Search

Objective: Artificial intelligence (AI) applications in restorative dentistry have remarkably increased in the past 5 years. This review outlines the applications, promises, and limitations of AI in the most performed procedures in restorative dentistry. Method and materials: An electronic search was performed in four databases: MEDLINE/PubMed, Embase, Web of Science, and Scopus. The search included articles published in English language without date restriction. Two independent reviewers assessed the eligibility of the studies and performed data extraction. Any discrepancy was resolved by the consensus of a third reviewer. Results: A total of 33 studies were included in this review. For AI applications in restorative dentistry, the included studies were classified into three main groups: (1) diagnosis, detection, and prediction of the disease, (2) detection and prediction of the longevity of dental restorations, and (3) teeth detection and treatments. For each study, the AI model, type of dataset, sample size, and main results (accuracy, precision, sensitivity, and specificity) were reported. Conclusions: AI systems are promising as advantageous aids for diagnosis, prediction, and treatment in dentistry, with a high degree of accuracy. Despite the AI promises, several limitations are still unresolved and must be addressed to bridge the gap between technology and clinical applications. [ABSTRACT FROM AUTHOR]

Objectives: To compare the mechanical performance of partially replaced (repaired) intra-coronal restorations to totally replaced ones in root canal-treated teeth. Methods: Thirty maxillary second premolars were selected according to strict criteria, mounted on moulds, and had mesio-occluso-distal (MOD) cavities prepared. Resin composite restorative material was used to perform the initial restoration, followed by aging procedures using thermo-mechanical cycling fatigue to replicate six months of intraoral aging. The specimens were then randomly divided into two groups: a totally replaced restoration (TR) group (n = 15), which involved the preparation of a traditional endodontic access cavity after the complete removal of the pre-existing coronal filling; and a partially replaced restoration (PR) group (n = 15), which involved accessing the tooth through the pre-existing restoration without completely removing it. Root canal preparation and filling procedures were conducted, and the access cavity was sealed with a new resin composite restoration, followed by a new thermo-mechanical cycling aging procedure. Finally, the specimens were submitted to a static fracture test to measure specimen fracture strength and determine the failure mode pattern (repairable fracture or irreparable fracture). Chi-square and t-tests were used for statistical analysis. Results: Significant differences between the groups regarding their mechanical resistance were found. The average failure load of the TR group was 1115.13 N and 1330.23 N in the PR group (p = 0.002). Regarding the failure modes, the TR group exhibited eight irreparable fractures, while the PR group had four (p = 0.136). Conclusions: Partially replaced restorations presented higher fracture strength and led to fewer irreparable fractures when compared to totally replaced restorations in root canal-treated teeth. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Overview Conclusion To investigate the nature and availability of evidence on the clinical performance of posterior partial coverage restorations (PCR) fabricated from different ceramic materials, outcome definitions, measurement methods, study drop‐outs and follow ups.A systematic literature search (inception‐February 2024) was performed through MEDLINE, Scopus, CENTRAL, ClinicalTrials.gov, and the International Clinical Trials Registry Platform to identify clinical studies with a focus on posterior PCRs (onlays, occlusal veneers and partial crowns) with a minimum follow‐up of 1 year. Thirteen of 31 included studies were randomized controlled trials (RCT) and 18 non‐randomized studies of intervention (NRS). Six RCTs compared two different ceramic materials and might be suitable for meta‐analysis. Differences in study design, definition of survival, evaluation methods, and statistical models for survival analysis were identified as reasons for expected heterogeneity among studies. The most common reasons for restoration failures were ceramic fractures and retention loss.The evidence informing the effect of PCRs varied in definitions of survival and failure, complication classifications, and workflow approaches. RCTs addressing clinical performance of PCRs comparing different ceramic materials are available for conducting systematic reviews and meta‐analyses. [ABSTRACT FROM AUTHOR]

Ceramic is a commonly used material in dentistry for reconstructing missing teeth or their tissues due to its biocompatibility, durability and excellent esthetic properties. Despite these advantages, the ceramic restoration damage remains a significant clinical problem. Its causes can be divided into clinical and laboratory factors. The most known include uneven occlusion, improper preparation, trauma, or parafunctions. This study focuses on characterizing less known laboratory causes of ceramic restoration damage. We reviewed the current literature available in the PubMed and Scopus databases. On the basis of 63 selected studies, 3 basic causes of damage were identified: excessive stresses between the framework and ceramic veneering, poor quality of the connection between the facing layer and the substructure, and defects resulting from the nature of the ceramic material such as defects in the ceramic layer, brittleness and lack of flexibility. The stages of the manufacturing process of various permanent ceramic restorations were presented. By controlling these procedures, we can eliminate the errors, resulting in long-term effective functioning of the ceramic restorations. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Material and Methods Results Conclusions Clinical Significance To analyze survival and complication rates for anterior and premolar laminate‐veneers out of different ceramic materials (feldspathic, leucite‐reinforced glass–ceramic [LRGC], lithium‐disilicate [LDS] and zirconia).A systematic literature search was conducted across multiple databases for clinical studies on ceramic laminate‐veneers with a minimum‐follow‐up of ≥ 1 year. The date of last search was on February 19, 2024. Survival, technical, esthetic and biological events were assessed for different laminate‐veneer materials at three observation periods (short‐ [1–3 years], mid‐ [4–6 years] and long‐term [≥ 7 years]).Twenty‐nine studies were included. Meta‐analysis revealed a pooled survival‐rate of 96.13% for feldspathic, 93.70% for LRGC and 96.81% for LDS at 10.4 years. No difference was found between materials. Complication rates (technical/esthetic/biological) were as follows: Feldspathic: 41.48%/19.64%/6.51%; LRGC: 29.87%/17.89%/4.4%; LDS: 6.1%/1.9%/0.45% at 10.4 years. Zirconia showed a 100% survival‐rate with no complications at 2.6 years. No long‐term data was available for zirconia.Feldspathic, LRGC and LDS laminate‐veneers showed high survival‐rates at long‐term observation. LDS slightly outperforms feldspathic and LRGC laminate‐veneers with lower long‐term complication rates. More studies providing long‐term data on zirconia laminate‐veneers are needed.Ceramic laminate‐veneers are a reliable treatment option. LDS may be preferred as a restorative material for long‐term success. [ABSTRACT FROM AUTHOR]

The aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of implant supported all-ceramic single-unit crowns, made by computer-aided-design/computer-aided-manufacturing (CAD-CAM). All-ceramic crowns placed in a private practice-based research network (Ceramic Success Analysis, AG Keramik) were analyzed. Data from 567patients with CAD-CAM implant supported all-ceramic crowns placed between 2008–2023 by 54dentists were evaluated. Firstly, all crowns with at least one follow-up control were included (n = 907). Secondly, all crowns being followed up for ≥ 5years and all failures were included (n = 151). At the latest follow-up visit, crowns were considered as successful (not failed) if they were still in function without the need for additional therapy. Multi-level Cox proportional hazards models were used to evaluate the association between a range of predictors and time of success. Within a mean follow-up period (SD) of 2.5 (2)years (first scenario) and 6.2 (1.2)years (second scenario) [maximum:12years], 27crowns failed (annual failure rate [AFR]:0.74 %). The main failure types were decementation, (n = 11), fracture of the ceramic (n = 4) or Ti-Base (n = 4). In 5-year-scenario, crowns fabricated in the laboratory had 26times lower failure rate than those fabricated chairside (95 %CI:0.0–0.7;p = 0.038). Furthermore, the use of a silane (HR:0.051;95 %CI:0.0–0.5;p = 0.014) and etching of the ceramic (HR:0.053;95 %CI:0.0–0.8;p = 0.035) resulted in a significantly higher risk for failure than their non-use. For CAD-CAM manufactured implant supported all-ceramic crowns, high success rates were found in up to 12-year evaluation. Furthermore, after 5years, no patient-or implant-level factors, but operative-level factor (i.e.fabrication method, use of silane/etching) were significantly associated with failure. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00020271). • Implant-supported ceramic crowns showed high success rates (97 %) after up to 12 yrs • After 5 years no patient-level factors were significantly associated with failure • After 5 years no implant-level factors were significantly associated with failure • Lab-side fabricated crowns showed a 26x lower failure rate than chairside ones [ABSTRACT FROM AUTHOR]

