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Objectives: To evaluate the fracture resistance (FR) of polyetheretherketone (PEEK) abutments produced by additive and subtractive methods compared to milled zirconia abutments., Methods: Custom abutments were designed on Ti-base abutments and produced from three different materials, namely additively manufactured PEEK (PEEK-AM), subtractively manufactured PEEK (PEEK-SM), and zirconia (N = 60). PEEK-AM abutments were printed using PEEK filaments (VESTAKEEP®i4 3DF-T, Evonik Industries AG) on a M150 Medical 3D Printer (ORION AM) by fused filament fabrication (FFF). All surface treatments were carried out according to the manufacturer's instructions. All abutments were cemented on Ti-bases with hybrid abutment cement and then restored with milled zirconia crowns. Each subgroup was divided into non-aged and aged subgroups (n = 10). The aged groups were subjected to thermomechanical aging (49 N, 5-55 °C, 1.2 million cycles). FR tests were performed by using an universal testing machine. Data were statistically analyzed with one-way and two-way ANOVA and t-test., Results: The survival rate of the specimens after aging was determined as 100%. It was found that both the material and aging had a significant effect on the FR (p<.001). There was a statistical difference among the fracture values of the groups (p<.001). In both the aged and non-aged groups, PEEK-AM showed the statistically lowest FR, while the highest FR was seen in the zirconia group, which was significantly higher than the PEEK-SM (p<.001)., Conclusion: Hybrid abutments were successfully manufactured, and extrusion-based processed PEEK seems to be a good alternative to subtractive processed PEEK. However, since subtractive manufacturing still appears to be superior, further developments in additive manufacturing are needed to further improve the quality of 3D-printed PEEK parts, especially in terms of accuracy and bonding between adjacent layers., Clinical Significance: Additively manufactured PEEK abutments have the potential to be an alternative for implant-supported restorations in the posterior region., Competing Interests: Declaration of competing interest All other authors have no conflicts of interest to declare. The authors do not have any financial interest in the companies whose materials are included in this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: The objective of this review was to assess clinical trials that have examined the materials, design, and bonding of ceramic cantilevered resin-bonded fixed dental prostheses (RBFDPs) as a potential option for replacing missing anterior teeth. The evaluation primarily focuses on the rate of restoration failure and clinical complications., Materials and Methods: A thorough search of databases including PubMed/MEDLINE, Scopus, and the Cochrane Library, was conducted. The most recent search was performed in October 2023. Clinical studies that compared ceramic cantilevered RBFDPs with double retainers or cantilevered RBFDPs using different ceramic materials or bonding systems were included. The outcome measures considered were restoration failure and complication rates., Results: Twelve studies met the eligibility criteria. The pooled data showed a statistically significant decrease in complication events when using cantilever designs compared with double retainer designs (p < 0.05); however, there were no differences found between the two designs in terms of restoration failure. The complication and failure rate of cantilever RBFDPs did not show a statistically significant difference with or without ceramic primer application before luting with phosphate monomer-containing luting resin (p > 0.05)., Conclusions: Ceramic cantilevered RBFDPs have lower complication rates compared with those with double retainers. The use of a ceramic primer prior to luting composite resin for ceramic cantilevered RBFDPs decreases the occurrence of complications and failures, although this effect was not statistically significant. Additional research is required to confirm these findings. Glass ceramic cantilever RBFDPs showed a decrease in success after 6 years, requiring ongoing monitoring, but both zirconia and glass-infiltrated alumina cantilever RBFDPs have demonstrated durability with excellent long-term success and survival rates for up to 10 and 15 years., Clinical Significance: Cantilever ceramic RBFDPs in the anterior region are a less invasive and valuable treatment option, providing good esthetic results., (© 2024 Wiley Periodicals LLC.)

Background: Occlusal veneer had been evaluated for mechanical properties using lithium disillicate. However, studies evaluating the mechanical properties of occlusal veneer with different preparation designs and ceramic materials are lacking. So, this in vitro study aimed to evaluate the fracture resistance of occlusal veneers with two designs fabricated from two different ceramic materials., Material and Methods: Fourty mandibular third molars were distributed to 2 groups (n = 20) according to preparation design: group (O) anatomical occlusal reduction and group (OA) anatomical occlusal and 1 mm axial reduction. Each group was additionally subdivided into two subgroups (n = 10) according to ceramic materials; in subgroup X, lithium disilicate (e.max CAD, Ivoclar AG, Schaan, Liechtenstein) was used, and in subgroup S, zirconia-reinforced lithium silicate (ZLS) (Vita Suprinity, VitaZahnfabrik, Bad Säckingen, Germany) was used. All specimens were cemented with a light-cure resin cement (Choice 2, Bisco, Schaumburg, USA). 5000 thermocycles were applied to all specimens with both temperatures of 5 °C and 55 °C in two water baths; the dwell time was 30s at each bath, and the transfer time was 10s. Then all specimens were subjected to a fatigue simulation under dynamic loading of 200 N for 250,000 cycles. A universal testing machine (5500R/1123, Instron, Norwood, USA) was used to evaluate the fracture strength with a crosshead speed of 1 mm/min. All data were analyzed statistically by using a two-way ANOVA, and for some violations of assumptions, these results were compared with those obtained by the nonparametric test (Scheirer Ray Hare) (α = 0.05)., Results: A statistically significantly higher fracture resistance in the 'OA' (3389 N) compared to the 'O' (2787 N) group regardless of the ceramic material (P < .001) and a statistically significantly higher fracture resistance in the 'X' (3295 N) compared to the 'S' (2881 N) regardless of the preparation design (P = .015)., Conclusions: For occlusal veneers, all preparation designs and materials (such as Vita Suprinity and e.max CAD) had clinically acceptable fracture resistance values that were greater than the maximal biting forces. On the other hand, the e.max CAD with occlusal veneer, including axial reduction design, demonstrated the maximum fracture resistance value. Finally, no relationship between fracture strength and mode of failure was found., (© 2024. The Author(s).)

Background: Two intra-coronal preparation designs with varying extensions of cuspal coverage can perform differently regarding their fracture resistance against introral forces., Methods: Two materials (IPS e-max CAD [EX], VITA ENAMIC [EN]), and two different preparation designs (EX-D1), (EX-D2), (EN-D1), and (EN-D2) were investigated to compare their fracture resistance. A total of 40 (n = 40) caries free human mandibular molars were used. All the prepared samples were scanned using CEREC Omnicam scanner and the preparations were checked by the software for any sharpness and undercuts before restoration designing and fabrication. All restorations were milled using Cerec MCXL 4.4 milling machine. Duo-Link resin cement was used for cementation. After thermocycling and chewing simulation, all samples were loaded in the Universal testing machine in order to evaluate fracture resistance of all samples., Results: Fracture resistance testing revealed that e-max CAD (2134 N) showed statistically significantly higher mean fracture resistance values than Vita Enamic (1728 N). On the other hand, there was no statistically significant difference between mean fracture resistances between the two tested designs., Conclusions: Within the confines of this investigation, it can be said that although preparation design had no appreciable impact on fracture resistance, the CAD/CAM ceramic material utilized did., Clinical Significance: When restoring compound cavitties indirectly; a conservative defect oriented approach should be used. Glass Ceramic are prefered as restorative material., (© 2024 Wiley Periodicals LLC.)

Introduction: The effect of antiplatelet and anticoagulant medications on the outcomes of sinus floor augmentation remains unclear., Methods: This retrospective cohort study analyzed data from electronic medical records of consecutive patients undergoing sinus floor augmentation at a single medical center. Patients were categorized into three categories: patients under antiplatelet medications, patients under anticoagulation medications, and healthy individuals. Data collected included tobacco smoking, residual alveolar bone height, timing of implant placement, materials used, vertical bone gain, early implant failure (EIF), and complications such as Schneiderian membrane perforation and postoperative bleeding. Multivariable analysis was performed to assess risk factors for EIF. Statistical significance was considered below 5%., Results: Among 110 patients with 305 implants, EIF occurred in 10% of patients and 4.65% of implants. No significant difference in postoperative bleeding or EIF was found between study groups. Univariate and multivariable analyses highlighted tobacco smoking (odds ratio [OR] = 7.92), lower residual alveolar ridge height (OR = 0.81), and staged implant placement (OR = 4.64) as significant EIF risk factors in this cohort., Conclusions: Anticoagulant and antiplatelet therapies do not significantly elevate the risk of EIF or postoperative bleeding following sinus floor augmentation. Tobacco smoking, residual alveolar ridge height and staged sinus floor augmentation were risk factors for EIF in patients using antiplatelet or anticoagulation medications undergoing sinus floor augmentation., (© 2024 The Author(s). Clinical Implant Dentistry and Related Research published by Wiley Periodicals LLC.)

