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Selective laser melting (SLM) additive manufacturing (AM) technologies provide an alternative to conventional casting and milling procedures in fabricating metal-ceramic dental prostheses. However, the quality of porcelain bond strength to the SLM AM cobalt-chromium (Co-Cr) metal framework of a dental restoration is unclear.The purpose of this systematic review and meta-analysis was to identify in vitro studies that reported the porcelain bond strength to SLM AM Co-Cr dental metal alloys and compare the porcelain bond strength values to cast, milled, and additively manufactured Co-Cr dental alloys.An electronic systematic review was performed in different databases: MEDLINE/PubMed, EMBASE, World of Science, Cochrane, and Scopus. A manual search was also conducted. Studies that reported the porcelain bond strength to SLM Co-Cr metal alloys and in the English language were included. Two investigators evaluated the quality assessment of the studies by applying the JBI critical appraisal checklist for quasi-experimental studies (nonrandomized experimental studies). A third investigator was consulted to resolve lack of consensus. Two subgroups were created based on the test used, 3-point bend and shear bond strength tests. The porcelain bond strength of cast, milled, and AM Co-Cr dental alloys were compared. The I2 statistic and its associated P value were used to assess the heterogeneity between studies. The Eger test was used for determining significance of the funnel pots.A total of 216 studies were collected from the electronic and manual searches. After independently evaluating the titles and abstracts by the reviewers, 26 articles were identified. Three of these were excluded after full-text revision. The porcelain bond strength comparison between the cast and AM alloys for the 3-point bend subgroup revealed a significant result for overall effect (P.001) favoring the SLM method with considerable heterogeneity (I2=83%, P.001). Furthermore, the porcelain bond strength comparison between cast and milled alloys for the shear bond strength subgroup revealed a significant test for overall effect (P=.04) favoring milled procedures with a nonsignificant unimportant heterogeneity (I2= 0%, P.47) and for the 3-point bend subgroup (P.001) favoring milled specimens with a significant considerable heterogeneity (I2=79%, P.001).The metal manufacturing method had no effect on the porcelain bond strength to Co-Cr dental metal alloys.

The restoration of class II cavities is predominantly carried out with composite materials. Due to the high failure rate in restoring this type of cavity, composite materials with much-improved properties and new application techniques have been promoted. The study aimed to analyze the mechanical behavior of several topical composite materials (nanocomposites, nanohybrids and ormocer) using different application techniques. In a lower second molar, a class II occlusal cavity was prepared. As filling materials, we used the following combinations: Admira Fusion and Admira Fusion Flow, Grandio and Grandio Flow, Filtek Supreme XT and Filtek Supreme Flow. These were applied using a snow plow, injection molded and Bichacho techniques. Three-dimensional scanning of the molar with the prepared cavity was performed, and then scanning of each layer of added composite material was performed, obtaining three-dimensional models. The virtual molar models were analyzed with software specific to the finite element analysis method, where their physical-mechanical properties were entered and assigned to the components of the virtual molar. Simulations at high forces specific to bruxism were then carried out and analyzed, and compared. The values of displacements and strain, for all six analyzed situations, are relatively small (range from 5.25 × 10−6–3.21 × 10−5 for displacement, 6.22 × 10−3–4.34 × 10−3 for strain), which validates all three methods and the materials used. As far as the stress values are concerned, they are similar for all methods (250–300 MPa), except for the snow plow and injection-molded techniques using Grandio and Grandio Flow composites, where the maximum von Mises stress value was more than double (approximately 700 MPa). When using the combination of Grandio and Grandio Flow materials, the 1 mm thickness of the fluid composite layer was found to have a major influence on occlusal forces damping as opposed to 0.5 mm. Therefore, the Bichacho technique is indicated at the expense of the snow plow and injection-molded techniques. The composite materials used by us in this study are state-of-the-art, with clear indications for restoring cavities resulting from the treatment of carious lesions. However, their association and application technique in the case of Class II cavities is of clinical importance for resistance to masticatory forces.

Background and Objectives: This study aimed to evaluate the surface roughness evolution of several finished and polished composites when bleaching materials are applied. The research was conducted on four microhybrid or nanofilled composites that are used in dental restorations. Materials and Methods: For each composite type, 5 samples were selected for control, 5 samples were subjected to the bleaching protocol “office bleach” with 40% hydrogen peroxide, and 5 other samples were subjected to the “home bleach” protocol with 16% carbamide peroxide, resulting in a total number of 60 samples. The surfaces of all the samples were tested for roughness, and the values of the most relevant parameter (Ra), were collected. Comparisons between composites and samples were performed using one-way ANOVA (in Statistical Package for Social Sciences). Results: After the bleaching protocol with 40% hydrogen peroxide gel, it was found that the roughness of the group increased considerably compared to the control group, so the highest roughness was found at GC Gradia direct anterior group, and the lowest value was registered for the 3M ESPE Valux Plus group. Following the bleaching protocol with 16% carbamide peroxide (home bleach), it was noted that the sample surfaces were not as affected. In this case, the lowest roughness was found at 3M ESPE Valux Plus group, and the highest roughness was registered for the GC G-aenial anterior group. Following the interpretation of the results, all four types of dental composites tested showed significant surface roughness differences between the groups subjected to bleaching protocols and those kept as control (p < 0.05). Conclusions: The surfaces of the samples were affected by the bleaching protocols by increasing the roughness compared to the control samples.