Objective: To evaluate the fracture behavior of human molars with extensive MOD restorations using short‐fiber‐reinforced resin composite of varying viscosities. Materials and Methods: Human molars were randomly divided into seven groups (n = 12): intact teeth (control); restoration using conventional high‐viscosity resin composite without (Filtek Z350XT, 3M) or with fibers (everX Posterior, GC); conventional low‐viscosity resin composite without (Filtek Supreme Flowable, 3M) or with fibers (everX Flow Dentin Shade, GC); bulk‐fill low‐viscosity resin composite (Filtek Bulk Fill Flow, 3M) or with fibers (everX Flow Bulk Shade, GC). Restorations were performed on extensive MOD preparations, following the manufacturers' recommendations for each material. Specimens underwent fracture strength testing (N) and fracture pattern (%) categorized as repairable, possibly repairable, or non‐repairable. Results were analyzed using a generalized linear model (N) and Fisher's exact test (%), with α = 0.05. Results: Restorations performed with high‐viscosity materials showed fracture strength values similar to the control and higher than those of restorations using low‐viscosity resin composites (p < 0.0001), except for the bulk‐fill low‐viscosity resin composite with fibers (p > 0.05). Teeth restored using low‐viscosity resin composite with fibers showed a higher % of repairable and possibly repairable fractures than the control (p = 0.0091). Conclusions: The viscosity of materials mediated the fracture strength, with restorations using high‐viscosity resin composites promoting values similar to the intact tooth; however, the presence of fibers influenced the fracture pattern. Clinical Significance: Teeth with MOD cavities restored with high‐viscosity resin composites showed similar fracture strength to intact teeth. Fiber‐reinforced low‐viscosity resin composite for the base of restoration resulted in a more repairable/possibly repairable fracture pattern. [ABSTRACT FROM AUTHOR]

Background: Several clinical and individual factors may play a role in the survival rate of dental restorations, such as characteristics related to the child's age and oral hygiene, and factors associated with the tooth, such as the type of material and number of surfaces to be restored. Aim: To analyse the survival rate of adhesive restorations on primary teeth and factors associated with restoration survival. Design: The study included dental records of children aged 3–12 years having received adhesive restorations on primary teeth at a Brazilian dental school between 2009 and 2019. A Kaplan–Meier survival curve was used to plot survival rates using the log‐rank test. A multivariate Cox regression model was run to identify individual and dental factors associated with restoration failure. Result s : The sample comprised 269 restored teeth in 111 children. Survival curves were similar for all materials (p =.20) and types of isolation (p =.05). The annual failure rate was 3.60% for glass ionomer cement, 1.23% for resin‐modified glass ionomer cement and 0.40% for composite resin. The following variables were associated with more failures: Class II restoration compared with Class I (HR = 1.96; 95%CI: 1.28–2.99, p <.001), proportion of decayed teeth (HR = 11.89; 95%CI: 2.80–50.57, p <.001) and child's age (HR = 1.17; 95%CI: 1.06–1.29, p <.001). Conclusion: The different materials and types of isolation had similar survival rates. Children with more decayed teeth have an increased risk of restoration failure. [ABSTRACT FROM AUTHOR]

In contemporary dental practice, clinicians have a variety of materials and options for restoring single teeth compromised by carious or non-carious diseases. According to studies and new concepts in biomimetic restorative dentistry, indirect ceramic restorations will play an increasingly important role in daily practice. We follow up and evaluate clinically three times over a 10-year period on eighty-six indirect restorations (n = 86) of lithium disilicate e.Max Press (Ivoclar, Schaan, Liechtenstein) in 32 patients. Restorations are evaluated in the 2nd, 5th, and 10th years after the fixation. Four of the restorations studied (n = 86) had to be replaced at year 5 follow-up because of fracture (failure rate: 4.65%; Kaplan–Maier). There are no restorations with bulky, cohesive fractures. Lithium disilicate ceramic restorations provide a good treatment alternative for a 5- to 10-year period of observation, and they can be successfully applied in dental practice in 91.73% to 98.84% of cases. Advancements in digital dentistry, including the use of intraoral scanners and CAD/CAM technology, are set to further refine the precision and efficiency of indirect restorations for distal teeth, enabling quicker turnaround times and improved fit. Additionally, ongoing developments in biomaterials promise to enhance the durability and biocompatibility of these restorations, potentially leading to better long-term success rates and patient satisfaction. The goal of this clinical study was to look at how well biomimetic ceramic overlays and onlays made of lithium disilicate held onto teeth with a IV-generation adhesive system for 10 years. The study also looked at how well the edges of the teeth adjusted and how strong the teeth were overall. [ABSTRACT FROM AUTHOR]

Abstract Objectives To compare the mechanical performance of partially replaced (repaired) intra-coronal restorations to totally replaced ones in root canal-treated teeth. Methods Thirty maxillary second premolars were selected according to strict criteria, mounted on moulds, and had mesio-occluso-distal (MOD) cavities prepared. Resin composite restorative material was used to perform the initial restoration, followed by aging procedures using thermo-mechanical cycling fatigue to replicate six months of intraoral aging. The specimens were then randomly divided into two groups: a totally replaced restoration (TR) group (n = 15), which involved the preparation of a traditional endodontic access cavity after the complete removal of the pre-existing coronal filling; and a partially replaced restoration (PR) group (n = 15), which involved accessing the tooth through the pre-existing restoration without completely removing it. Root canal preparation and filling procedures were conducted, and the access cavity was sealed with a new resin composite restoration, followed by a new thermo-mechanical cycling aging procedure. Finally, the specimens were submitted to a static fracture test to measure specimen fracture strength and determine the failure mode pattern (repairable fracture or irreparable fracture). Chi-square and t-tests were used for statistical analysis. Results Significant differences between the groups regarding their mechanical resistance were found. The average failure load of the TR group was 1115.13 N and 1330.23 N in the PR group (p = 0.002). Regarding the failure modes, the TR group exhibited eight irreparable fractures, while the PR group had four (p = 0.136). Conclusions Partially replaced restorations presented higher fracture strength and led to fewer irreparable fractures when compared to totally replaced restorations in root canal-treated teeth.