Clinicians who place and restore implants are always concerned about the success and longevity of the same. There are several local and systemic factors that affect osseointegration and the health of the peri-implant tissues. In this study, we review the systemic factors that can affect implant survival, osseointegration, and long-term success. The study highlights the importance of delineating, and taking into consideration these systemic factors from the planning phase to the restorative phase of dental implants. A thorough medical history, including prescription and over-the-counter medications, is vital, as there may be numerous factors that could directly or indirectly influence the prognosis of dental implants., Competing Interests: Disclosure D. C. Thomas, D. Bellani, J. Piermatti, and P. Kodaganallur Pitchumani declare no conflict of interest. There was no funding for this study. Statement of institutional review board approval or waiver: Institutional review and approval were not necessary for this study., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: Endocrowns can be fabricated from various materials as a treatment option for endodontically treated teeth. This mixed cohort study aimed to demonstrate the clinical efficacy of Endocrowns made of feldspathic, zirconia lithium silicate, and lithium disilicate ceramics using a chairside CAD/CAM system., Methods: The present study compared the clinical outcomes of 141 Endocrown restorations in posterior teeth of 85 patients in a two-year follow-up. The efficacy of restorations was evaluated in three aspects: esthetics, biological response, and function, with the aid of the FDI guideline, and presented as descriptive analyses. Additionally, the data were analyzed using Chi-square and Spearman correlation tests. The significance level was set at p = 0.05., Results: The study findings revealed that the type of restorations (feldspathic ceramic, zirconia lithium silicate, and lithium disilicate) (p > 0.05) and underlying teeth (molars and premolars) (p > 0.05) play no part in restorations' failure. Caries' recurrence is primarily responsible for the failure of the endocrowns. Secondary caries and radiolucency were observed in four teeth (2.83 %). The clinical efficacy of 126 restorations (89.36 %) fell into the category of "clinically excellent" and "clinically good." Ten restorations (7.09 %) were classified as "clinically sufficient/satisfactory," and only five restorations (3.54 %) needed replacement due to having "clinically unsatisfactory" and "clinically poor" quality., Conclusions: Endocrowns showed a high success rate and durability in the short term, therefore can be considered a safe choice for restoring endodontically treated teeth. It is worth noting that caries were the most common reason for the failure of the restorations., Clinical Significance: Endocrowns made of different ceramics have been proven reliable restorations for endodontically treated molars and premolars., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Broken screw removal from the implant connection is a common but challenging process. Several proposed methods and technical solutions may result in unsuccessful removal; thus, a novel, more conservative, risk-free method is proposed as a first attempt. The proposal is to use a silicon restoration holder to be twisted counterclockwise on the dried surface of the broken fragment inside the implant connection. This method, within the limitations of a minimal case series, yielded 100% results; however, despite previous attempts with less conservative techniques, this approach showed no efficacy. This article aims to promote the use of silicon restoration holders as a minimally invasive first attempt at broken screw retrieval treatment before considering other options.

Objective: This study aimed to determine the survival of class II composite restorations in premolars and molars with and without base bulk-fill composite in general dental practice., Materials and Methods: We collected data from the electronic patient files of the Public Dental Services in the City of Oulu, Finland. The timespan of data collection was from August 15th, 2002, to August 9th, 2018. The data consisted of class II composite restorations both with and without base bulk-fill composite. We compared the survival of these restorations using Kaplan-Meier survival curves, the log-rank test, survival rates, and the Wilcoxon signed ranks test., Results: We observed 297 restorations in 96 patients. The five-year survival rates for restorations with and without base bulk-fill composite were comparable in premolars (77.5% and 77.4%, respectively) but different in molars (69.9% and 57.8%, respectively, p = 0.069). In molars, the restorations with base bulk-fill composite exhibited a higher survival rate in 14 patients, whereas in 11 patients the restorations without base bulk-fill composites exhibited a higher survival rate. In 24 patients the survival rates were similar for restorations with and without the base bulk-fill composite (p = 0.246)., Conclusions: The restorations with and without base bulk-fill composite had similar longevity., Clinical Relevance: Base bulk-fill composites are safe to use in general practice due to their similar survival rates compared to conventional composites., (© 2024. The Author(s).)

The purpose of this study was to investigate the fracture behavior of endodontically treated (ET) deciduous molar when directly restored with different restorative materials in Class II (MO) cavities in comparison with permanent teeth. MO cavities were prepared with 2.4-2.5 mm and 1.9-2.0 mm in buccolingual width, and mesiodistal width of each cavity walls, respectively, followed by direct restoration with different materials: resin-modified glass ionomer cement (RMGIC), composite resin (CR), and composite resin containing 25% short glass-fiber (SFRC). All specimens were subjected to mechanical loading tests at a speed of 1 mm/min and evaluated fracture resistance and fracture modes. A one-way ANOVA followed by a Tukey multiple comparisons analysis was used. Deciduous-SFRC (3,310.5±396.2 N) were significantly higher fracture resistance than permanent-RMGIC (1,633.8±346.8 N) (p<0.001), and permanent-CR (1,400.0±381.3 N) (p<0.001). For the direct restoration of MO cavity after endodontic treatment, SFRC demonstrated its promising performance in load-bearing capacity and failure mode, especially in ET deciduous molars.

This study evaluated fracture resistance of monolithic fixed dental prostheses (FDPs) fabricated using different placement strategies of various connector designs in multilayered zirconia disc. Monolithic FDPs were placed in translucent and dentin layers of multilayered zirconia disc and fabricated with V-shaped and U-shaped connector designs gained by sharp and blunt millings. The FDPs were cemented on abutment models made of polymer material, underwent thermal cycles, and loaded to fracture using the universal testing machine. Fracture loads and modes were analyzed using two-way ANOVA, Tukey's post hoc test, and Fisher exact test (p≤0.05). The chosen placement strategy and connector designs gained by different milling procedures in computer-aided design/computer-aided manufacturing technology affect fracture resistance of monolithic FDPs made of multilayered zirconia materials. Placing the connector in translucent layer rather than dentin layer of multilayered zirconia disc and using sharp milling significantly reduces fracture resistance of monolithic multilayered zirconia FDPs.

Purpose: To evaluate the behavior of hybrid abutment crowns fabricated from monolithic lithium disilicate ceramic (LDC) and to compare the influence of different in vitro artificial aging protocols., Materials and Methods: A total of 32 monolithic hybrid abutment crowns of monolithic LDC were fabricated. Of these, 24 were artificially aged using three different protocols up to a 20 year simulation (1.2 × 106, 2.4 × 106, 4.8 × 106 chewing cycles, thermocycling), a control group underwent no artificial aging (n &#61; 8, N &#61; 32). Load-to-failure tests were conducted for all specimens, and failure values were compared (P < .05)., Results: All specimens passed in vitro aging. Mean failure load values between 532.6 and 562.8 N were found but did neither differ significantly among the test groups nor from the control group., Conclusions: Within the limitations of this in vitro pilot study, hybrid abutment crowns manufactured from monolithic LDC seem to offer appropriate long-lasting mechanical stability over a simulation period up to 20 years. The failure values and complication pattern seem to be independent of several aging protocols in this test set-up.

Objective: This meta-analysis aims to investigate the long-term survival rates of dental implants over a 20-year period, providing a practical guide for clinicians while identifying potential areas for future research., Materials and Methods: Data were sourced from recent publications, focusing exclusively on screw-shaped titanium implants with a rough surface. Both retrospective and prospective studies were included to ensure an adequate sample size. A systematic electronic literature search was conducted in the databases: MEDLINE (PubMed), Cochrane, and Web of Science. The risk of bias for all studies was analyzed using a tool by Hoy et al. RESULTS: Three prospective studies (n = 237 implants) revealed a mean implant survival rate of 92% (95% CI: 82% to 97%), decreasing to 78% (95% CI: 74%-82%) after imputation (n = 422 implants). A total of five retrospective studies (n = 1440 implants) showed a survival rate of 88% (95% CI: 78%-94%). Implant failure causes were multifactorial., Conclusion: This review consolidates 20-year dental implant survival data, reflecting a remarkable 4 out of 5 implants success rate. It emphasizes the need for long-term follow-up care, addressing multifactorial implant failure. Prioritizing quality standards is crucial to prevent overestimating treatment effectiveness due to potential statistical errors. While dental implantology boasts reliable therapies, there is still room for improvement, and additional high-quality studies are needed, particularly to evaluate implant success., Clinical Relevance: Never before have the implant survival over 20 years been systematically analyzed in a meta-analysis. Although a long-term survival can be expected, follow-up is essential and shouldn't end after insertion or even after 10 years., (© 2024. The Author(s).)