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.

Objective. This study investigated the effects of flowable resin composites (FCR) on the restoration of noncarious cervical lesions (NCCL) and their impact on periodontal tissues. Materials and Methods. 30 periodontally healthy patients were assigned into three groups randomly; group VF: self-adhering FCR, group NF: fluoride-releasing FCR, and group SF: microhybrid FCR. Gingival crevicular fluid (GCF) volume levels of osteoprotegerin (OPG), immunoglobulins (IgA, IgM), and interleukins (IL-1, IL-1β, and IL-10) in GCF were analyzed with ELISA tests. Clinical success rates were evaluated using USPHS criteria during the 12-month follow-up. Results. The GCF volume was increased mostly in group SF ( 1.34 ± 0.09 μ l ). While the titer of interleukin was increased in all groups, higher increases were observed in IL-1 and IL-1β in group NF (170.78 pg/ml and 39.35 pg/ml). Increased IL-10 was observed in group VF ( 14.33 ± 0.85 pg / ml ). IgA levels varied partially among all groups ( p > 0.05 ), and even IgM levels were elevated immediately after the restoration process but returned to normal on the 28th day ( p < 0.05 ). Group NF failed in most of the USPHS criteria, while the material group VF and group SF presented acceptable results except in the marginal adaptation criterion ( p < 0.05 ). Conclusions. Clinical efficacy of self-adhering FCR was found the best for restoration of NCCL while fluoride-releasing FCR stimulated the periodontal response and had negative effects on GCF volume, cytokine, and immunoglobulin levels.

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.

We introduce a new digital workflow to fabricate a fixed partial denture (FPD) utilizing the three-dimensional surface morphology of provisional restoration (PR) and abutment teeth. Scanned images of the full maxilla with abutment teeth, full maxilla with PR, and PR alone were superimposed. The surfaces of the final FPD were designed based on the entire morphology of the PR and abutment teeth surfaces. The inner and outer surfaces converged at the margin lines of the abutment teeth. Fine modifications to the final FPD design were performed manually, and the final FPD was fabricated and successfully installed in the patient.

Leucite and zirconia are commonly used in the production of prosthetic dental materials. Leucite presents attractive optical properties but low toughness and wear resistance, which limits its use. Zirconia has much higher toughness, but due to aesthetic reasons and ageing issues, needs to be glass veneered. Chipping of such veneer is usually responsible for the abnormal wear induced on the antagonist teeth. Leucite reinforced with 25% of nano-zirconia is a promising alternative to overcome these issues, allowing the production of dental restorations without veneer. This study aims to investigate if leucite-zirconia composites have suitable optical, mechanical and tribological properties to be used in dental restoration. Samples with different compositions of leucite and/or nano-zirconia were produced by unidirectional compression and characterized concerning density, surface morphology, roughness, hardness, toughness, and translucency. Wear tests were performed in a chewing simulator using human cusps as counterbodies. Tests were also performed in glazed zirconia for comparison. 25% ZrO2 leads to the lowest wear of the tribological pair among the studied systems, except 100% ZrO2. This can be attributed to the toughening effect of zirconia and reduced size of third body particles. Abrasion was the main wear mechanism observed in this pair. In addition, this was the composite that presented the highest translucency.

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 aims of the current study are to present computational simulations based on the finite element method in order to determine the lowest viable thickness of materials used to make ceramic samples based on the interface of groups of materials (Ni–Cr/ceramics, alumina/ceramics), and samples made of each of these materials, alone; as well as to report the effect of variation in the stress intensity factor of these interfaces (β). Test conditions were simulated in Abaqus CAE software and mesh features focused the crack tip. Fracture toughness analysis was carried out by simulating the three-point bending test (SEVNB specimen of the Fracture Mechanic standards). Based on the present results, the lowest material thickness necessary to meet the stress intensity requirement at the crack tip was 8 mm of each material, under symmetry condition, for sandwich composition. Such a thickness included fracture process zone (FPZ) size and plastic zone (PZ). Sandwich thickness was enough to maintain the test conditions established for the standards. Samples produced in the present study met the requirements of the fracture toughness test, based on the ASTM E−399 standard - specimens with the lowest possible sandwich thickness were obtained and they met the stress intensity requirements of the crack tip. This finding pointed towards a sample based on using a reduced amount of test materials - such as those used for dental restoration. The lowest material thickness in the sandwich was 8 mm, for all groups of materials, under symmetry conditions. This thickness includes fracture process zone size and plastic zone size. The herein proposed sandwich thickness was enough to maintain the test conditions established by fracture mechanic standards.