ABSTRACT Objective Materials and Methods Results Conclusions Clinical Significance To map the evidence regarding the clinical performance of posterior restorations with bulk‐fill resin composites and identify research gaps.This mapping review was conducted following PRISMA‐ScR guidelines for scoping reviews, and its protocol was registered on the Open Science Framework platform. Systematic searches were conducted, considering studies published between 2013 and February 2024 in the PubMed, Embase, and Cochrane databases. Clinical studies investigating the performance of bulk‐fill resin composite restorations in class I and/or class II preparations with increments of 4 to 5 mm were included.A total of 147 articles were identified, and based on the eligibility criteria, 26 studies were selected for descriptive analysis. Of the reviewed studies, 73% (n = 19) investigated high‐viscosity bulk‐fill composites, while 30% (n = 8) focused on low‐viscosity bulk‐fill composites. Evaluation periods ranged from 1 week to 10 years. Reported annual failure rates varied from 0% to 3%, with survival rates between 78.9% and 100%.Bulk‐fill resin composites of high viscosity were the most analyzed in the published studies, with evaluation periods of up to 10 years. The review of available scientific evidence showed clinically acceptable performance for composite bulk‐fill restorations, with high survival rates and minimal annual failure rates. There is a need for long‐term clinical studies on bulk‐fill resin composites.This review demonstrates that both high and low‐viscosity bulk‐fill resin composites exhibit satisfactory clinical performance, which can help clinicians optimize chairside time. However, it is important to highlight the need for further studies with longer follow‐up periods. [ABSTRACT FROM AUTHOR]

Objectives: The latest generation of bonding agents is increasingly embraced and well-suited to fulfilling the requirements for durable restorations. This study aimed to assess microleakage levels of three self-etch adhesives (Clearfil SE (SE), Protect (PB), and Tri-S (TS) Bonds) in composite restorations at both occlusal and cervical borders, while considering the impact of water storage over different time intervals. Methods: Standard Class V cavities were prepared on buccal surfaces of 84 human premolars at the level of cementoenamel junction. The samples were randomly assigned to six groups (N=14). The corresponding bonding procedure in each group was completed, and the cavities were filled using Clearfil AP-X (Kuraray). Following thermocycling, the teeth were stored in deionized water within an incubator for 24-hour and 6-month intervals. Statistical analysis of microleakage data was conducted utilizing Kruskal-Wallis and Mann-Whitney U tests at p<0.05. Results: Following a 24-hour interval, the level of microleakage at the occlusal surface was greater than the gingival surface for SE. No statistically significant differences were observed in microleakage at the occlusal and cervical borders after 24h of water storage for the PB and TS groups (P=0.51, 0.16). None of the SE and TS group samples showed leakage at the occlusal or cervical margins following a 6-month interval. Conclusion: Self-etching bonding agents indicated increased occlusal microleakage compared to the cervical margin microleakage. [ABSTRACT FROM AUTHOR]

Introduction: Endodontic therapy has been regarded as a safe treatment option with highly promising results in preserving natural teeth. Numerous factors may influence the longevity of endodontically treated teeth (ETT), thus altering their success/survival rate. This study aimed to determine the survival and success rates of endodontically treated premolars and molars with different complex restorative/prosthodontic treatments. Materials and Methods: A total of 190 patients with an ETT were included, who had received final coronal restoration up to 14 days after the temporary one and at least one year prior to the enrollment. The investigator evaluated the quality of endodontic filling, coronal restoration, mobility, and proximal contacts. Data were analyzed with multiple binary logistic regression and the Chi-Square test. Results: The average duration of followup was 28.6±11.9 months. Overall, 89.4% (170/190) of the teeth survived. The overall success rate for the investigated teeth was 70.5% (134/190). Success rates of 100% for crown, 95.7% for post and core crown (PCC), and 94.7% for amalgam build-up with post were achieved. However, the success rates were 75%, 52.5%, and 50% for amalgam build-up, composite build-up, and PCC with crown lengthening, respectively. The Chi-square test revealed that there was a significant difference between the different restorations in terms of success (P<0.001). Multiple binary logistic regression models revealed that coronal leakage (P=0.048), obturation void (P=0.037), obturation length (P=0.020), mobility (P=0.002), type of the restoration (P<0.001), and proximal contact (P<0.001) were significant predictors for success. However, apical lucency, root length, marginal caries, tooth type, and post did not appear to be significant indicators of success (P>0.05). Conclusions: ETT with minimal mobility, exhibiting underfilled obturations without visible voids, and having received crown/PCC/amalgam build-up with a post, along with the presence of both proximal contacts, tend to exhibit a significantly high success rate. [ABSTRACT FROM AUTHOR]

Introduction: Understanding the reasons for retreatment of dental restorations is crucial to preventing potential tooth failure. Due to limited information on retreatment causes in our region, this study aims to compare the factors leading to the failure of posterior amalgam and composite restorations. Materials & Methods: This cross-sectional, observational study was conducted on patients referred to the restorative department of Ilam Faculty of Dentistry and private clinics who required retreatment of existing posterior restorations. Failure criteria for posterior restorations were evaluated based on established reference guidelines. Results: The study found that secondary caries had an odds ratio (OR) of 3.08 (95% CI: 2.85 - 3.29; p < 0.001), indicating a strong association with restoration failure. Additionally, restoration fractures were significantly correlated with retreatment, with an adjusted OR of 2.50 (95% CI: 2.46-2.86; p < 0.001). Conclusion: Secondary caries emerged as the most common reason for retreatment, regardless of whether composite or amalgam materials were used. Restoration fractures also significantly contributed to the need for retreatment. Therefore, it is essential to consider factors such as restoration material, classification, and the number of restoration levels to reduce the likelihood of retreatment. [ABSTRACT FROM AUTHOR]

Abstract This study evaluated the effect of different occlusal surface finishes (glaze and silica glass infiltration) on surface characteristics and fatigue behavior of partially stabilized zirconia (PSZ) plates adhesively bonded onto epoxy resin discs. PSZ disc specimens (n = 15; Katana blocks STML, Kuraray Noritake Dental) were produced (Ø = 10 mm; thickness = 1.2 mm) and allocated into 3 groups: As sintered (S), silica glass infiltration (SGI), and glaze application (G). The PSZ intaglio surface was air-abraded with 50-µm alumina powder followed by bonding agent application. All produced PSZ were adhesively cemented onto dentin analogue discs made of epoxy resin material (Ø = 10 mm; thickness = 2 mm). Step stress fatigue test was performed (load ranging from 200 to 1800 N; step size 100 N and 10,000 cycles; 20 Hz). The topographic, microstructural, and fractographic analyses were performed by scanning electron microscopy. Results: No statistically significant difference in fatigue behavior was detected among the groups. All failures started at the bonding surface. Silica glass-infiltration and glaze layer application provided a smoothing effect, while the sintered group had a surface with grooves. The occlusal surface finishing method (silica glass infiltration or glazing) had no deleterious effect on fatigue behavior of adhesively bonded PSZ plates.