To evaluate the fracture load of bilayer ceramic crowns manufactured by Rapid Layer Technology (RLT) after different cementation protocols of the veneering ceramic to the zirconia infrastructures. Sixty epoxy resin preparations simulating a molar tooth were obtained and 60 zirconia infrastructures and feldspathic crowns were manufactured by RLT and divided into 6 groups according to the cementation protocol at the interface to veneering ceramic (n=10): Ctr- control: conventional resin cement; Al- Al2O3 sandblasting 50µm + conventional resin cement; Al/MDP- Al2O3 sandblasting (50µm) + resin cement with MDP; Sil- silicatization 30µm + conventional resin cement; Gl/HF- glaze + hydrofluoridric acid (5%,60s) + silane + conventional resin cement; Gl- glazing as bonding agent. The feldspathic ceramic internal surface was etched with fluoridric acid (5%) + silane followed by cementation according to respective protocols. All samples were mechanically cycled (200N and 4.5x105 Pa, 37°C, 2x106 cycles, 3.4Hz) and submitted to axial compressing fracture load test (10kN, 0.5mm/min). The results(N) were submitted to descriptive and analytical statistical analysis with 1-way ANOVA, Weibull, and the Tukey test (α=0.05). ANOVA revealed that there was a significant difference among the tested groups (p<0.0001). The group Al/MDP presented the higher resistance to fracture (1972.46A N), followed by the Ctr group (1584.41B N). The characteristic strength(σ0) was significantly different (p=0.000). The crack and chipping were the predominant failures. The air-abrasion at the external surface of zirconia with Al2O3 followed by cementation with MDP resin cement, should be selected to Rapid Layer Technique when felspathic ceramic is used as veneer ceramic.

This study aimed to assess the fatigue resistance of molars lacking a coronary remnant, using zero, one, two, or three fiberglass posts. Forty caries/crack-free human molars with coronal portions removed at the pulp chamber floor were randomly allocated into four groups (n=10). Following endodontic treatment, posts (Whitepost DC/DC.E 0.5, 1.0, FGM) were silanized (silane agent, Angelus) and cemented with a resin cement (RelyX U200, 3M ESPE). Resin composite cores (Z350, 3M ESPE) were built, and metal crowns were fabricated and cemented using the same luting system. Samples underwent cyclic fatigue testing at 45°, applying load in the occlusal surface at 10 Hz and 100 N initial load for 10,000 cycles, with 50 N increments every 10,000 cycles until failure. Fatigue failure load and cycles for failure data were recorded and subjected to survival analysis through Kaplan-Meier and Mantel-Cox post hoc tests, and Weibull analysis. Fractography patterns of failed crowns were qualitatively analyzed. The group without posts exhibited the lowest fatigue performance (p < 0.05) for both fatigue failure load and cycles to failure. Superior fatigue performance was observed in the three-post group, followed by groups with one or two posts, corroborated by the Weibull characteristic strength parameter. Weibull moduli were similar among conditions. All specimens exhibited failure involving detachment of the restorative set (posts/core/crown) with a portion of the dental remnant, without tooth fracture. Thus, when restoring mandibular molars without crown remnants, the use of fiberglass posts promotes greater fatigue resistance to oblique loads.

Background: Partial coverage concepts have met the main goal of conservative dentistry. Vonlays, which combine features of veneers and onlays, are a recent alternative to full coverage designs and overlay partial coverage restorations. This in vitro study was conducted to compare the fracture resistance of the newly introduced pressable zirconia-reinforced lithium silicate with pressable lithium disilicate ceramic and to determine the optimal preparation design for partial coverage on upper premolars., Methods: Fifty-two duplicated epoxy resin dies were prepared following vonlay and overlay preparation guidelines. For each preparation (n = 26), the specimens were divided into two subgroups to be restored with lithium disilicate (IPS e.max Press) or zirconia-reinforced lithium silicate (Vita Ambria) (n = 13 each). Ceramic vonlays and overlays were bonded using dual cure resin cement, subjected to thermomechanical fatigue, and the load to fracture was tested by using a universal testing machine. The specimens were fractographically analyzed via scanning electron microscopy (SEM). The normality of the fracture resistance data was checked using the Shapiro‒Wilk test and Q‒Q plots, and two-way ANOVA was used to assess the effect of the type of preparation and ceramic material on the fracture resistance., Results: The group of overlays restored with zirconia-reinforced lithium silicate showed the highest mean fracture load (1218.69 N), while the group of vonlays restored with lithium disilicate had the lowest mean fracture resistance (967.15 N). The effect of preparation design and material type on fracture resistance was significant for both factors, p = 0.003 and p < 0.0001, respectively. Different features of the fracture surfaces, such as arrest lines, hackles, and directions of crack propagation, were observed., Conclusions: Zirconia-reinforced lithium silicate exhibited greater resistance to fracture compared to lithium disilicate, making it a potential substitute for partial coverage restorations. Additionally, the overlay showed superior fracture resistance when compared to the vonlay preparation design., (© 2024. The Author(s).)

Background: Recently, prosthodontic approaches involve more conservative procedures that include less invasive finish line preparations that use less ceramic thickness., Aim of the Study: This in vitro study aimed to evaluate the effect of vertical preparation and modified vertical preparation designs on the marginal adaptation and fracture resistance of two types of ceramic crowns using CAD/CAM technology., Materials and Methods: Two typodont maxillary first premolars were embedded in acrylic resin. Forty positive replicas of epoxy resin dies were used that were divided into two groups depending on the preparation design (n = 20); Group V (Vertical): dies with feather edge finish line and Group MV (Modified vertical): dies with feather edge finish line, where a reverse shoulder of 1 mm depth was placed on the buccal surface 1.5 mm from the occlusal surface. Each group was further subdivided into two subgroups according to the type of ceramic material (n = 10): Subgroup Va and subgroup MVa for lithium disilicate (e.max CAD) and subgroup Vb and subgroup MVb for zirconia (zolid ht+). Crown restorations were made with CAD-CAM technology. The marginal adaptation was assessed using a stereomicroscope both prior to cementation and after cementation and aging. Fracture resistance was tested with a universal testing machine, and the data were statistically analyzed., Results: Marginal adaptation showed no significant differences between subgroups before or after cementation and aging. Three-way ANOVA indicated that preparation design (p = 0.516) and material (p = 0.269) had no significant effect, but cementation had a significant effect (p < 0.0001) on the marginal adaptation. According to two-way ANOVA test, Subgroup (MVb) showed the highest result followed by subgroup (Vb) and subgroub (MVa) and the least was subgroub (Va). Fracture modes showed no significant differences among the subgroups (p = 0.982)., Conclusions: Marginal adaptation of lithium disilicate and zirconia crowns remained clinically acceptable regardless of preparation design. While the modified vertical preparation with a reverse shoulder notably enhanced the fracture resistance of both materials, with zirconia demonstrating superior fracture resistance compared to lithium disilicate with average values exceeding premolar biting force., (© 2024. The Author(s).)

Dental implant restoration shows an effective method for the rehabilitation of missing teeth. The failure rate of periodontal implants in patients with chronic periodontitis is associated with periodontal flora, inflammation, and long-term periodontal bone resorption caused by chronic periodontitis. However, the therapeutic effects of dental implant restoration on inflammation in patients with chronic periodontitis have not addressed. The purpose of this study is to evaluate the risk indicators for inflammation, bone loss and implant failure in patients with chronic periodontitis. A total of 284 patients with dental implant restoration were recruited and divided into periodontally healthy patients (n = 128) and chronic periodontitis patients (n = 156). Periodontal indices including probing depth (PD), sulcus bleeding index (SBI), plaque index (PLI), gingival bleeding (GIL) and bleeding on probing (BOP) were compared in two groups. Inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 (IL-1), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) levels at baseline, 6 and 12 months after surgery, and the implant survival rate at 12 months after surgery, as well as the risk factors associated with failure of dental implant were also assessed. Outcomes demonstrated that patients in the chronic periodontitis group had higher values of periodontal indices than those in the periodontally healthy group. All inflammatory parameters in the chronic periodontitis group were higher than those in the periodontally healthy group and negatively associated with the chronic periodontal index (CPI) in chronic periodontitis patients. Chronic periodontitis patients had higher the prevalence of mucositis and peri-implantitis than patients with healthy periodontium. Implant diameter, length and design was associated with the risk of implant failure for chronic periodontitis patients receiving dental implant. The cumulative implant failure rate and incidence of implant fractures for chronic periodontitis patients at 12 months after surgery were 12.10% and 7.23% (p < 0.05), respectively, while were lower in the heathy periodontitis patients. Location, diameter, implant design, immediate loading and bone defect were risk indicators for bone loss for dental implant patients. The risk factors associated with failure of dental implant was higher in chronic periodontitis patients than patients in the periodontally healthy group (14.25% vs. 4.92%, p < 0.05). In conclusion, data in the current study indicate that inflammation is a risk indicator bone loss, implant fracture and implant failure in patients with chronic periodontitis., (© 2024. The Author(s).)