Multifunctional fillers are greatly required for dental resin composites (DRCs). In this work, a spray dryer with a three-fluid nozzle was applied for the first time to construct high-performance complex nanoparticle clusters (CNCs) consisting of different functional nanofillers for dental restoration. The application of a three-fluid nozzle can effectively avoid the aggregation of different nanoparticles with opposite zeta potentials before the spray drying process in order to construct regularly shaped CNCs. For a SiO2–ZrO2 binary system, the SiO2–ZrO2 CNCs constructed using a three-fluid nozzle maintained their excellent mechanical properties ((133.3 ± 4.7) MPa, (8.8 ± 0.5) GPa, (371.1 ± 13.3) MPa, and (64.5 ± 0.7) HV for flexural strength, flexural modulus, compressive strength, and hardness of DRCs, respectively), despite the introduction of ZrO2 nanoparticles, whereas their counterparts constructed using a two-fluid nozzle showed significantly decreased mechanical properties. Furthermore, heat treatment of the SiO2–ZrO2 CNCs significantly improved the mechanical properties and radiopacity of the DRCs. The DRCs containing over 10% mass fraction ZrO2 nanoparticles can meet the requirement for radiopaque fillers. More importantly, this method can be expanded to ternary or quaternary systems. DRCs filled with SiO2–ZrO2–ZnO CNCs with a ratio of 56:10:4 displayed high antibacterial activity (antibacterial ratio > 99%) in addition to excellent mechanical properties and radiopacity. Thus, the three-fluid nozzle spray drying technique holds great potential for the efficient construction of multifunctional cluster fillers for DRCs.

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.

(1) Background: This in vitro reliability study aimed to determine the inter- and intra-examiner reliability for the detection of direct fillings, indirect crown restorations, root canal fillings and implants on periapical radiographs. (2) Methods: Fourteen dentists (2 years of clinical experience = 3) participated in this diagnostic reliability study in which included a theoretical and practical educational training prior to data collection. The image set of periapical radiographs (N = 150) was examined in two evaluation rounds by all the dentists. Cohen’s Kappa (CK) and a binary logistic regression model were computed. (3) Results: The inter- and intra-examiner reliability were found to be in almost perfect agreement: direct fillings (1st round 0.859/2nd round 0.844/intra 0.910), indirect crown restorations (0.932/0.926/0.955), root canal fillings (0.920/0.886/0.941) and dental implants (0.994/0.988/0.987). The binary logistic regression model revealed that the “evaluation round” and “dentist’s clinical experience” had no significant influence, but for the “diagnostic category”; small, but statistically significant differences were documented. (4) Conclusions: The reliability for detecting direct and indirect restorations, root canal fillings or implants on periapical radiographs was found to be high in the present reliability study on periapical radiographs.

A ceramic inlay is a micro-prosthesis made in a laboratory or dental office by an indirect method. Being an independent construction, it perfectly restores chewing functions, shape, color and aesthetics of a damaged tooth. Ceramics is a durable and stable material that is firmly entrenched in modern dentistry due to its high aesthetic and mechanical properties.

Background The success of rehabilitation in primary teeth may not rely only on the success of dental restoration, as esthetics is also important. As zirconia crowns combine resistance with esthetics, pediatric dentists must know the details regarding this material to be able to use it when required. Objective To review the literature and synthesize research regarding the use of prefabricated zirconia crowns. Material and methods A systematic search of the literature was carried out in PubMed, MEDLINE EBSCO, BVS, Embase, and Scopus, with the search terms: “zirconia crowns”, “zirconia crown”, “prefabricated crowns”, “pediatric crowns”, “zirconia pediatric crown”, “deciduous”,” primary teeth”, “primary tooth”, “pediatric dentistry”, “primary molar” and “primary incisors”. After the screening for inclusion and exclusion criteria, 60 eligible articles were included, in English, Spanish or Portuguese, with no restrictions on the year of publication. Results Zirconia crowns are indicated for primary teeth affected by early childhood caries, traumatic dental injuries and developmental defects of enamel. They present resistance, durability, higher esthetics proprieties (when compared to other materials for the full coronal coverage of primary teeth), good gingival health and biocompatibility, good parental and children's acceptance and satisfaction. However, some limitations are mentioned: higher costs, the necessity for greater amounts of tooth reduction and the impossibility of adjustments. Conclusion Zirconia crowns, as no other material for the full coronal coverage of primary teeth, combine biocompatibility, resistance and ideal esthetic outcomes. This material, despite its limitations, is a great alternative for the rehabilitation of primary teeth with intense loss of structure.

The aim of the study is to create a technique and perform mechanical tests to determine the strength parameters of dental composites from the standpoint of linear fracture mechanics, and using the phenomenon of acoustic emission to determine the origin and development of destruction of light-curing dental composites under quasi-static local compression load. The following hybrid dental composites of domestic and foreign manufacturers were selected for comparison: Latelux (Latus, Ukraine), TETRIC N-CERAM (Ivoclar Vivadent, Liechtenstein), CHARISMA CLASSIC (Kulzer, Germany). 10 disc samples of 13 mm diameter and 5 mm thick of each material were made by using a specially designed mould for study purposes. Packaging and moulding of the material into the mould was performed in laboratory conditions at an air temperature of 18 – 21°C. Before testing, the samples were kept for 24 hours at a temperature of 37°C in saline solution. The samples were loaded on the SVR-5 machine using a ball indenter. During the experiments, acoustic emission data were simultaneously recorded using the SKOP-8 measuring system. In the post-processing stage, the dependencies of the load change during the experiment, the distribution of the amplitudes of the registered AE signals and their sum over time were recorded. The fracture load, indenter displacement, and the features of composite fracture were determined from the obtained dependencies based on the analysis of AE generation under the load. Analysis of the parameters of the AE signals showed that during the destruction of the Tetric N-Ceram composite the signals had the largest amplitude and energy, and of Latelux had the smallest ones.

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.