With the advancement of science over time, composite resins have undergone several scientific updates. Among these updates is the development of flow resins, characterized by high viscosity particles. But resins have some disadvantages, sunch as the formation of bubbles, a problem that was explored in this research. This article compared 4 different brands of flow resin (Opus Bulk Fill Flow Resin (FGM) - Filtek MR Bulk Fill Flowable (3M) - Tetric N-Flow Bulk Fill Resin and SDR Plus Bulk Fill Flowable Resin (DENSTPLY) took it under the microscope after applying these resins to laboratory prototypes, so that the formation of these bubbles can be evaluated more closely. As a result, it was possible to conclude that the Tetric N-Flow Bulk Fill brand resins are the flow composite resins that enable the formation of the smallest amount of bubbles in the process restorative. Tetric N-Flow Bulk Fill, due to its in vitro clinical performance superior to the competitors compared in this article, must be applied below the layer of conventional resin that will be used by the incremental technique with care in spatulation, so that formation can be avoided. of bubbles in a way that harms the restoration. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess whether immediate bone reconstruction after removal of a fractured dental implant in the posterior mandible provides a sound base for implant replacement, with a favourable treatment outcome and high patient satisfaction. Eight consecutive patients with a fractured implant neck were included. The implant was removed via osteotomy, following which the site was immediately repaired with a mixture of autogenous bone and bone substitute. After a 4-month healing period, sufficient bone and favourable soft tissue conditions were present, allowing implant placement with adequate primary stability. After a further 3 months, the implants were restored with an all-ceramic restoration. Patient satisfaction, the aesthetic outcome, complications, and postoperative morbidity were assessed using standardized clinical and radiographic examinations up to 5 years after crown placement. No implant failures were observed during the follow-up. Plaque accumulation, the presence of calculus, bleeding tendency, and peri-implant inflammation indices were low, indicating healthy peri-implant conditions. The mean marginal bone level change at the 5-year follow-up was − 0.17 ± 0.46 mm. All patients reported a high level of satisfaction (mean overall score 9.3 ± 0.5). In conclusion, immediate reconstruction of the hard tissue after removal of a fractured dental implant is a viable treatment option. This approach facilitates rehabilitation, reduces morbidity, and leads to favourable aesthetic outcomes. [ABSTRACT FROM AUTHOR]

Ichraq Oulghazi, Amal El Yamani, Bouabid Morchad Prosthodontics Department, Mohammed V University, Rabat, MoroccoCorrespondence: Ichraq Oulghazi, Prosthodontics department, Mohammed V University, Rabat, 10112, Morocco, Tel +212707163587, Email ichraqoul98@gmail.comPurpose: The aim of this work is to conduct a literature review to highlight all the parameters involved in sub-prosthetic radicular fractures of teeth supported by metallic dental core.Materials and Methods: The following research was performed among published studies over the last 10 years in two PubMed/Medline and Scopus and supplemented by manual searching within the bibliographies. The search was restricted to publications in English and French.Results: Out of the 1464 articles initially identified, 18 studies met our inclusion criteria and were subsequently included in the literature review. These consisted of eight Finite Element Analysis Studies, two Retrospective Studies and one Randomized Controlled Trial. The results of this review show that radicular fractures are influenced by several variables, including predisposition, with maxillary premolars and mandibular molars being the most commonly affected teeth. Intracanal preparation can induce crack formation, leading to localized high stress concentrations. Increased ferrule height to 2 mm significantly enhances dental fracture resistance. Using high modulus of elasticity alloys results in nearly complete stress transmission to dentin due to their limited deformability and absorption capacity. The highest fracture resistance is achieved when posts are sealed using resin-modified glass-ionomer cement. Longer posts may be preferable to prevent vertical fractures. Additionally, occlusal factors, through repetitive stresses, contribute to crack propagation from surface defects, a phenomenon termed fatigue fracture.Conclusion: These findings have significant implications. Practitioners should be aware of the predisposition of certain teeth, the importance of preserving the ferrule effect, the choice of root post materials, post Cement Material and the role of occlusal forces in managing and preventing vertical root fractures.Keywords: endodontically treated teeth, root fracture, radicular fracture, tooth fracture, dental restoration failure, biomechanical factor, stress factor, cast post, metal post, post and core technique, dental posts, metallic coronoradicular restoration

Abstract Background While the concept of angled screw channels has gained popularity, there remains a scarcity of research concerning the torque loss and fracture strength of monolithic zirconia restorations with various screw channel angulations when exposed to thermomechanical cycling. This in-vitro study aimed to evaluate the reverse torque value and fracture resistance of one-piece screw-retained hybrid monolithic zirconia restorations with angulated screw channels after thermomechanical cycling. Methods One-piece monolithic zirconia restorations, with angulated screw channels set at 0°, 15°, and 25° (n = 6 per angulation) were fabricated and bonded to titanium inserts using a dual-cure adhesive resin cement. These assemblies were then screwed to implant fixtures embedded in acrylic resin using an omnigrip screwdriver, and reverse torque values were recorded before and after thermomechanical cycles. Additionally, fracture modes were assessed subsequent to the application of compressive load. One-way ANOVA and Bonferroni post hoc test were used to compare the groups (α = 0.05). Results The study groups were significantly different regarding the fracture resistance (P = 0.0015), but only insignificantly different in the mean percentage torque loss (P = 0.4400). Specifically, the fracture resistance of the 15° group was insignificantly higher compared to the 0° group (P = 0.9037), but significantly higher compared to the 25° group (P = 0.0051). Furthermore, the fracture resistance of the 0° group was significantly higher than that of the 25° group (P = 0.0114). Conclusions One-piece hybrid monolithic zirconia restorations with angulated screw channels can be considered an acceptable choice for angulated implants in esthetic areas, providing satisfactory fracture strength and torque loss.

PURPOSE. The study aims to investigate the influence of the ferrule effect and types of posts on the stress distribution in three morphological types of the maxillary central incisor. MATERIALS AND METHODS. Nine models were created for 3 maxillary central incisor morphology types: "Fat" type - crown 12.5 mm, root 13 mm, and buccolingual cervical diameter 7.5 mm, "Medium" type - crown 11 mm, root 14 mm, and buccolingual cervical diameter 6.5 mm, and "Slim" type - crown 9.5 mm, root 15 mm, and buccolingual cervical diameter 5.5 mm. Each model received an anatomical castable post-and-core or glass-fiber post with resin composite core and three ferrule heights (nonexistent, 1 mm, and 2 mm). Then, a load of 14 N was applied at the cingulum with a 45° slope to the long axis of the tooth. The Maximum Principal Stress and the Minimum Principal Stress were calculated in the root dentin, crown, and core. RESULTS. Higher tensile and compression stress values were observed in root dentin using the metallic post compared to the fiber post, being higher in the slim type maxillary central incisor than in the medium and fat types. Concerning the three anatomical types of maxillary central incisors, the slim type without ferrule height in mm presented the highest tensile stress in the dentin, for both types of metal and fiber posts. CONCLUSION. Post system and tooth morphology were able to modify the biomechanical response of restored endodontically-treated incisors, showing the importance of personalized dental treatment for each case. [ABSTRACT FROM AUTHOR]

In contemporary dental practice, clinicians have a variety of materials and options for restoring single teeth compromised by carious or non-carious diseases. According to studies and new concepts in biomimetic restorative dentistry, indirect ceramic restorations will play an increasingly important role in daily practice. We follow up and evaluate clinically three times over a 10-year period on eighty-six indirect restorations (n = 86) of lithium disilicate e.Max Press (Ivoclar, Schaan, Liechtenstein) in 32 patients. Restorations are evaluated in the 2nd, 5th, and 10th years after the fixation. Four of the restorations studied (n = 86) had to be replaced at year 5 follow-up because of fracture (failure rate: 4.65%; Kaplan–Maier). There are no restorations with bulky, cohesive fractures. Lithium disilicate ceramic restorations provide a good treatment alternative for a 5- to 10-year period of observation, and they can be successfully applied in dental practice in 91.73% to 98.84% of cases. Advancements in digital dentistry, including the use of intraoral scanners and CAD/CAM technology, are set to further refine the precision and efficiency of indirect restorations for distal teeth, enabling quicker turnaround times and improved fit. Additionally, ongoing developments in biomaterials promise to enhance the durability and biocompatibility of these restorations, potentially leading to better long-term success rates and patient satisfaction. The goal of this clinical study was to look at how well biomimetic ceramic overlays and onlays made of lithium disilicate held onto teeth with a IV-generation adhesive system for 10 years. The study also looked at how well the edges of the teeth adjusted and how strong the teeth were overall.