In recent years, a wide variety of materials have been used in dental implant treatment. In selecting the superstructures and abutments to be used it is important to consider their potential effect on the stability and durability of the planned implant. Excessive force applied to an implant during maintenance commonly results in complications, such as fracture of the superstructure or abutment, and loosening or fracture of the screws. This report describes a case of implant treatment for a 23-year-old man with esthetic disturbance due to trauma to the maxillary anterior teeth. The left maxillary central incisor could not be conserved due to this trauma, which had been caused by a traffic accident. After extraction, the tooth was restored with an anterior bridge. The crown of the left maxillary lateral incisor was fractured at the crown margin and, at the patient's request, implant treatment was selected as the restorative treatment for the missing tooth. A thorough preoperative examination was performed using placement simulation software. One titanium screw-type implant was placed in the maxillary left central incisor under local anesthesia. An all-ceramic crown with a zirconia frame was placed as a screw-fixed direct superstructure. At one year postoperatively, however, the superstructure and abutment became detached due to trauma. The fractured zirconia abutment was removed and replaced with a remanufactured abutment and superstructure. The patient has reported no subsequent dental complaint over the last 11 years. In this case, a surface analysis of the fractured zirconia abutment was performed. The scanned images revealed a difference in the fracture surfaces between the tensile and compressive sides, and electron probe microanalysis demonstrated the presence of titanium on the fracture surface. It was inferred that the hard zirconia abutment had scraped the titanium from the internal surface of the implant.

Purpose: The present study evaluated osteopenia (OPN) and osteoporosis (OP) as risk factors for dental implant failure and repeat failure., Methods: We performed a retrospective study on over 100 randomly selected patients per analysis to determine the effect of health status, smoking status, sex, implant location and operative conditions on first and second (re-implantation) implant survival. Analyses were conducted first using chi-squared test, followed by multiple logistic regression for significant variables., Results: In the cohort examining the effect of myriad risk factors on second implant survival, it was found that OPN and OP greatly impacted implant survival, wherein patients with osteoporosis or osteopenia had significantly more implant failures (p = 0.0353). Sex and operative conditions had no effect on implant survival, while implant location showed a notable effect wherein significantly more failures occurred in the maxilla vs mandible (p = 0.0299). Upon finding that OPN and OP have a significant effect on second implant survival, we conducted an additional study focusing on the impact of health status. Based on the multiple logistical regression analysis, we found that OPN and OP are the most significant factor in first implant survival (p = 0.0065), followed by diabetes (p = 0.0297). Importantly, it was observed that early implant failure is also significantly correlated with osteoporosis (p = 0.0044)., Conclusion: We show here a marked relationship in which the risk of first and second implant failure are significantly higher in patients with osteoporosis and osteopenia., (© 2024. The Author(s).)

Aim: Dental caries is a common oral disease in children with special needs such as those with autism spectrum disorders (ASDs). The aim is to assess whether the type and survival of three caries management, conventional resin restorations (CR), ART technique (ART) and SDF application without caries removal (SDF), in primary teeth carried out at the Pediatric Dentistry Department of San Paolo Hospital (University of Milan) differed between children with ASDs and unaffected peers., Methods: Data from a convenience sample of children with and without ASDs, who have received dental care for caries in primary teeth from January 2019 to June 2022, were analysed. Medical history, age, sex, teeth treated, and type of treatment were collected from dental charts. Data on success and minor and major failures of each treatment were also collected. Two survival analysis were performed, one considering both major and minor failures, a second considering only major failures. Cox Proportional Hazards multivariate logistic models were run to assess factors associated with failures. The statistical significance was set at 5% (p< 0.05)., Conclusion: In children with autism, the different techniques for approaching caries lesions seem to have the same probability of success. Therefore, the choice of treatment should be patient-oriented rather than lesion-oriented. In unaffected children, the gold standard always seems to be traditional restorative treatment.

Statement of Problem: Few studies have investigated the differences among various post-and-core systems under mastication simulation. Comparing these systems while simulating the clinical environment should provide a more accurate assessment of their performance., Purpose: The purpose of this in vitro study was to evaluate the fatigue resistance of conventional cast metal and prefabricated fiber post systems with computer-aided design and computer-aided manufacture (CAD-CAM) prefabricated nonmetal post-and-core systems., Material and Methods: Forty freshly extracted human maxillary premolars were endodontically treated and divided into 4 subgroups (n=10) according to the material: cast metal, zirconia, fiber-reinforced composite resin, prefabricated fiber post. The post-and-core materials were manufactured either conventionally or milled with CAD-CAM technology. All specimens were exposed to simultaneous mastication simulation (1.2 million cycles) and thermocycling (10 000 cycles at 5 °C to 55 °C) and analyzed based on failure of specimens. Data were analyzed by using the Kaplan-Meier survival analysis and Cox-regression (α=.05)., Results: Both cast metal and zirconia post-and-core groups had similar fatigue resistance (P>.05) but significantly higher fatigue resistance than the fiber-reinforced groups (P<.05). Fiber-reinforced composite resin and prefabricated fiber post did not survive the mastication simulation, fracturing between 504 000 and 752 000 cycles, with fractures occurring in the cervical portion of the tooth., Conclusions: Cast metal and zirconia post-and-core systems had improved physical properties with high resistance to fatigue when compared with fiber-reinforced post-and-core systems., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objectives: To evaluate the survival rates and marginal bone loss of narrow-diameter titanium-zirconium implants supporting complete maxillary and mandibular overdentures up to 3 years after loading., Materials and Methods: Ten completely edentulous patients who were dissatisfied with their complete dentures were enrolled. Two narrow-diameter implants were placed in the canine region of the maxilla and mandible. After second-stage surgery, implant-supported overdentures (palatal-free) attached by parallel alignable stud-attachments were placed. Patients were followed periodically for up to 36 months. Standardized radiographs were taken at baseline, 12 and 36 months to analyze mean marginal bone level changes around the implants., Results: The Kaplan-Meier survival rates were 100% for mandibular and 68.0% (SE ± 10.9%) for maxillary implants at 36 months (p = .008). Six maxillary implants failed after loading; no mandibular implants were lost. Five implants failed due to loss of osseointegration. One implant fractured. The mean marginal bone level changes around the analyzed implants (n = 28, 9 patients) were -0.71 ± 0.82 mm in the mandible and -2.08 ± 1.52 mm in the maxilla at the 36-month follow-up. The difference in marginal bone level changes between the maxilla and mandible was significant (p = .019) at the 12- and 36-month follow-ups., Conclusion: Two narrow-diameter titanium-zirconium implants with stud-attachments showed a highly satisfactory outcome in the mandible. The maxillary implants showed a high failure rate and significantly more bone loss over time than the mandibular implants. The minimal concept of two implants and an overdenture should be limited to the edentulous mandible., (© 2024 The Author(s). Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Objectives: We assessed the radiation dosages (D mean ) on implant regions to identify the threshold for implant loss in patients with an intraoral malignancy treated with dental implants to support a mandibular denture during ablative surgery before volumetric-modulated arc therapy (VMAT)., Materials and Methods: Data was collected prospectively from 28 patients treated surgically for an intraoral malignancy, followed by postoperative radiotherapy (VMAT) and analyzed retrospectively. Patients received 2 implants in the native mandible during ablative surgery. Implant-specific D mean values were retrieved from the patients' files. Radiographic bone loss was measured 1 year after implant placement and during the last follow-up appointment. Implant survival was analyzed with the Kaplan-Meier method. Univariate logistic regression and Cox-regression analyses were performed to investigate the effect of increasing implant-specific radiation dosages on implant loss., Results: Five out of 56 placed implants were lost during follow-up (median 36.0 months, IQR 39.0). Radiographically, peri-implant bone loss occurred in implants with a D mean  > 40 Gy. Implant loss occurred only in implants with a D mean  > 50 Gy., Conclusion: An implant-specific D mean higher than 50 Gy is related to more peri-implant bone loss and, eventually, implant loss., (© 2023 The Authors. Oral Diseases published by Wiley Periodicals LLC.)