Although root canal therapy is the most common and widely used treatment at clinical presentation, there are still some postoperative complications. As cell biology and tissue engineering techniques advance rapidly, the use of biological therapy to regenerate dental pulp has become a new trend; Relevant literatures in recent five years were searched using key words such as “root canal therapy”, “Dental pulp stem cells”, “Dental pulp regeneration”, and “Cell homing” in PubMed, Web of Science, etc; Dental pulp stem cells (DPSCs) have multi-differentiation potential, self-renewal capability, and high proliferative ability. Stem cell-based dental pulp regeneration has emerged as a new research hot spot in clinical therapy. Recently, dental pulp-like structures have been generated by the transplantation of exogenous DPSCs or the induction of homing of endogenous DPSCs. Studies on DPSCs are important and significant for dental pulp regeneration and dental restoration; In this review, the existing clinical treatment methods, dental pulp regeneration, and DPSC research status are revealed, and their application prospects are discussed. The stem cell-based pulp regeneration exerts promising potential in clinical therapy for pulp regeneration.

The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics (LDGC) was used as an additive for yttria stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics. The effect of LDGC on the sintering, mechanical, and translucent properties of Y-TZP ceramics was investigated in the present study. The results showed that the LDGC additive effectively improved the densification of Y-TZP at 1100 °C, which was much lower than the sintering temperature for pure Y-TZP. When sintered at 1100 °C, the Y-TZP with 1 wt% LDGC reached a relative density of 95.45%, and prossessed a flexural strength of 482.4 MPa and a fracture toughness of 5.94 MPa·m1/2. Moreover, its translucency was also improved. While, the addition of LDGC could result in an escape of yttrium atoms from the grain lattice of zirconia, which induced the tetragonal-monoclinic transformation of zirconia and abnormal growth of monoclinic grains. The escaped yttrium atoms diffused into the intergranular glass phase. The results indicated that the novel Y-TZP-LDGC ceramics has a great potential to be used for all-ceramic restorations.

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.

This experiment aimed to synthesize a biomimetic mineralized hydrophilic polyurethane dentin primer containing DDDEEKC peptide (DDDEEKC-PU) to fill dentin tubules and induce mineralization. The degree of conversion (DC) was tested. Dentin samples were acid-etched and treated with DDDEEKC-PU. They were immersed in stimulated human fluid (SBF) for 7, 14 and 28 days. Dentin permeability, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Vickers hardness were measured. After 28 days, regenerated minerals were deposited on resin tags which were confirmed to be hydroxyapatite (HAp). The minerals reduced the dentin permeability and improved the microhardness. DDDEEKC-PU was able to fill dental tubules immediately and induce mineralization simultaneously.

Introdução: As resinas bulk fill surgiram da busca por um material estético com propriedades biomecânicas favoráveis e técnica simplificada, tornando-se uma estratégia para procedimentos restauradores em saúde pública. Entretanto, sua aplicabilidade clínica ainda gera incertezas aos profissionais. O presente estudo tem por objetivo analisar, através da revisão de literatura, características, propriedades e aplicabilidade clínica das resinas bulk fill. Metodologia: Estudo bibliográfico, de abordagem qualitativa, do tipo revisão crítica da literatura, realizado nas bases de dados PubMed/MEDLINE, Scopus, Google Scholar e SciELO, selecionando artigos de estudos laboratoriais e clínicos de 2015 a 2020. Resultados: Estudos in vitro e ensaios clínicos randomizados demonstram que resinas bulk fill de consistência regular tem apresentado propriedades mecânicas semelhantes às resinas convencionais. As resinas do tipo bulk fill, nos diferentes graus de viscosidade, podem proporcionar economia de tempo, com uma técnica simplificada e obtenção de resultados satisfatórios. Sugere-se o emprego dessas resinas em amplas reconstruções, situações que requerem agilidade, como atendimento a crianças e pessoas com deficiência, inclusive no serviço público, como alternativa a casos em que se utilizaria o amálgama ou o cimento de ionômero de vidro como material restaurador. Entretanto, atualmente o custo elevado e a maior translucidez de algumas resinas conferindo aparência acinzentada a restaurações aos dentes anteriores, são alguns fatores que contraindicam o seu uso. Conclusão: As resinas bulk fill se apresentam como material indicado para restaurações diretas em dentes posteriores, principalmente pela simplificação da técnica, tornando possível otimizar procedimentos estéticos que demandam maior tempo clínico, sem comprometer a qualidade do tratamento. Introduction: Bulk fill resins emerged from the search for an aesthetic material with favorable biomechanical properties and simplified technique, becoming a strategy for restorative procedures in public health. However, its clinical applicability still causes uncertainties for professionals. The present study aims to analyze, through literature review, characteristics, properties, and clinical applicability of bulk fill resins. Methods: Bibliographic study, with a qualitative approach, of the critical literature review type, carried out in PubMed/MEDLINE, Scopus, Google Scholar and SciELO databases, selecting articles from laboratory and clinical studies from 2015 to 2020. Results: In vitro studies and randomized clinical trials demonstrate that bulk fill resins of regular consistency have shown mechanical properties similar to conventional resins. Bulk fill resins, in different viscosity grades, can save time, with a simplified technique and obtain satisfactory results. It is suggested that the use of these resins in extensive reconstructions, events which require agility, such as care for children and people with disabilities, including in the public service, as an alternative to cases in which amalgam or glass ionomer cement would be used as a restorative material. However, currently the high cost and greater translucency of some resins giving a grayish appearance to restorations to anterior teeth, are some factors that contraindicate their use. Conclusion: Bulk fill resins are a suitable material for direct restorations in posterior teeth, mainly due to the simplification of the technique, making it possible to optimize aesthetic procedures that require more clinical time, without compromising the quality of the treatment. Introducción: Las resinas bulk fill surgieron de la búsqueda de un material estético con propiedades biomecánicas favorables y técnica simplificada, convirtiéndose en una estrategia para procedimientos restauradores en salud pública. Sin embargo, su aplicabilidad clínica aún genera incertidumbres para los profesionales. El presente estudio tiene como objetivo analizar, a través de la revisión de la literatura, las características, propiedades y aplicabilidad clínica de las resinas bulk fill. Metodología: Estudio bibliográfico, con enfoque cualitativo, del tipo revisión crítica de literatura, realizado en las bases de datos PubMed/MEDLINE, Scopus, Google Scholar y SciELO, seleccionando artículos de estudios de laboratorio y clínicos de 2015 a 2020. Resultados: Los estudios in vitro y los ensayos clínicos aleatorizados demuestran que las resinas bulk fill de consistencia regular han mostrado propiedades mecánicas similares a las resinas convencionales. Las resinas bulk fill, en diferentes grados de viscosidad, pueden ahorrar tiempo, con una técnica simplificada y obtener resultados satisfactorios. Se sugiere el uso de estas resinas en reconstrucciones extensas, situaciones que requieran agilidad, como el cuidado de niños y personas con discapacidad, incluso en el servicio público. Sin embargo, actualmente el alto costo y la mayor translucidez de algunas resinas que dan un aspecto grisáceo a las restauraciones de los dientes anteriores, son algunos factores que contraindican su uso. Conclusión: Las resinas bulk fill aparecen como un material indicado para restauraciones directas en dientes posteriores, principalmente por la simplificación de la técnica, permitiendo optimizar procedimientos estéticos que demandan mayor tiempo clínico, sin comprometer la calidad del tratamiento.