Introduction and Objective: Although the use of ceramic veneers is widespread, their failures are seldom reported. When fractures do occur, they are often related to treatment planning. This case report describes a 6.5-year follow-up of a restorative treatment involving ceramic laminate veneers on a patient with a nail-biting habit. Case report: After two restorations failed, repair with composite resin was chosen as an intermediary treatment, and the clinical steps until the ultimate replacement of the ceramics are described. Results and Conclusion: The repair resulted in postponing the restorations replacement for almost five years. It highlights that replacement does not need to be the first treatment option in cases of failures of feldspar ceramic laminate veneers. These failures may be managed conservatively with a composite resin repair, with the advantage of postponing the need for replacement. [ABSTRACT FROM AUTHOR]

Abstract Resin composites containing surface pre-reacted glass (S-PRG) have been introduced to reduce demineralization and improve remineralization of the tooth structure. However, water diffusion within the material is necessary for its action, which can impair its overall physicomechanical properties over time, including color stability. This study aimed to evaluate the color stability and related degree of conversion (DC) of four resin composites. Discs (6 x 4 mm, n = 5/group) of microhybrid (MH), nanofilled (NF), nanohybrid (NH), and S-PRG-based nanohybrid (S-PRG-NH) composites with two opacities (A2/A2E and A2O/A2D) were prepared. Color (CIELab and CIEDE2000) was evaluated with a spectrophotometer after aging in grape juice (2 x 10 min/10mL/7days). The DC was analyzed by using Fourier transform infrared spectroscopy before and after light-curing. Data were statistically analyzed by using two-way analysis of variance and post-hoc least significant difference tests (p

Teeth with altered size and shape, incisal wear, and inadequate position affect the smile and dentofacial harmony. The aim of this article was to describe a simple and safe protocol for an additive technique with composite resin and cosmetic enameloplasty to improve a patient's smile. A 24-year-old man complained about the appearance of his smile regarding color, shape, and position of the maxillary anterior teeth. Relevant dental history included previous orthodontic treatment with inadequate completion. The clinical examination revealed a disharmony of the smile caused by size and shape alterations of the incisors, a white spot on the right central incisor, incisal wear of the canines, and uneven incisal edges between the maxillary anterior teeth. Treatment with direct composite restoration and enameloplasty was performed in line with the current conservative approach in dentistry. The patient was recalled for 54 months. The use of appropriate techniques in enameloplasty allowed the desired outcome to be observed over the 54 months of follow-up. With this method, it is possible to perform future repair and/or modification, and it may increase the longevity of the restoration. Esthetic and functional results were achieved by careful planning and execution as well as periodic recalls. This conservative approach is a useful alternative to conventional restorations, reducing invasive treatments, chairside time, and costs. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to investigate the load-to-fracture of procedures changing crown-to-root ratio (RCRR) aimed to restore severely damaged upper central incisors to avoid tooth extraction compared to implant placement. There is no evidence on load capability after apical root resection (AR), orthodontic extrusion (OE), and surgical crown lengthening (SCL) in respect to RCRR, respectively. Material and methods: Human maxillary central incisors were endodontically treated, decoronated, and divided into 4 groups (n = 48). The following specimen preparation was performed: (I) adhesive core-and-post build-up (control), (II) as (I) and 2 mm apical root resection (AR), (III) before adhesive core-and-post build-up teeth were shortened 2 mm coronally (OE) (IV) as (I), but specimens were embedded 4 mm instead of 2 mm below the CEJ (SCL), group (V) implant-borne restoration with individual all-ceramic abutments (n = 12; ∅4.1/l = 12 mm) (IBR). All specimens received all-ceramic crowns, thermo-mechanical (TML), and subsequent linear loading (LL) until failure. RCRR were calculated and log-rank, Kruskal–Wallis, Mann–Whitney U, ANOVA, and chi-square tests applied (p = 0.05). Results: Fracture loads after subsequent LL differed significantly (p = 0.001) between groups, while implants showed the highest values. Fmax median (min/max) were as follows: (I) 252 (204/542), (II) 293 (243/443), (III) 253 (183/371), (IV) 195 (140/274), and (V) 446 (370/539). Pair-wise comparison showed significant differences (p = 0.001) between group I/IV and group V, I, and IV (p = 0.045), II and IV (p = 0.001), and III compared to IV (p = 0.033), respectively. RCRR below 1 significantly increased load capability compared to RCRR = 1. Conclusions: OE appears to preferably ensure biomechanical stability of teeth that are endodontically treated and receive core-and-post and crown placement compared to SCL. AR has no adverse biomechanical impact. RCRR < 1 is biomechanically beneficial. Clinical relevance: For endodontically treated and restored teeth, orthodontic extrusion should be preferred compared to surgical crown lengthening prior single-crown restoration. As orthodontic extrusion, apical root resection has no adverse effect on load capability. Single-crown implant-borne restorations are most load capable. [ABSTRACT FROM AUTHOR]

Despite the widespread use of titanium implants in orthopedic and dental surgeries, concerns have recently emerged regarding potential deformations and fractures after osseointegration. In a recent clinical case, a titanium implant fractured after successful osseointegration. This fracture occurred despite the absence of any significant trauma or excessive external force applied to the area. The fracture was attributed to a combination of factors, including abutment design flaws, material fatigue, and biomechanical stress imposed on the implant during functional loading. This raises concerns about the long-term durability and reliability of titanium implants, particularly in high-stress areas such as the posterior region or weight-bearing bones. An image was made with scanning electron microscopy showing the fracture region near the prosthetic platform and highlighting the knowledge that despite their ductility, titanium implants can fracture. [ABSTRACT FROM AUTHOR]

Damage in the bonding interface is a significant factor that leads to premature failure of dental bonded restorations. The imperfectly bonded dentin-adhesive interface is susceptible to hydrolytic degradation and bacterial and enzyme attack, severely jeopardizing restorations' longevity. Developing caries around previously made restorations, also called "recurrent or secondary caries," is a significant health problem. The replacement of restorations is the most prevailing treatment in dental clinics, leading to the so-called "tooth death spiral". In other words, every time a restoration is replaced, more tooth tissue is removed, increasing the size of the restorations until the tooth is eventually lost. This process leads to high financial costs and detriment to patients' quality of life. Since the complexity of the oral cavity makes prevention a challenging task, novel strategies in Dental Materials and Operative fields are required. This article briefly overviews the physiological dentin substrate, features of dentin bonding, challenges and clinical relevance. We discussed the anatomy of the dental bonding interface, aspects of the degradation at the resin-dentin interface, extrinsic and intrinsic factors affecting dental bonding longevity, perspectives on resin and collagen degradation and how these subjects are connected. In this narrative review, we also outlined the recent progress in overcoming dental bonding challenges through bioinspiration, nanotechnology and advanced techniques to reduce degradation and improve dental bonding longevity. [ABSTRACT FROM AUTHOR]

