations as well as in presence of composite, RMGIC fillings, and lithium disilicate crowns. However, CBCT should not be used for proximal caries detection in teeth adjacent to amalgam and teeth surfaces mesial to zirconia crowns. It is important to investigate the influence of artifacts produced by various restorations on CBCT-based caries detection to optimize CBCT benefits, caries diagnosis and avoid unnecessary treatment of sound surfaces.

Objectives Magnesium phosphate–based cements begin to catch more attention as bone substitute materials and especially as alternatives for the more commonly used calcium phosphates. In bone substitutes for augmentation purposes, atraumatic materials with good biocompatibility and resorbability are favorable. In the current study, we describe the in vivo testing of novel bone augmentation materials in form of spherical granules based on a calcium-doped magnesium phosphate (CaMgP) cement. Materials and methods Granules with diameters between 500 and 710 μm were fabricated via the emulsification of CaMgP cement pastes in a lipophilic liquid. As basic material, two different CaMgP formulations were used. The obtained granules were implanted into drill hole defects at the distal femoral condyle of 27 New Zealand white rabbits for 6 and 12 weeks. After explantation, the femora were examined via X-ray diffraction analysis, histological staining, radiological examination, and EDX measurement. Results Both granule types display excellent biocompatibility without any signs of inflammation and allow for proper bone healing without the interposition of connective tissue. CaMgP granules show a fast and continuous degradation and enable fully adequate bone regeneration. Conclusions Due to their biocompatibility, their degradation behavior, and their completely spherical morphology, these CaMgP granules present a promising bone substitute material for bone augmentation procedures, especially in sensitive areas. Clinical relevance The mostly insufficient local bone supply after tooth extractions complicates prosthetic dental restoration or makes it even impossible. Therefore, bone augmentation procedures are oftentimes inevitable. Spherical CaMgP granules may represent a valuable bone replacement material in many situations.

Objective Resin-based composites are widely used in dental restorations; however, their volumetric shrinkage during polymerization leads to several issues that reduce the restoration survival rates. For overcoming this problem, a deep study of shrinkage phenomena is necessary. Methods In this study, micro-tomography (μ-CT) is combined with digital volume correlation (DVC) to investigate the effect of several factors on the polymerization strain of dental composites in model cavities: the presence/absence of an adhesive, the use of transparent/blackened cavities, and irradiation times between 1 and 40 s. Results The results indicate that the presence of an adhesive at the interface between the cavity and composite does not reduce the total strain but instead limits it to a preferential direction. In addition, regardless of the conditions, the main strain is generated along the axis parallel to the polymerization irradiation (the vertical axis). Finally, the total strain appears to occur in the first 5 s of irradiation, with no further evolution observed for longer irradiation times. Significance This work provides new insight into resin-based composite shrinkage and demonstrates the benefit of coupling DVC and μ-CT to better understand the degradation mechanisms of these materials.

SUMMARY Two cases of complicated crown fracture of the maxillary incisors were restored using the fragment reattachment technique. Root canal treatment was performed, and the fractured fragment was bonded to the tooth structure using a dentin adhesive system and a flowable composite resin, followed by the insertion of a fiber post using dual-cured resin cement. Reattached fragments have shown reliable prognosis without inflammatory signs around bonded junctions after long-term follow-up.

Aim: To assess the efficacy of treatment using a minimally invasive approach (selective removal of carious tissue, restoration and preventive strategies) in immature permanent molars with MIH. Design: A total of 281 patients, aged 6-8 years, with carious lesions (ICDAS 5-6), severe MIH, and incomplete root formation (one tooth/patient) were included. After clinical and radiographic examinations, selective carious tissue removal was performed, and the teeth received interim restoration for 6 months and were then restored with composite resin. Clinical and radiographic follow-up was undertaken, 6, 12, 18, and 24 months. A protocol of preventive oral care measures was established and repeated at each follow-up, including diet counselling, oral hygiene instruction, dental plaque control, and topical application of fluoride varnish containing CPP-ACP. All clinical procedures and evaluations were done by a single operator. Results: Clinical and radiographic success was observed 24 months after treatment in 96.8% of the cases. Failures were due to enamel fracture at restoration margins, resulting in pulpitis and absence of apex closure. Conclusion: Selective removal of carious tissue, interim, and subsequently definitive restoration, combined with home and professional preventive measures, maintained marginal integrity of restorations in immature permanent molars with severe MIH, confirmed by pulp vitality and occurrence of apexogenesis.

The aim of the present study was to evaluate the clinical performance of a glass hybrid restorative compared with a nano-ceramic composite resin in non-carious cervical lesions (NCCLs) of patients with bruxism.Twenty-five patients with NCCLs and bruxism were enrolled in the present study. Before treatment, the dimensions of the NCCLs (depth, cervico-incisal height, and mesio-distal width) and internal angles were measured. Degree of tooth wear (TWI) and gingival conditions were recorded. A total of 148 NCCLs were randomly restored with a glass hybrid restorative system (GH) (Equia Forte Fil, GC, Tokyo, Japan) or a nano-ceramic composite resin (RBC) (Ceram.X One Universal, Dentsply, DeTrey, Konstanz, Germany). The restorations were evaluated at baseline and after 6, 12, and 24 months according to the modified USPHS criteria. Data were analyzed with Pearson's chi-square, Fisher's exact, Mann-Whitney U, and Cochran's Q tests (P 0.05).At the 24-month recall, 126 restorations in 22 patients were evaluated. The recall rate was 88.0%. No significant difference was found between the materials for retention (P = 0.285), and no relationships were found between internal angle, depth, cervico-incisal height, or mesio-distal width and retention of the restorations (P 0.05). A significant difference was observed between the materials for marginal adaptation (P = 0.002), but no relationships were found among depth, cervico-incisal height, and mesio-distal width and marginal adaptation (P 0.05). RBC showed better results for marginal adaptation. Between marginal adaptation, TWI, and the gingival index, correlations were significant (P 0.001, P = 0.002). A significant change was found in marginal discoloration in GH and RBC over time (P = 0.039 and P = 0.004, respectively). Neither secondary caries nor tooth sensitivity was observed on any of the restorations at any evaluation.Although nano-ceramic RBC showed better marginal adaptation than GH, both tested restoratives showed clinically acceptable performance for the restoration of NCCLs of patients with bruxism after 24 months of clinical service.This study is registered on http://clinicaltrials.gov under protocol record KA-16020, Clinical Performance of a Glass Hybrid Restorative in NCCL's of Patients With Bruxism.