This report of four clinical cases aims to illustrate the use of a lateral implant as a solution for implant overdentures in the mandible in different clinical situations. The first two cases describe the clinical situations of patients wearing two-implant mandibular overdentures until the failure of one of the implants, one due to implant loss and the other due to a fracture of an abutment screw, and how the conditions were managed. The third case illustrates the placement of a single implant to retain an overdenture, where a midline implant, as originally planned, was not feasible due to anatomic reasons. The final case describes the use of a lateral implant to support and retain a single-implant mandibular overdenture. The four cases demonstrate that a single lateral implant can be utilized as sole retention in cases of a failing contra-lateral implant and as an alternative to a single implant in the midline., (© 2024 The Authors. Journal of Prosthodontics published by Wiley Periodicals LLC on behalf of American College of Prosthodontists.)

Purpose: To evaluate the survival rates of dental implants with a hybrid macrostructure and the surface biomimetically coated with nanohydroxyapatite, placed in horizontally atrophic maxillae previously submitted to the guided bone regeneration (GBR) procedure, associated with the use of a deproteinized bovine bone graft (DBB)., Methods: Twenty-five patients who received 196 implants were involved in this study. First, these patients were submitted to GBR procedures and maxillary sinus lift, where DBB was used as the grafting material. The dental implants were placed after a minimum period of 6 months of the grafting procedures. The patients were followed up every six months and clinical/radiographic examinations were performed to assess the implants, using the following indicators as a reference: (1) Absence of mobility; (2) Absence of pain. Data about the age, surgery time, smoking status, implant size, and time between the grafting procedure and implant placement were correlated with implant failures., Results: Twelve implants failed, generating a survival rate of 94.23%. None of the variables analysed correlated with the implant failures., Conclusion: Implants with a hybrid macrostructure and surface biomimetically coated with nanohydroxyapatite present good survival rates in horizontally atrophic maxillae grafted with DBB., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To evaluate the mechanical performance of patient-specific prefabricated temporary shell versus laboratory-fabricated CAD/CAM provisional restorations on titanium temporary abutments, with and without thermo-mechanical ageing., Materials and Methods: Implants with a conical connection were divided into four groups (n = 24) and restored with temporary shell or laboratory-fabricated central or lateral incisor PMMA restorations that were relined or bonded on titanium temporary abutments. The diameter of the central and lateral incisor groups' implants was regular (ϕ 4.3 mm) or narrow (ϕ 3.5 mm), respectively. Half of each group's specimens were subjected to ageing, simultaneous thermocycling (5-55°C) and chewing simulation (120,000 cycles, 50 N, 1.7 Hz) resulting in eight groups in total (n = 12). The aged specimens were evaluated with optical microscopy, and survival and complication rates were determined according to modified USPHS criteria. The non-aged specimens and those that had survived ageing were loaded until failure, whereupon bending moments were calculated., Results: Survival rates after ageing were 100% for all groups. Apart from wear facets (ϕ 2-3 mm) on the palatal restoration surface, no complications were observed. The mean fracture load and bending moments ranged between 597.6-847.1 N and 433.3-550.6 Ncm, respectively, with no significant differences between the eight groups (p = .25; p = .20)., Conclusions: As patient-specific temporary shell central and lateral incisor provisional implant-supported restorations are mechanically stable enough to withstand clinical bite forces, even after thermo-mechanical ageing, they may serve as an alternative to laboratory-fabricated provisional restorations., (© 2024 The Author(s). Clinical Oral Implants Research published by John Wiley & Sons Ltd.)

Objectives: When dental practitioners encounter a defective restoration, they are faced with a crucial decision whether to repair or replace it. This study aims to explore international preferences for repair procedures and the clinical steps taken during the repair process., Method: An 11-question survey was distributed to dentists across 21 countries via different platforms. The survey comprised two sections: the first included five questions aimed at gathering demographic information, while the second consisted of six questions focusing on participants' practices related to the repair of composite or amalgam restorations A meta-analysis was employed to ascertain the pooled odds ratio of repairing versus replacement. The statistical analysis was carried out using the RevMan 5.3 program and forest plots were generated using the same program to visualize the results., Results: The survey was completed by 3680 dental practitioners. The results indicated a strong tendency to repair defective composite restorations (OR: 14.23; 95 % CI: 7.40, 27.35, p < 0.001). In terms of amalgam, there was a significant tendency to replace the restorations (OR: 0.19; 95 % CI: 0.12, 0.30, p < 0.001). When repairing restorations, the most common protocols were etching with orthophosphoric acid and creating an enamel bevel, regardless of the restorative material used., Conclusion: The findings of this study indicate that there exists a knowledge gap among dental practitioners regarding restoration repair. It is imperative that dental practitioners receive proper education and training on restoration repair, to ensure the usage of adequate protocols and restoration survival., Clinical Significance: A significant portion of dental practitioners lack the necessary knowledge and education required for the repair of restorations. Therefore, it is imperative to establish guidelines aimed at enhancing the management of defective restorations, along with protocols for clinical interventions. This includes the incorporation of proper courses in undergraduate, graduate, and continuing education programs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the clinical conditions of single-unit posterior restorations on teeth prepared without finishing line, after 5.6 years of clinical service., Materials and Methods: 50 crowns (25 zirconia-based (Zr) and 25 porcelain-fused-to-metal (PFM)) were selected from 34 patients. The restorations were evaluated according to the California Dental Association (CDA) Quality Criteria, and periodontal variables were studied in the abutment teeth compared with the unrestored contralateral teeth. Variables were examined using Mann-Whitney and Pearson´s Chi-Square tests (α = 0.05). The success of the prosthesis was calculated using Kaplan-Meier test., Results: CDA Quality Criteria was considered satisfactory-excellent in all restorations except for one of them, due to chipping on a PFM crown. At, 66 months, the success rates for PFM and Zr crowns were 85.7 % and 100 %, respectively. The plaque index (PI) showed that the restored abutment teeth accumulated significantly less plaque than the control teeth, but the gingival index (GI) was statistically higher in the abutment teeth. In 80 % of cases the probing depth (PB) was ≤3 mm. In addition, in 21 % of the cases, gingival recession was less than 2 mm. The restoration material had a statistically significant effect on GI and PB, with Zr crowns showing less inflammation and less deep pockets than PFM restorations. On the contrary, greater gingival recession was found at the margins of the Zr crowns when compared to the PFM. No statistical differences were found between the two materials in the GI., Conclusions: Cemented crowns on vertical preparations show good clinical behavior after 5 years. The periodontal parameters (PI, GI, PD) of the Zr restorations are significantly better than those of PFM, with the exception of gingival recession., Clinical Relevance: The use of restorations on vertically prepared teeth is a suitable alternative to classical horizontal preparations., Competing Interests: Declaration of competing interest Mario Gonzalez-Bonilla declares that he has no conflict of interest. Santiago Berrendero declares that he has no conflict of interest. Belen Moron-Conejo declares that she has no conflict of interest. Francisco Martinez-Rus declares that he has no conflict of interest. Maria Paz Salido declares that she has no conflict of interest., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objectives: to assess the survival rates of removable partial dentures (RPDs) and identify factors impacting their longevity., Methods: electronic health records were retrieved of patients aged ≥18 who received RPDs between 2010 - 2021 with a follow-up of ≥ three months. Data extracted included demographics, medical history, dental charting, periodontal screening and recording scores, prostheses details and related interventions, including new dentures/denture remakes, and maintenance. Multivariate Mixed-Effect Cox regression was performed to identify potential RPD survival risk factors. Reduced model selection was reached using a backward step-down by comparing the performance of these multivariable models using the ANOVA test., Results: 1893 RPDs from 1246 patients were included, with a median follow-up of 21.8 months (range from 3 to 131.3 months). Three hundred and twelve patients received a maxillary RPD, 460 received a mandibular RPD, and the remaining 474 patients received both maxillary and mandibular RPDs. Metal-based RPDs had a median survival of 73 months (95%CI: 70 - 82) versus 45 months (95% CI: 37-67) for acrylic ones. Multivariable mixed effects Cox model showed that the lifespans of RPDs were longer amongst patients receiving more maintenance care within three months [Hazards Ratio (HR)=0.89 (0.83, 0.96)] and after three months [HR=0.53 (0.46, 0.61)] of denture delivery, patients wearing both maxillary and mandibular RPDs [HR=0.67 (0.52, 0.87)], and patients receiving metal-based RPDs [HR=0.31 (0.23, 0.42)]., Conclusions: Metal-based dentures, dual arch restoration, and increased maintenance positively impact the survival of RPDs., Clinical Significance: Adapting consent and warranty practices is advised to reflect RPD performance variations., Competing Interests: Declaration of competing interest No conflict of interest was present at the time of preparing this manuscript. There is no internal or external funding to report., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The high success rate of current dental implant protocols makes studies of catastrophic failures a rarity; however, this article presents a case study in which faulty medical intervention was the direct cause of traumatic implant failure. The patient, who had been treated with implants that successfully osseointegrated, ultimately experienced a life-threatening medical incident due to an ill-fitting definitive prosthesis. This case report includes a detailed narrative of how this patient, who began his dental journey with compromised and missing teeth, became edentulous and then, following an arduous recovery, was restored to full function with a meticulously planned revision treatment. Today, after enduring radical and perhaps unnecessary treatment and physical and mental trauma, the patient is tolerating osseointegrated implants with both maxillary and mandibular prostheses that are comfortable and well-functioning.