Purpose: To report the performance of a repair service set for the retrieval of fractured screws and to compare three clinical assessments to an in vitro assessment to verify the completeness of removal of the fractured screws. Materials and Methods: Twelve clinicians were asked to remove fractured implant abutment screws from prepared specimens by means of a repair service set. The completeness of the removal of any abutment screw material was measured by the fit of an impression post, a dental surgery microscope, and the use of an elastomeric impression material. Results: After the participants attempted to remove the fractured screw with the repair service set, 100%, 83.3%, 66.7%, and 75% of the fractured screws were considered successful in the impression post, dental surgery microscope, silicone replica, and stereomicroscope assessments, respectively. Conclusion: The retrieval of fractured screws succeeded in 75% of the cases. The silicone replica technique and the dental surgery microscope had similar diagnostic values to the stereoscopic microscope assessment. [ABSTRACT FROM AUTHOR]

Objectives: To test if cigarette smoke (CS) causes discoloration of enamel, dentin, and composite resin restorations and induces color mismatch between dental hard tissues and the restorations, and to compare the findings with the effects of aerosol generated by the tobacco heating system (THS) 2.2. Method and materials: Twenty-two human premolars were prepared with Class V cavities restored with Filtek Supreme Ultra (3M Espe) composite resin. Teeth were divided into two groups and exposed to either CS from 20 reference cigarettes (3R4F) or aerosol from 20 THS 2.2 tobacco heat sticks 4 days a week for 3 weeks. CIE L*a*b* color was assessed before and after exposure and brushing at 1, 2, and 3 weeks. Color match, marginal discoloration, marginal integrity, and surface texture of the Class V restoration were assessed according to a modified US Public Health Service (USPHS) criterion. Results: Marked discoloration of enamel and dentin was observed following 3 weeks of CS exposure (ΔE = 8.8 ± 2.6 and 21.3 ± 4.4, respectively), and color mismatch occurred between the composite resin restorations (ΔE = 25.6 ± 3.8) and dental hard tissues. Discoloration was minimal in the enamel, dentin, and composite resin restorations in the THS 2.2 group, and no color mismatch was observed after 3 weeks of THS 2.2 aerosol exposure. Conclusion: CS causes significant tooth discoloration and induces color mismatch between dental hard tissues and composite resin restorations. Reducing or eliminating the deposits derived from tobacco combustion could minimize the impact of tobacco products on tooth discoloration. [ABSTRACT FROM AUTHOR]

Abstract Objectives The term “cracked tooth” is used to describe an incomplete fracture initiated from the crown and progressing towards a subgingival direction. Despite the high prevalence of cracked teeth and their frequent association with symptoms and pulpal or periapical pathoses, there is still no consensus in the literature with regard to their restorative and endodontic management. Therefore, the aim of this narrative review was to evaluate the most relevant research and provide an up‐to‐date comprehensive overview regarding the treatment of cracked teeth. Materials and Methods An electronic literature search was carried out in MEDLINE (via Ovid), Embase (via Ovid), Scopus, and Web of Science as well as several “Grey literature” sources up to February 22nd 2022 using a combination of pre‐specified ‘free‐text' terms (keywords) and “subject headings.” The search process was supplemented by handsearching in relevant dental journals and reference lists. This narrative review focused on clinical follow‐up studies (observational or interventional studies, case series/reports), laboratory studies and systematic reviews written in English language that reported data on treatment of permanent cracked teeth. The selection of relevant studies was carried out by two reviewers (AK and DG) working independently in two consecutive stages: title/abstract screening and full‐text retrieval. Any discrepancies in the study selection were resolved by discussion between the reviewers. Results In total, 64 articles were selected for inclusion in this narrative review. Conclusions Cracked teeth with normal pulp or reversible pulpitis have exhibited high pulp and tooth survival rates by the provision of direct or indirect composite restorations. Besides, recent data favour monitoring, especially in the absence of symptoms or compromised tooth structure. When endodontic intervention is required, current evidence suggests that along with appropriate restorative management, outcomes of cracked teeth may be comparable to those of non‐cracked root filled teeth.

Introduction: This randomized clinical study aimed to evaluate the clinical performance of composite and compomer materials in primary molars over two years. Methods: Children aged five to six years with at least two carious proximal surface primary molars were screened for resin-hybrid composite (Kerr Herculite Classic) and compomer (Dyract XP and R&D Series Nova) restorations. The restorations were clinically evaluated after 3, 6, 9, 12, 15, 18, and 24 months using the modified United States Public Health Service criteria. Statistical analyses were performed using Chi-square, McNemar, z-tests, and Kaplan-Meier survival analysis. P0.05). No significant differences were observed between the three materials concerning retention, color matching, marginal discoloration, anatomic form, marginal integrity, secondary caries, and surface texture (P>0.05). No statistically significant differences were also found between the effects of the cavity type, the tooth position in the arch, the age of the patient, the restorative material, and the lining material on the survival rates of the teeth (P>0.05). Restoration loss was higher in males than females, and a statistically significant relationship was observed in terms of gender (P=0.017). Restoration loss in the first primary molars (8.3%) was greater than that in the second primary molars (6.7%) (P=0.041). Conclusion: Both composite and compomer restorations were clinically successful over two years.

Dental treatment after endodontic therapy is quite challenging in clinical practice. While multiple post-and-core systems emerged and disappeared in the dental field, the historical process was laborious and still requires several up to date scientific evidence. Furthermore, once considered the gold standard, rigid metallic post-and-cores might be considered a limited option. Moreover, the development of glass-fiber posts and the biomechanical principles for root preparation bring multiple advantages, but also raise concerns over guidelines and indications. This review examined the classic literature so that clinicians may understand the concepts behind post endodontic restorative treatments and the doubts that still remain in the daily practice before performing this restorative modality.

Abstract Objectives This is a double-blind, split-mouth, randomized clinical study that aims to evaluate the influence of bulk-fill composite packaging presented in syringes (BSy) and capsules (BCa), and the effect of selective enamel etching (SEE) on the clinical performance of class I and II bulk-fill resin composite restorations after 24 months. Methodology A total of 295 class I or class II restorations were performed on 70 patients. One universal adhesive was applied in all restorations. SEE was used in 148 restorations and self-etching mode (SET) in 147 restorations. After the adhesive application, cavities were restored with Filtek Bulk-fill Posterior Restorative in syringes (BSy), Filtek One Bulk-fill in capsules (BCa), or Filtek Supreme Ultra in syringes with the incremental technique (In). All restorations were evaluated using the FDI criteria after one week and after six, 12, and 24 months. Kaplan-Meier survival analysis and Pearson’s Chi-square test were used (α=0.05) for statistical analysis. Results After 24 months, 62 patients were evaluated and four restorations were lost due to fracture (one for SEEBSy, two for SEEIn, and one for SETIn). No significant differences in the fracture and retention rate were found between groups (p>0.05). SEE showed significantly fewer marginal adaptation defects than SET (p