Oronasal fistula can persist after conventional secondary alveolar bone graft surgery, which may lead to functional issues, such as regurgitation of fluids from the oral to the nasal cavity. This manuscript describes a clinical case of a patient with a bilateral cleft lip and palate that underwent tongue graft surgery for closure of an oronasal fistula after three failed local mucosa flap surgeries. The multidisciplinary treatment was comprised of orthodontic treatment, mucosa and alveolar grafts for palate closure and aesthetic rehabilitation of the anterior maxillary teeth. Smile aesthetics were noticeably improved, enhancing the patient’s self-perception and confidence.

Objective: This systematic review will be designed to determine which surface treatment provides strong and durable bond strength in the repair of composite resin restorations.

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.

Dental caries is one of the most common chronic childhood diseases and highly prevalent in the world. The commonest treatment procedure for dental caries is a dental restoration which aims to retain the tooth. The survival of restoration depends on the factors associated with restorative materials, patients or operators. Thus, this study aimed to determine the reasons for the failure of restoration in posterior primary teeth performed by undergraduate dental students. A total number of 32 patients aged from 5 to 12 years old were included in this study. Overall, 115 primary molar restorations were assessed clinically using the modified United States Public Health Service Ryge criteria. The O’Leary plaque score was used to evaluate the oral hygiene status of all patients. Then, the data was analysed using the Kaplan-Meier survival curves with log-rank test and Cox regression analysis. 43 (37.4 %) restorations failed with 62.1 % for glass ionomer cement and 36.4 % for composite restorations. Marginal adaptation (62.8 %) is the commonest cause of failure. 76.7% of failure restoration was in patients with poor oral hygiene, and it showed a significant difference compared to patients with moderate and good oral hygiene (p = 0.014). Thus, it was concluded that the type of restorative material and oral hygiene status contributed to the failure of restoration placed in primary molar restorations with failure restoration may occur 2.6 times more in poor oral hygiene patients.

The good mechanical performances and caries inhibition of resin composites (RCs) are of great importance in dental restoration. Generally, the addition of SiO2 can improve the mechanical properties of RCs, while the introduction of fluoride (F) ions is capable of preventing caries. In this work, we first report the use of CaF2/SiO2 core–shell nanoparticles (CaF2/SiO2 NPs) as novel fillers for developing RCs with excellent mechanical properties and sustained F release. The results show that the superior performances of RCs can be obtained by filling 50 wt.% CaF2/50%SiO2 NPs, where the flexural strength, flexural modulus, compressive strength, and hardness were, respectively, increased by 111.5%, 41.4%, 61.7% and 66.8%, compared with the RCs filled with CaF2 nanoparticles. In addition, the initial F-release rate of RCs containing 50 wt.% CaF2/50%SiO2 NPs was 2.5 ± 0.4 μg/(h cm2), while the sustained release rate and the F release ratio were 0.96 ± 0.15 μg/h·cm2 and 5.22‰ after 1632 h (68 days), respectively. It was much more stable and sustained compared with the counterpart filled with CaF2 NPs. Therefore, it could be envisioned that CaF2/SiO2 NPs have a great potential as inorganic fillers in dental RCs.