Statement of Problem: The impact of various preparation designs on the fracture resistance and fracture type of mandibular premolars restored with 3 dimensionally (3D) printed, 1-piece endodontic crowns remains unclear., Purpose: The purpose of this study was to investigate the effect of different preparation designs on the fracture resistance and fracture patterns of mandibular premolars restored with 3D printed 1-piece endodontic crowns after thermal aging., Material and Methods: Forty-five freshly extracted mandibular premolars received 3 different preparation designs: with at least 2 intact cuspal walls (2CW), with only 1 intact cuspal wall (1CW), and no cuspal wall present (NoCW). One-piece endodontic crowns were designed by using a computer-aided design (CAD) software program, 3D printed, cemented to the prepared teeth with self-adhesive resin cement, and thermocycled between 5 °C and 55 °C in artificial saliva. Subsequently, all specimens were subjected to a fracture test. The results were statistically analyzed using 1-way ANOVA (α=.05), and fracture types of all specimens were examined using a light microscope., Results: The analysis of fracture resistance values across separate designs revealed no statistically significant differences (P>.05). Mean fracture resistance values were 724.5 N in 2CW, 713 N in 1CW, and 861 N in NoCW. In 2CW and 1CW, the 1-piece endodontic crowns mostly displayed Type III fractures, whereas those in NoCW exhibited a combination of Type II and Type III fractures., Conclusions: The mandibular premolar 1-piece endodontic crowns tested in this study exhibited similar fracture resistance and type of fracture with different preparation designs., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Peri-implantitis occurs around dental implants, and implantoplasty has been used to address this ongoing disease; however, the changes to the physical properties of an implant after implantoplasty have not been well documented., Purpose: The purpose of this in vitro study was to determine the effect of implantoplasty on fracture strength and the load required for plastic deformation after cyclic fatigue on dental implants., Material and Methods: Twenty-six titanium/zirconium (TiZr) alloy implants (Roxolid Bone Level Implant; 4.1×10 mm) were embedded with 50% thread exposure and divided into 4 groups based on whether they had implantoplasty treatment by using different diamond rotary instruments and/or cyclic loading at 250 N for 2 million cycles: C0 (control, no cyclic loading), T0 (test, no cyclic loading), CM (control, cyclic loading), and TM (test, cyclic loading). After implantoplasty and/or cyclic loading, all implants underwent a load-to-failure test. The maximum fracture strength (FS) and load required for the onset of plastic deformation (PD) were recorded in Newtons. One-way ANOVA and nonparametric comparisons with control by using the Dunn and Wilcoxon method for joint ranking were used for statistical analysis., Results: The mean ±standard deviation FS for C0, CM, T0, and TM was 1465.2 ±86.4 N, 1480.7 ±64.1 N, 1299.3 ±123.8 N, and 1252.1 ±85.7 N, respectively. The mean ±standard deviation load for onset of PD for C0, CM, T0, and TM was 860.2 ±88.1 N, 797.0 ±130.5 N, 776.5 ±181.8 N, and 631.3 ±84.5 N, respectively. The TM group had a significantly lower FS and PD than the C0, CM, and T0 groups (P<.05) CONCLUSIONS: Both fracture strength (FS) and the onset of plastic deformation (PD) were significantly reduced after a TiZr alloy implant received implantoplasty and cyclic loading., (Copyright © 2022 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objective: This systematic review aimed to analyze the clinical (survival rate, failure risk, or fracture) and laboratory performance (fracture mode or failure) of rehabilitations of endodontically treated teeth, with and without posts., Materials and Methods: A systematic search was conducted in the Pubmed, Scopus, Web of Science, Embase, Cochrane Library, and OpenGrey databases up to March 2023, according to PRISMA guidelines. In vitro and clinical studies that compared the clinical and laboratory performance of endodontically treated teeth with and without intraradicular posts were included. Studies selection, data extraction, and risk of bias analysis were performed., Results: Thirty-one in vitro and 7 clinical studies were included. For in vitro studies, fiberglass post (n = 24) was the most mentioned. The follow-up time of the clinical studies ranged from 1 to 17 years, with the fiber-reinforced composite post (n = 3) being the most evaluated, and only failure risk proved to be more favorable for using intraradicular posts., Conclusion: Rehabilitations of endodontically treated teeth with and without intraradicular retainers showed no difference in fracture resistance and failure mode, evaluated by in vitro studies. Clinical studies showed no difference in survival rate, but failure risk proved to be more favorable for the use of posts., Clinical Significance: This analysis revealed significant variability between results, however, most laboratory and clinical studies revealed no difference with using the post. Furthermore, it is important to emphasize the need to evaluate the coronary remnant and the general characteristics of the tooth in each situation., (© 2024 Wiley Periodicals LLC.)

Objectives: To evaluate structural damage and loosening of abutments placed on narrow diameter implants after cyclic fatigue., Methods: Sixty Morse taper narrow diameter implants (Neodent, Brazil) received two types of abutments (1PA- one-piece abutment or 2PA- two-piece abutment), which were randomly divided into 3 fatigue experiments (n = 10). The implants were placed into a customized supporting holder and a software-assisted digital torque wrench secured the manufacturer recommended torque for each abutment. Cone beam computed tomography (CBCT) scans were acquired, before and after fatigue, and post-processed (software e-Vol DX) to assess damage and abutment displacement. The boundary fatigue method was adapted to use 2 × 10 6 cycles, 2 Hz of frequency and constant peak load of 80 N (first experiment) that varied according to the failure rate of previous specimens (second and third experiments). Failure was evaluated using CBCT scans and removal torque values. Data were used to estimate long-term torque degradation, probability of failure and Weibull modulus (software ALTA PRO9)., Results: All 2PA specimens became loosen independently of the applied fatigue load, and structural bending was observed in 14 abutments. Eight 1PA got loosen during the fatigue experiment. The Weibull analysis showed a lower modulus (m = 1.0; 0.7, 1.4) for 1PA than for 2PA (m = 2.6; 2, 3.4) resulting in longer predicted lifetimes and slower torque degradation for 1PA than for 2PA specimens., Significance: 1PA showed greater long-term survival probability than 2PA. Predicting the lifetime and mechanical behavior of implant-abutment systems are useful information to clinicians during the decision-making process of oral rehabilitations., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Statement of Problem: Various options are available to allow angle correction for screw-retained restorations for malaligned implants, including angled abutments, angled screw channel abutments, and angled implants. However, the effect these angle correction components have on prosthetic screw loosening is unclear., Purpose: The purpose of this systematic review was to assess the effect of angled abutments, angled screw channel abutments, and angled implants on prosthetic screw loosening., Material and Methods: This manuscript followed the Preferred Reporting Items for the Systematic Review and Meta-Analyses (PRISMA) statement. Searches were performed through 31 December 2021 in PubMed/MEDLINE, EMBASE, and Web of Science with no year limit targeting in vitro studies evaluating the effect of angulation correction components on screw loosening., Results: A total of 460 articles were identified. After removing duplicates, 306 titles were screened. Nine of the remaining 36 articles selected for full-text analysis met the selection criteria. The qualitative analysis used data from 394 implants. All studies featured straight abutments as the control group, and, in 8 studies, the angle correction component was included on the level of the abutment. Only in 1 study was the angle correction component at the level of the implant. The angle correction of the prosthetic component varied from 0 degrees in all studies up to a maximum correction of 30 degrees. Statistically significant increases in screw loosening with increasing abutment angle correction were reported by multiple authors (P<.05). However, other articles reported nonsignificant differences in screw loosening because of angulation after cyclic loading (P>.05). The only study investigating angle correction at the implant level found significantly less screw loosening (P<.05) in the angled implant group compared with the nonangled implant group., Conclusions: Several options are available to correct discrepancies between the surgical axis and the ideal prosthetic axis for rehabilitations supported by dental implants. The current evidence does not clearly indicate the superiority of any single solution for minimizing screw loosening., (Copyright © 2022 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: To identify the factors affecting the risk of bonded fragment loss in crown-fractured anterior teeth managed by fragment reattachment., Methods: The study protocol followed the best practices of evidence-based medicine and was registered in PROSPERO. A comprehensive literature search was performed electronically in six databases (PubMed, Embase, SCOPUS, Web-of-Science, Lilacs, and Cochrane) on 18-09-2023. It was saved in EndNote-online and duplicates were removed. Selection of articles was performed in two stages, followed by data-extraction, risk of bias assessment, data-analysis, and meta-analysis. The quality of evidence for the outcomes was assessed by the GRADE-approach., Results: The study included six articles that had similar selection protocols with variations in duration from trauma to treatment and the observation period. Only one study employed pre-attachment fragment preparation and three performed post-attachment reinforcements. Overall loss of fragment was 20% (95%CI-13,30%). When the risk ratio for loss of restoration or fragment was compared, it was found to be 2.21 (95%CI-1.52,3.21) in uncomplicated crown fractures, 2.54 (95%CI-1.35,4.79) in complicated crown fractures. The risk of bias was found to be low in two and moderate in four studies. Grade of evidence for all the outcomes was very low., Conclusion: Fragment loss was lowest in uncomplicated crown fractures where reinforcement had been performed, and highest when bonding was done in complicated crown fractures without reinforcement. The risk of fragment loss was higher than the loss of composite restorations., (© 2024. The Author(s), under exclusive licence to British Dental Association.)