No evidence-based prosthetic treatment concept for 3-unit fixed-dental-prostheses (FDPs) on ceramic implants is currently available. Therefore, the aim of this in vitro study was to investigate the failure load and fatigue behavior of monolithic and bi-layer zirconia FDPs supported by one-piece ceramic implants. Eighty 3-unit FDPs supported by 160 zirconia-implants (ceramic.implant; vitaclinical) were divided into 4 groups (n = 20 each): Group Z-HT: 3Y-TZP monolithic-zirconia (Vita-YZ-HT); Group Z-ST: 4Y-TZP monolithic-zirconia (Vita-YZ-ST); Group FL: 3Y-TZP zirconia (Vita-YZ-HT) with facial-veneer (Vita-VM9); Group RL (Rapid-layer): PICN "table-top" (Vita-Enamic), 3Y-TZP-framework (Vita-YZ-HT). Half of the test samples (n = 10/group) were fatigued in a mouth-motion chewing-simulator (F = 98 N, 1.2 million-cycles) with simultaneous thermocycling (5–55 °C). All specimens (fatigued and non-fatigued) were afterwards exposed to single-load-to-failure-testing (Z010, Zwick). Statistical analysis was performed using ANOVA, Tukey's post-hoc tests and two-sample t-tests (p < 0.05, Bonferroni-corrected where appropriate). All specimens withstood fatigue application. While the effect of fatigue was not significant in any group (p = 0.714), the choice of material had a significant effect (p < 0.001). Material FL recorded the highest failure loads, followed by Z-ST, Z-HT and RL, both with and without fatigue application. Taken together, all tested FDP material combinations survived chewing forces that exceeded physiological levels. Bi-Layer FL and monolithic Z-ST showed the highest resilience and might serve as reliable prosthetic reconstruction concepts for 3-unit FDPs on ceramic implants. [ABSTRACT FROM AUTHOR]

Objectives: To compare the impact of intaglio surface treatments - airborne particle abrasion and hydrofluoric acid (HF) etching - of feldspar ceramic (FEL) crowns on the fracture load (FL) and to investigate the effects of abutment materials and artificial aging. The aim was to assess whether etching could be replaced by an alternative surface roughening method., Materials and Methods: FEL crowns had their intaglio surfaces either abraded (25 µm Al 2 O 3 , 0.1 MPa), etched (HF, 60 s), or untreated and then bonded to CoCrMo- and polymer-abutments. FL was measured for non-aged and aged (1.2 million mastication cycles) specimens. Data were analyzed using, Weibull modulus, two-/one-way ANOVA with Tukey HSD-post-hoc-test, t-tests, and TOST equivalence (p < 0.05)., Results: For crowns bonded to CoCrMo abutments, aging affected the FL and Weibull modulus, but pretreatment methods did not. For initial specimens, airborne abraded and etched crowns were equivalent within a 400N bound, however, for aged specimens, equivalence was inconclusive. For crowns bonded to polymer-abutments, pretreatment and aging influenced the FL. Etching decreased the initial FL by over 420N compared to airborne abraded and untreated specimens. After aging, untreated crowns' FL decreased by 528N, while airborne abraded and etched specimens showed no aging effect., Conclusions: Airborne particle abrasion of FEL crowns' intaglio surfaces did not negatively impact FL and was comparable to etched crowns. Conclusions regarding pretreatment methods and aging differed between CoCrMo- and polymer-abutments., Clinical Relevance: Airborne particle abrasion may be an alternative procedure for the intaglio surface treatment of FEL crowns prior bonding., Competing Interests: Declarations. Conflicts of interest: The authors declare that there are no conflicts of interest related to this publication. Ethical approval: This article does not contain any studies with human participants or animals performed by any of the authors. Informed consent: For this type of study, formal consent was not required., (© 2025. The Author(s).)

Purpose: The current study aimed to compare modified Polyether-ether-ketone's fracture resistance and failure mode versus lithium disilicate glass-ceramic endocrowns., Materials and Methods: A total of 16 butt-joint endocrown specimens on mandibular second molar teeth were fabricated and divided into two equivalent groups; Pressable modified Polyether-ether-ketone (PEEK) (BioHPP ® ) and Pressable lithium disilicate glass ceramic (IPS e.max ® Press). A computer-aided design/computer-aided manufacturing system was used to digitally create and milled wax patterns. Final restorations were cemented each to its corresponding prepared tooth. Thermomechanical cycling loading representing one year of clinical service was done in a chewing simulator. Fracture resistance was evaluated utilizing a universal testing machine. The failure mode was evaluated by inspecting fractured surfaces using a Stereomicroscope and further examined by a Scanning Electron Microscope (SEM) amongst both groups., Results: A statistically significant variation in fracture resistance was recorded with a mean load of (2762.96 ± 216.15 N) for modified PEEK and (2175.91 ± 267.72 N) for lithium disilicate glass-ceramic endocrowns., Conclusion: Modified PEEK endocrowns have higher fracture resistance than lithium disilicate glass-ceramic endocrowns. Moreover, the likeliness of catastrophic fracture in molars receiving endodontic treatment restored by modified PEEK is less than teeth restored with lithium disilicate glass ceramics., Competing Interests: Declarations. Ethics approval and consent to participate: This study was approved by the Ethics Committee from the Faculty of Dental Medicine, Al-Azhar University, Cairo, Egypt. (Ethical code: 669/3786). Considering the retrospective nature of the study, the informed consent to participate is waived by the same ethics committee. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Objective: This study aimed to assess the fracture resistance of chairside computer assisted design and computer assisted manufacturing (CAD-CAM) lithium disilicate partial and full-coverage crowns and veneers for maxillary canines., Methods and Materials: Forty-eight restorations for maxillary right canines (12 per group) were designed as follows: (1) partial crown with finish line in the upper middle third; (2) partial crown with finish line in the lower middle third; (3) traditional labial veneer; and (4) traditional full-coverage crown. Restorations were fabricated out of lithium disilicate (Amber Mill, Hassbio) using a chairside CAD-CAM system (Cerec Dentsply Sirona). Partial and full crowns and veneers were treated with a primer system (Monobond Plus, Ivoclar Vivadent) and cemented using dual-cure resin cement (Variolink Esthetic, Ivoclar Vivadent) and cemented to printed resin dies. Subsequently, the restorations were subjected to 10,000 thermocycles between 5°C and 55°C with a dwell time of 30 seconds. The restorations were then loaded axially on the incisal edge in compression to fracture with a flat indenter., Results: Full-coverage crowns displayed the highest fracture resistance (809±28.57 N) followed by partial crowns with finish line in lower third (649±21.74 N) and crowns with finish line in upper third (421±17.46 N). Veneers displayed the lowest fracture resistance values (259±15.69 N)., Conclusions: The fracture resistance of partial and full-coverage crowns and veneers was significantly influenced by the design. Full coverage crowns displayed the highest fracture resistance and partial crowns showed higher fracture resistance than traditional veneers., (©Operative Dentistry, 2025.)

The "all-on-four" treatment modality is a treatment in which four implants are surgically placed in the completely edentulous jaw in order to restore immediately loaded implant supported fixed restoration. The aim of the present study was to compare clinical, radiological and prosthetic outcomes of immediately loaded maxillary and mandibular four implant supported cross-arch fixed denture prosthesis. A total of 112 edentulous patients who were rehabilitated for their complete maxillary and mandibular edentulism using All-on-four concept between January 2010 to August 2012 in four private dental clinics were included in this study for retrieve their data for marginal bone loss, implant survival rate, and prosthetic complication for a period of 8 years of follow-up. A total of 12 patients lost 18 implants, provided a cumulative survival estimate of 97.99% at 8 years in the maxillary arch implants in 8 years of follow-up. After 1 year of follow-up, the mean bone loss with in comparison to baseline at implant level was 1.14 ± 0.86 (mean ± SD), and after 8 years it was 1.63 ± 1.24. In the maxillary arch the marginal bone loss was more when compared to mandibular arch, it showed 1.58 ± 1.22 and 1.89 ± 1.18 for 1 year and 8 years, respectively, for the implants in the maxillary arch. Cumulative implant survival rate recorded in 8 years of follow-up was 97.99%. With a prosthetic survival rate of 78.6%, The prosthetic failure was mainly due to the type of restoration (acrylic wrap-around).