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).

Background: Provisional dental restoration fabricated to enhance esthetic, stabilization of abutment teeth and maintain function for limited period of time after which it is to be replaced by definitive fixed restoration. The surface roughness of temporary crowns are considered crucial in achieving successful definite restorations. Most bacteria in the oral cavity can only survive on hard and rough surfaces. The objective of the present study is to evaluate and compare the surface roughness of two types of commercially available composite material (Harvard- temp and Charm- temp). The specimens were tested in dry conditions and after two weeks of storage in artificial saliva at 25⁰C. Material and Methods: A total of 32 specimens of dimensions 64mm×10mm×2.5mm were divided in two groups according to the type of material (Harvard-temp or Charm-temp). Each group of material has 16 specimens. These 16 specimens were divided in two groups: a control group (eight specimens) in dry conditions and an aging group (eight specimens) and stored in artificial saliva for two weeks. The TR 200 device was used to measure the surface roughness of specimens in micrometers (µm) before and after aging in artificial saliva. Results: After comparing the results, a significant difference was found in the surface roughness in dry and aging conditions of Harvard – temp (P 0.05). Conclusion: that in-vitro aging research might be an informative predictor of provisional materials’ properties before clinical application. Clinical significance: Both materials can perform adequately in the oral cavity for two weeks. However, the Charm temp mayperform more adequately and maintain good surface roughness.

This study aims to evaluate the effects of different finishing and polishing (F/P) systems on gloss and surface morphology of a new nanocomposite. Thirty discs of Filtek Universal Restorative material (3 M, ESPE) were prepared and divided into six groups (n = 5). Group A and B followed F/P protocols for anterior restorations, whereas Group C and D for posterior ones. Group E represented the control (covered by Mylar strip) and Group F represented the nanocomposite placement by means of clinical hand instruments; Groups E and F did not undergo F/P procedures. Among the polished groups, Group B showed the highest values (68.54 ± 7.54 GU), followed by Group A and D (46.87 ± 5.52 GU; 53.76 ± 2.65 GU). Finally, Group C (37.38 ± 4.93 GU) displayed the lowest results. Overall, Group E showed the highest gloss values (93.45 ± 8.27 GU), while Group F presented the lowest ones (1.74 ± 0.64 GU). Surface analysis revealed that Group A, C, and D displayed a smooth surface. Group B showed the lowest irregularities. Group E exhibited the most uniform superficial morphology. On the other hand, Group F displayed the most irregular one. In conclusion, using the tested material, only two protocols achieved appropriate gloss values. Then, clinicians might use the protocols of Group B and Group D, for anterior and posterior restorations, respectively.

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.

Relevance. Pain localized in the anatomical areas adjacent to the temporomandibular joint is an actual problem for doctors of various specialties.Aim. To develop a diagnostic algorithm and a comprehensive program for the treatment of patients with cervicobrachialgia combined with pathological dental occlusion.Materials and methods. The study involved 90 people of both sexes aged 18 to 55 years; they were divided into 3 clinical study groups (25 people each) and 1 control group (15 healthy individuals). The comparison was carried out depending on the chosen treatment tactics: manual therapy was used in group 1, dental treatment was performed in group 2, a combination of manual therapy and dental rehabilitation with correction of occlusal relationships of the jaws was in group 3.Results. All patients were prescribed pharmacotherapy with NSAIDs to relieve myofascial pain at the level of the muscles of the neck and shoulder girdle. As a result of the study, the most effective algorithm for diagnosis and complex treatment of patients with cervicobrachialgia was identified.Conclusions. Namely, statistically significant positive results were observed in patients of group 3, where manual therapy, pharmacotherapy and complex dental treatment was conducted. In “difficult” patients it is advisable to carry out 3D X-ray visualization, computer functional methods for studying the maxillofacial area and adjacent areas to identify the cause and interrelationships of the patient's disease.

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.