Design: This retrospective cohort study aimed to investigate the risk and variables of tooth loss for teeth adjacent to dental implants compared to teeth nonadjacent to implants. The study followed the STROBE guidelines and was approved by the Institutional Review Board., Cohort Selection: The study included patients treated with dental implants at UCSF School of Dentistry between 2000 and 2020. The inclusion criteria for teeth adjacent to implants required the implant to support a fixed prosthesis and a follow-up period of at least 12 months. Nonadjacent teeth also required a follow-up period of at least 12 months. Teeth were excluded if they had a hopeless prognosis or were planned for extraction before the completion of restorative treatment., Data Analysis: Data were extracted from electronic health records, including patient demographics, dental histories, and outcomes for teeth adjacent and nonadjacent to implants. Statistical analyses, including Kaplan-Meier survival plots, log-rank tests, and multivariate logistic regression, were used to compare tooth survival and identify aetiologies of tooth loss., Results: The study included 787 patients, with 2048 teeth adjacent and 15,637 teeth nonadjacent to implants. The 10-year cumulative survival rate was 89.2% for teeth adjacent to implants and 99.3% for nonadjacent teeth. Teeth adjacent to implants had a significantly higher risk of tooth loss (Odds Ratio [OR] 13.15). The primary etiology of tooth loss adjacent to implants was root fracture (45.2%), followed by caries (28.9%), periodontitis (24.1%), and endodontic failure (1.8%). For nonadjacent teeth, periodontitis was the leading cause of tooth loss (51.9%)., Conclusions: The study found that teeth adjacent to dental implants had a significantly higher risk of tooth loss, primarily due to root fractures. The findings suggest that dental implants may act as an iatrogenic factor, increasing the risk of complications for adjacent teeth. Conservative management of natural dentition should be prioritized, with emphasis on stringent periodontal surveillance and effective home care. Future research should focus on prospective studies to further explore these associations and improve clinical outcomes., (© 2024. The Author(s).)

A conservative approach to restoration assists in preserving the remaining tooth structure of extensively destroyed vital teeth. This case report describes a single-appointment chairside technique for placement of ceramic restorations in posterior teeth. A patient presented for treatment of her mandibular right first molar, which had a fractured resin-based composite restoration. Due to the presence of vital pulp, extent of the restoration, and presence of caries in the tooth, the following treatment plan was proposed: placement of a lithium disilicate glass-ceramic onlay fabricated with a computer-aided design/computer-aided manufacturing workflow. After the dentist removed the restoration and performed selective caries removal, structural analysis guided the reduction of the buccal cusps. Immediate dentin sealing was performed with a 2-step self-etching adhesive system, and a 1-mm-thick layer of flowable resin-based composite was placed as a resin coating. A digital impression was obtained, the onlay restoration was designed, and a lithium disilicate block was milled and subsequently crystallized. When the onlay was completed, the tooth preparation was sandblasted, selectively etched, and coated with a universal adhesive. The intaglio surface of the onlay was cleaned and primed, the onlay was bonded with dual-cure resin cement, and occlusal adjustments were completed. Follow-up examinations at 1 and 4 months revealed the clinical success of the case. From start to finish, it takes approximately 2.5 hours to produce a single-appointment chairside restoration. The technique used in this case offers a fast-paced workflow that is comfortable and practical for the patient and provides a predictable clinical outcome without the need for a temporary restoration., Competing Interests: No conflicts of interest reported.

Objectives: This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant-supported single crowns with external connections under mechanical cycling., Materials and Methods: Fifty specimens were divided into groups: (1) metal-ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB). Specimens underwent mechanical cycling (5 × 10 6 cycles; 150 N) evaluating fatigue resistance (number of failures) and those that failed were subsequently subjected to fractographic analyses (stereomicroscope and scanning electron microscope) to evaluate failure location and area, and maximum fracture load was also measured., Results: The failure-related survival rate (100%) and maximum fracture resistance of the MZrB were significantly higher than those of MC and Zr (50%; p < 0.05). There were no significant differences in the failure rate and fracture resistance when a CoCr base abutment was used or not in the translucent monolithic Zr groups (p > 0.05;MZrB vs. MZr). Failure location, with MC crowns' fractures, noted at the screw area (p = 0.043), while all-ceramic crowns were mostly in the cuspid and to failure area, the Zr group had the largest mean (15.55 ± 9.17 mm 2 ) among the groups, significant difference only when compared with MC (1.62 ± 0.81 mm 2 ) (p = 0.025)., Conclusions: Translucent monolithic zirconia crowns exhibited significantly higher fatigue and fracture resistance compared with conventional MC and bilayered crowns., Clinical Significance: The appropriate choice of material and manufacturing technique is crucial for predicting the higher clinical performance of single crowns. Enhanced mechanical resistance in terms of fatigue and fracture resistance can be achieved by replacing MC and bilayered restorations with computer-aided design and computer-aided manufacturing monolithic zirconia., (© 2024 Wiley Periodicals LLC.)

Objective: To investigate fatigue methods for the evaluation of translucent zirconia and to associate in vitro failures with clinically reported ones., Data: Studies published in English that used fatigue tests on dental translucent zirconia., Sources: Two databases (MEDLINE/PubMed and Scopus) were electronically searched without any restriction on year of publication., Study Selection: A total of 4555 studies were identified. After removal of duplicates (78) and irrelevant articles (4316) that did not meet the inclusion criteria, 161 articles were considered eligible based on their titles and abstracts. These articles were fully read, leading to the inclusion of 41 studies in the review., Results: The most widely used fatigue method for evaluation of translucent zirconia was step-stress (18 articles), followed by staircase (seven articles), and step-wise (two articles). Most studies had been conducted in a wet environment with the use of a stainless steel piston to apply load to cemented structures on a dentin-like substrate. Most fracture analyses indicated the fracture originated on the cementation or contact surface where the load was applied. Moreover, studies that utilized anatomical structures (dental crowns) reported fractures starting at the cervical margin of the crowns., Conclusion: Most studies used the step-stress method. Only three studies reported failures similar to those found in clinical trials that used translucent zirconia restorations., Clinical Significance: The study findings can assist on correlating clinical failures to the ones observed in vitro., Competing Interests: Declaration of competing interest The author (ADB) is an Editorial Board Member of Journal of Dentistry and was not involved in the editorial review or the decision to publish this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: This study aimed to evaluate the incidence of implant failure in patients with oral lichen planus (OLP) and investigate the potential association between OLP and peri-implant diseases., Materials and Methods: Embase, Web of Science, PubMed, and Scopus databases were searched for studies with no time restrictions. Meta-analysis was performed calculating pooled proportion of peri-implantitis (PI), peri-implant mucositis (PIM), and bleeding on probing (BOP) prevalence using fixed-effects model. Odds ratio and corresponding 95% CI were calculated to assess the potential risk of PI, PIM, and BOP in dental implant patients with OLP compared to healthy controls., Results: Implant failure rate was 4.38% at the patient level and 4.37% at the implant level. Six patients (3.92%) from five studies were diagnosed with oral cancer after receiving implant. The prevalence of PI, PIM, and BOP at the implant level were 14.00%, 20.00%, and 40.00%, respectively. There was no significant difference in the occurrence of PI and PIM between OLP patients and healthy controls., Conclusions: Stabilized OLP is not considered a significant risk factor for peri-implant diseases. It is advised against placing implants or prostheses during the acute phase of the disease. Histopathological investigation to differentiate OLP from oral lichenoid dysplasia is crucial., (© 2024 Wiley Periodicals LLC.)

AimTo systematically scrutinise the scientific literature to evaluate the accuracy of computer-guided implant placement for single missing teeth, as well as to analyse the eventual clinical advantages and treatment outcomes.Material and methodsThe electronic and manual literature search of clinical studies published from January 2002 up to November 2015 was carried out using specified indexing terms. Outcomes were accuracy; implant and prosthetic failures; biological and mechanical complications; marginal bone loss (MBL); sulcus bleeding index (SBI); plaque score (PS); pink esthetic score [PES]; aesthetic and clinical outcomes.ResultsThe search yielded 1027 relevant titles and abstracts, found during the electronic (n = 1020) and manual (n = 7) searches. After data extraction, and screening of titles, abstracts, and full-texts, 32 studies fulfilled inclusion criteria and were included in the critical review: two randomised controlled clinical trials, six prospective observational single cohort studies, one retrospective observational study, three in vitro comparative studies, 10 case reports and 10 systematic reviews. A total of 209 patients (18 to 67 years old) were treated with 342 implants using computer-guided implant surgery. The follow-up ranged from 12 to 52 months. The cumulative survival rate ranged from 96.5% to 100%. Eleven implant planning softwares and guided surgery systems were used and evaluated.ConclusionsComputer-guided surgery for single missing teeth provides comprehensive treatment planning, reliable implant positioning, favourable clinical outcomes and aesthetics. A tooth-supported template for the treatment of single missing teeth results in greater accuracy of implant positioning than with mucosa-supported or bone-supported templates. The limited scientific evidence available suggests that guided surgery leads to implant survival rates as good as conventional freehand protocols. Computer-guided surgery implies additional costs, that should be analysed in terms of cost-effectiveness, considering the reduction of surgery time, postoperative pain and swelling, as well as, the potential increased accuracy. Long-term randomised clinical trials are eagerly needed to investigate the clinical performance of guided surgery in partially edentate patients.

Aim: A retrospective, cross-sectional study was carried out to evaluate the performance of resin composite restorations placed by undergraduate dental students with 1 to 15 years of placement based on dental records. Methods: Four calibrated operators evaluated 498 restorations (anterior and posterior) of 120 patients according to Ryge’s validated criteria (USPHS). Results: The criteria that showed the smallest changes between the types of failures were color matching, marginal discoloration and surface texture. Regarding the longevity, the surface texture showed an increase in the frequency of failures from the second time interval (3.1 to 6 years). Higher prevalence of failure was found in class II and III restorations, with secondary caries being the main reason. No significant differences were found for anatomic form, marginal adaptation, and color matching. Class V restorations showed a higher fracture rate with total displacement of the restoration, with no increase in the frequency of fracture over time. Conclusion: High rate of restoration failure was observed, possibly due to the lack of experience and skills of the students. This outcome highlight the need for continuous revision and improvements of teaching practice regarding the development of clinical competences and skills by dental students.

Objectives: Evaluate the need for re-intervention on dental coronal restorations in adults seen in a network of general dental practitioners (ReCOL). Materials and methods: This observational, cross-sectional, multicenter study involved 40 practitioners and 400 patients. Coronal restoration failures (needing re-intervention for unsatisfactory outcomes) were assessed with a simplified rating scale of seven criteria from the FDI World Dental Federation. The oral health status, the risk factors, and Oral Health Impact Profile-14 were also examined. Previous restoration characteristics (extent, technique, material) were analyzed according to the need for re-intervention (yes/no), the age group, and the risk profile. Qualitative variables were compared between "re-intervention" and "no re-intervention" group using Fisher exact test. Results: The need for re-intervention was estimated at 74% (95% CI: 70; 79); it increased with age (49 to 90%), unfavorable risk profile (82 vs. 62%), and extent of the filling (32, 39, 44, and 44% on 1, 2, 3 surfaces, and crowns, respectively). More posterior than anterior teeth were restored (median per patient: 6 vs. 1) or needed re-intervention (median per patient: 1 vs. 0). Conclusions: The needs for re-intervention in adults are still high within a context of ever-changing materials and techniques, simplified and rationalized decision-makings, and demands for patient involvement. Clinical relevance: Meeting these needs requires the following: (i) consensus definitions and assessment methods for "failure" and (ii) reliable feedbacks on materials, procedures, and satisfaction. Building large and detailed databases fed by networks of motivated practitioners will help analyzing complex success/failure data by artificial intelligence and guiding treatment and research. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the prevalence of unsatisfactory dental restorations on posterior primary teeth and associated factors in school children aged six to ten years. A cross-sectional study was conducted with children randomly selected from public schools in a small Brazilian town. Questionnaires were sent to the guardians addressing socioeconomic and behavioral aspects of the child. Oral examinations were performed at the schools to determine the quality of dental restorations, visible biofilm, and presence of moderate/extensive untreated caries (scores 3-6 ICDAS). This examination was performed by two previously trained and calibrated examiners. Associations were tested using multilevel logistic regression. Among the 400 children evaluated, 98 had restorations (217 teeth). The prevalence of unsatisfactory restorations was 34.6%. Restorations in amalgam were less likely to fail compared to those in glass ionomer cement (OR = 0.11; 95%CI: 0.02-0.49; p = 0.005). Children with moderate/extensive untreated caries were more likely to have unsatisfactory restorations (OR = 6.79; 95%CI: 2.20-20.93; p = 0.001). Children with a visible plaque index = 20% were also more likely to have unsatisfactory restorations (OR = 2.28 95%CI: 1.05-4.92; p = 0.036). The prevalence of unsatisfactory restorations was high. The occurrence of this outcome was associated with restorative material, presence of caries, and visible plaque. [ABSTRACT FROM AUTHOR]

Aim: A retrospective, cross-sectional study was carried out to evaluate the performance of resin composite restorations placed by undergraduate dental students with 1 to 15 years of placement based on dental records. Methods: Four calibrated operators evaluated 498 restorations (anterior and posterior) of 120 patients according to Ryge's validated criteria (USPHS). Results: The criteria that showed the smallest changes between the types of failures were color matching, marginal discoloration and surface texture. Regarding the longevity, the surface texture showed an increase in the frequency of failures from the second time interval (3.1 to 6 years). Higher prevalence of failure was found in class II and III restorations, with secondary caries being the main reason. No significant differences were found for anatomic form, marginal adaptation, and color matching. Class V restorations showed a higher fracture rate with total displacement of the restoration, with no increase in the frequency of fracture over time. Conclusion: High rate of restoration failure was observed, possibly due to the lack of experience and skills of the students. This outcome highlight the need for continuous revision and improvements of teaching practice regarding the development of clinical competences and skills by dental students. [ABSTRACT FROM AUTHOR]

Background: Tooth extraction socket in the aesthetic area is a major indication for immediate implant placement greatly improving patient satisfaction and preserving the alveolar ridge. However, the effect of non-axial force on the peri-implant bone with subsequent early implant failure remains unclear. Objective: Evaluate the prognosis of tilted implants immediately placed and restored with angled abutments in comparison to straight implants restored with straight abutments in the esthetic area (anterior or premolars) using computer-aided surgical guides. Material and methods: Badly decayed non-restorable teeth in the aesthetic zone (anterior or premolars) were extracted atraumatically. Immediately after guided implant insertion, the abutments were adjusted and placed according to the allocation group (0, 15, or 25-degree angle) then a temporary crown was performed out of occlusion in centric and eccentric relation. Early implant failure was assessed at three and six months. Results: There was no statistically significant difference between the two groups (P=0.305). Straight and angled abutment groups showed 6 (14.3%) and 8 (20%) failed cases, respectively. The post-hoc subgroup analysis showed no statistically significant difference between angle 15 and angle 25 degree groups where (P=0.686) or between Anterior and Premolar groups (P=0.853). Conclusion: There was no statistically significant difference in the failure rate when comparing angled to straight immediately placed & restored implants. This applies to both anterior and premolar implants. [ABSTRACT FROM AUTHOR]