Factors such as aesthetics and adhesion to dental substrates have consolidated composite resin as a restorative material for posterior teeth, however, the performance is unsatisfactory regarding the longevity of these restorations. The purpose of this retrospective cross-sectional observational study was to evaluate the reasons that resulted in failure of class I and II Black composite resin restorations, performed by undergraduate dental students at the State University of Londrina. The patients were selected from the research of the medical charts filed at the University Dental Clinic's Screening Department. The restorations were evaluated by two calibrated dentists. The data collected were tabulated and analyzed using descriptive statistics, function Cont IF. Of the 261 class I and II restorations evaluated, 150 (57.5%) were in need of replacement. The main causes of failure of class I and II restorations were secondary caries (46.7%), followed by fracture (19.3%) and loss of marginal adaptation (16.7%). Of all the restorations made by the 3rd grade students, 68.4% failed, 57.4% performed by the 4th grade students and 53.9% of the 5th grade students. Based on the results, it is concluded that the main reasons for restorations failure were secondary caries, fracture and loss of marginal adaptation according to the evaluation criteria. Restorations performed by students in the 3rd grade showed a higher percentage of failures compared to those performed by students in the 4th and 5th grades. Keywords: Permanent Dental Restoration. Composite Resins. Dental Restoration Failure. Resumo Fatores como estética e adesão aos substratos dentários têm consolidado a resina composta como material restaurador para dentes posteriores, entretanto, o desempenho mostra-se insatisfatório em relação a longevidade destas restaurações. O objetivo desse estudo observacional transversal retrospectivo foi avaliar as razões que resultaram em falhas das restaurações de resina composta de classe I e II de Black, realizadas por alunos de graduação em Odontologia da Universidade Estadual de Londrina. Os pacientes foram selecionados a partir da pesquisa dos prontuários arquivados no Setor de Triagem da Clínica Odontológica Universitária. As restaurações foram avaliadas por dois avaliadores, cirurgiões-dentistas, calibrados. Os dados coletados foram tabulados e analisados por meio de estatística descritiva, função Cont SE. Das 261 restaurações classes I e II avaliadas, 150 (57,5%) apresentavam-se com necessidade de substituição. As principais causas de falhas das restaurações classes I e II foram: cárie secundária (46,7%), seguido de fratura (19,3%) e perda de integridade marginal (16,7%). Dentre as restaurações realizadas por alunos da 3ª série e avaliadas, 68,4% falharam, da 4ª série 57,4% e da 5ª série 53,9%. Com base nos resultados, conclui-se que as principais razões de falha das restaurações foram cárie secundária, fratura e perda de integridade marginal, de acordo com os critérios de avaliação. As restaurações realizadas por alunos da 3ª série apresentaram maior percentual de falhas, comparadas as realizadas pelos alunos da 4ª e 5ª séries. Palavras-chave: Restauração Dentária Permanente. Resinas Compostas. Falha de Restauração Dentária.

Yasir Alnakib,1 Ammar Alsaady2 1Department of conservative Dentistry, Faculty of Dentistry, University of Al-Ameed, Karbala, Iraq; 2Department of Conservative Dentistry, College of Dentistry, Mustansiriya University, Baghdad, IraqCorrespondence: Yasir Alnakib 164/42 Almokhayam District, Karbala, 56001, IraqTel +9647702784555Email yasir.alnakib@gmail.comObjective: To evaluate the effects of the type of ceramic, and the influence of the type of cervical substrate on the microleakage of aged Porcelain laminate veneers (PLVs).Materials and Methods: A total of 48 sound human maxillary premolars were divided randomly into two groups (n=24), Group A: lithium disilicate PLVs; Group B: zirconia reinforced lithium silicate PLVs. The groups were further subdivided into four subgroups (n=12): (A1, B1): finishing line placed in Class V composite filling; (A2, B2): finishing line placed in sound enamel. In subgroups A1 and B1 standardized Class V cavities were prepared and restored with nanocomposite. Standardized PLVs tooth preparation was done for the specimens in all subgroups. Cementation of PLVs was done with a light cured resin cement and specimens were stored in distilled water for 2 weeks. Mechanical load cycling (45,000 cycle, 49 N at 2.5 Hz) and thermocycling procedure (500 cycles, 5– 55°C) were done. A microleakage test was done with dye penetration (2% methylene blue) and the microleakage percentage was recorded and calculated using a stereomicroscope and ImageJ program.Results: Means of microleakage percentage of the subgroups were: A1 (6.6075%), A2 (4.6058%), B1 (7.3158%), and B2 (6.105%), Two-way ANOVA showed a significant effect of ceramic type and cervical composite substrate. According to samples t-test, subgroup A2 was significantly lower than A1 and B2, while subgroup B2 was significantly lower than B1. A P-value≤ 0.05 was considered as statistically significant.Conclusion: The type of ceramic and the type of substrate both affects PLV microleakage. Lithium disilicate PLVs had significantly lower microleakage compared to zirconia reinforced lithium silicate PLVs. Teeth with cervical composite substrate had a significantly higher microleakage compared to teeth with enamel substrate.Keywords: dental leakage, dental restoration, dental veneers, VITA Suprinity, IPS e.max CAD

The purpose of this study is to evaluate the mechanical properties and clinical fitness of 3D-printed bioglass porcelain fused to metal (PFM) dental crowns. To evaluate the mechanical properties, tensile strength, Vickers microhardness, shear bond strength, and surface roughness tests of the SLM printed Co-Cr alloy was conducted. A right mandibular 1st molar tooth was prepared for a single dental crown (n = 10). For a three-unit metal crown and bridge, the right mandibular first premolar and first molar were prepared. Bioglass porcelain was fired to fabricate PFM dental restorations. A clinical gap was observed and measured during each of the four times porcelain was fired. A statistical analysis was conducted. The SLM technique showed the largest statistically significant tensile strength and a 0.2% yield strength value. The milling technique had the lowest statistically significant compressive strength value. The shear bond strength and surface roughness showed no statistically significant difference between the fabricated method. There was a statistically significant change in marginal discrepancy according to the porcelain firing step. The casting technique showed the greatest statistically significant margin discrepancy value. The SLM method showed better fitness than the traditional casting method and showed better mechanical properties as a dental material.

The aim of this clinical study was to evaluate the impact of an additional use of a flowable composite on the clinical success of Class I and II composite restorations. Furthermore, different clinical criteria were recorded to determine if the combination with a flowable material shows significant advantages compared to the composite material alone. In 50 patients, one cavity was solely filled with a nano-hybrid composite (control group) and the second cavity in combination with an additional layer of flowable composite (test group) using a universal adhesive system in the self-etch modus. Clinical assessments were performed according to the modified criteria proposed by USPHS/Ryge. After 24 months, 47 patients were examined resulting in a recall rate of 94%. The cumulative survival rate for all restorations after 24 months was 96.8%. Three restorations (3.2%) failed due to the loss of vitality. All failed restorations were located in the test group (6.4%), and none in the control group (0%). This resulted in a cumulative success rate in the control group of 100% and 93.6% in the test group, showing a significantly different annual failure rate (AFR) of 0% and 3.2%, respectively (p < 0.05; Mann–Whitney U-test). Beside the differences regarding the tooth vitality, success rate, and AFR, no significant influence of the flowable composite on the different evaluated clinical parameters could be detected. Therefore, the application of an additional layer of the flowable composite might have neither a positive nor a negative effect on composite restorations in clinical practice.

Statement of problem The selection of an appropriate restorative material based on fracture behavior is important for the marginal integrity of a dental restoration. For computer-aided design and computer-aided manufacturing (CAD-CAM) restorative materials, information regarding their edge chipping resistance is scarce. Purpose The purpose of this in vitro study was to determine the edge chipping resistance (ECR) and Martens hardness (HM) of 6 different dental CAD-CAM restorative materials before and after thermocycling. Material and methods Four composite resin materials including Brilliant Crios; Cerasmart, an experimental material; Lava Ultimate, a polymer-infiltrated ceramic-network (PICN) material (VITA Enamic), and a glass-ceramic control (IPS Empress CAD) were tested. The specimens were tested before and after thermocycling (30 000 times, 5 °C/55 °C). The ECR was measured for each material (n=25) and related to the point of loading and to the maximum chipping depth. HM was determined for each material (n=25). The Kruskal-Wallis and Mann-Whitney U tests were used to compare materials (α=.05). The impact of thermocycling was analyzed by using the Wilcoxon test (α=.05). The correlations between all parameters were calculated by using the Spearman-Rho test (α=.05). For fractographic analysis of chip patterns, chipped surfaces were analyzed by laser scanning microscopy. Results For ECR and HM, the materials showed different values. ECRmd and ECRpl showed a positive correlation, but both showed a negative correlation to HM. The materials showed a different chip size (P Conclusions All tested CAD-CAM materials behaved as brittle materials, but HM and ECR differed among the materials. The control glass-ceramic material showed the highest values for HM, followed by the PICN material. ECR values revealed the opposite order of materials, with the highest for composite resins. Artificial aging by thermocycling affected all dental CAD-CAM restorative materials. Especially for composite resin materials, ECR changed after aging.

Restorative material is a class of dental materials used for direct filling and fabrication of indirect restoration. NiCr alloy is a restorative material frequently used for dental prostheses due to its properties and economic reasons. In present work beryllium free NiCrMo alloy was developed and studied for dental restoration application. The alloy have unique characteristics of resistance to oxidation and biocompatibility; the requisites for dental prostheses. NiCrMo alloy is found to possess mechanical strength and fabrication properties suitable for dental repairs. In this study the developed alloy was tested for its mechanical properties, biocompatibility and corrosion resistance. An in-vitro biocompatibility study was carried out. No signs of toxicity and no signs of cell growth inhibition, in presence of NiCrMo alloy specimen, were observed. Mechanical properties and corrosion resistance are found in the range that is suitable for dental prostheses and easy fabrication.

Clinically, the use of photo-activated polymer-based dental composites is the preferred method to restore carious teeth due to their esthetics and ease of application. However, the longevity of these resin-based composite tooth restorations can be compromised by the sensitivity of the bonded interface between the composite and the tooth surface. The objective of the current study was to modify the tooth surface with novel fluorinated polyphosphazenes (PPZs), thereby improving the stability of the interface. Binding isotherms of PPZs with collagen (CLG) and hydroxyapatite (HA), two of the primary components of teeth, were established and indicate significant and stable adsorption to the surfaces of these materials. PPZs were also shown to protect CLG against acidic dissolution in a model system. A composite material consisting of the fluorinated polymer and CLG demonstrated three-dimensional stability and significant hydrophobicity. Additionally, no hemolytic activity was observed when evaluated using a porcine red blood cells (RBC) assay. Bovine dentin treated with PPZs demonstrated increased contact angle (hydrophobicity) compared with control samples and resisted fluid penetration when assessed using a dye penetration study. Finally, microhardness evaluation of bovine dentin treated with PPZs and exposed to an acidic challenge showed that treated dentin resisted demineralization. The hardness of the untreated control was significantly reduced after exposure when compared with the PPZ-treated samples. This study represents a novel approach to overcoming the current limitations of composite restorations. These results are promising to improve the longevity of composite dental restorations and may have wider use in sealants, varnishes, and other dental applications. Tooth decay remains a prevalent problem worldwide. Polymer-based composites are the most frequently used tooth restorative used in the clinic. The longevity of these fillings is limited due to conditions in the mouth that can weaken the adhesive used to bond the composite to the natural tooth. The current study uses novel polyphosphazenes (PPZs), hybrid organic-inorganic macromolecules with tunable hydrophilic-hydrophobic properties to coat the tooth surface to achieve better compatibility with the adhesive, thereby improving the longevity of the restoration. Results indicate that PPZs have significant and stable adsorption onto teeth, which may lead to a more stable bonded interface.

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.