Dental implants are integral in replacing missing teeth, providing durability and natural aesthetics through osseointegration-a process where the implant fuses with the jawbone to support a prosthesis. However, screw loosening presents significant challenges, potentially leading to implant failure, bone loss, and peri-implantitis. Contributing factors include micro-leakage, settling effects, loss of preload, abutment angulation, and inadequate torque application. Addressing these issues through proper torque management, anti-rotation features, and retightening protocols is crucial for implant longevity and success. This study outlines key causes and solutions for screw loosening in dental implants.

Objectives: This systematic review aimed to determine whether bioactive resin materials can prevent secondary caries or enhance the longevity of direct posterior restorations., Data Sources: The protocol was registered in PROSPERO (CRD42024561179). The review followed PRISMA guidelines, utilizing a PICO framework. Studies were identified through searches in six databases (PubMed, Scopus, Cochrane, Embase, Scielo, Web of Science) up to May 2024., Study Selection: Two independent reviewers applied inclusion criteria, selecting randomized clinical trials evaluating bioactive resin composites in restorative dentistry. Data were extracted into pre-designed forms, and article quality was assessed using the CONSORT, RoB 2, and GRADE tools. Meta-analyses focused on secondary caries incidence and restoration longevity using USPHS and FDI criteria., Results: Of 1,565 articles identified, 10 met the inclusion criteria. These studies, conducted in five countries, included 411 participants with follow-up periods ranging from 1 to 8 years. Materials evaluated included ACTIVA™ BioACTIVE, Giomer, and Cention N. Meta-analysis found no statistically significant differences between bioactive and conventional resin composites in preventing secondary caries or reducing retention loss (p > 0.05), the two primary outcomes considered in this review for assessing restoration longevity. Subgroup analysis showed no differences between follow-up periods., Conclusions: Bioactive materials demonstrated similar clinical performance to conventional composites in preventing secondary caries and retaining restorations, offering no additional benefit in enhancing the longevity of direct posterior restorations., Clinical Significance: This review provides evidence that bioactive resin materials offer no significant clinical advantage over traditional composites, guiding (or informing) clinicians in (or about) material selection for restorative treatments., 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.)

Objectives: This study investigates longevity of glass ionomer restorations in an older adult population., Methods: This was a retrospective study based on clinical records. Patient records for 3,665 restorations in 1,777 adults 65 or older who had received a restoration between 12th July 2016 and 20th October 2022 were extracted from the electronic dental records system of the University of Iowa College of Dentistry and Dental Clinics. The data were analyzed to determine the influence of patient factors and restorative material on restoration longevity. Single variable and multiple variable survival models were created., Results: Many variables that showed a statistically significant influence on restoration longevity in the single variable survival models and did not show such an influence in the multivariable model, indicating the effect of these variables is explained when other factors are controlled for. In particular, patient age at the time of restoration showed no significant influence in the multivariable model, and no medical factor had a statistically significant influence. The restorative material did show a significant influence in the multivariable model; using the resin-modified glass ionomer restorative (Fuji II LC) as a reference, the conventional glass ionomer restorative (Fuji IX) had a hazard ratio of 2.0 (p = 0.011), and the coated-conventional glass ionomer restorative (Equia) had a hazard ratio of 2.8 (p < 0.001)., Significance: Resin-modified glass ionomer restorations may have superior longevity for older adults than conventional and coated-conventional glass ionomer restorations., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This study was funded by the Nakao Foundation, which in turn was established by GC, the manufacturer of the restorative materials investigated., (Copyright © 2024. Published by Elsevier Ltd.)

Objectives: To conduct a systematic review and network meta-analysis (NMA) to answer whether endocrown restorations have similar mechanical behavior than other traditional core-crown systems with or without intracanal posts for the rehabilitation of anterior endodontically treated teeth., Methods: The review followed the PRISMA Extension Statement for NMA. Studies were identified by a systematic search to select reports on endocrown restorations in anterior teeth. A search was performed in PubMed (MEDLINE), Scopus, Web of Science, Embase, SciELO, and LILACS databases. Articles evaluating mechanical performance through in vitro and finite element analysis (FEA) studies were selected and the risk of bias was assessed using the RoBDEMAT and ROBFEAD tools, respectively. The data were analyzed qualitatively and quantitatively through NMA using the MetaInsight tool., Results: Eleven articles were included (eight in vitro and three with FEA design). Six in vitro studies were evaluated using NMA. Composite resin endocrowns showed greater load-to-fracture and lower occurrence of catastrophic failures than traditional restorations. Combining glass fiber post with composite restoration also showed good strength behavior. Regarding FEA studies, two out of three studies showed a more homogeneous distribution of stress for the endocrown group., Significance: Endocrowns performed similarly to or better than conventional restorative strategies, with composite resin being the most recommended material of choice. The rehabilitation of endodontically treated anterior teeth with extensive coronal destruction is typically challenging for the dentist, and there is still no consensus in the literature that provides conclusive answers for choosing the appropriate material and restorative strategy. Exploring new techniques and materials that make this procedure easier for the dentist and guarantee good results is paramount., Competing Interests: Conflict of interest The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Predicting how tooth and dental material bonds perform in the mouth requires a deep understanding of degrading factors. Yet, this understanding is incomplete, leading to significant uncertainties in designing and evaluating new dental adhesives. The durability of dental bonding interfaces in the oral microenvironment is compromised by bacterial acids, salivary enzymes, and masticatory fatigue. These factors degrade the bond between dental resins and tooth surfaces, making the strength of these bonds difficult to predict. Traditionally studied separately, a combined kinetic analysis of these interactions could enhance our understanding and improvement of dental adhesive durability. To address this issue, we developed and validated an original model to evaluate the bond strength of dental restorations using realistic environments that consider the different mechanical, chemical, and biological degradative challenges working simultaneously: bacteria, salivary esterases, and cyclic loading. We herein describe a comprehensive investigation on dissociating the factors that degrade the bond strength of dental restorations. Our results showed that cariogenic bacteria are the number one factor contributing to the degradation of the bonded interface, followed by cyclic loading and salivary esterases. When tested in combinatorial mode, negative and positive synergies towards the degradation of the interface were observed. Masticatory loads (i.e., cycling loading) enhanced the lactic acid bacterial production and the area occupied by the biofilm at the bonding interface, resulting in more damage at the interface and a reduction of 73 % in bond strength compared to no-degraded samples. Salivary enzymes also produced bond degradation caused by changes in the chemical composition of the resin/adhesive. However, the degradation rates are slowed compared to the bacteria and cyclic loading. These results demonstrate that our synergetic model could guide the design of new dental adhesives for biological applications without laborious trial-and-error experimentation., 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 B.V. All rights reserved.)

Implant abutment fractures are an uncommon mechanical complication, and the removal of the abutment fragment and replacement with a new prosthesis is the best solution. However, successful retrieval of the fractured abutment fragment from the implant is challenging, and effective rescue kits are lacking. This clinical report describes the retrieval of a fractured implant abutment in a conical connection implant using a modified manufacturer-specific instrument., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Studies on the fracture performance of a recently introduced computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate ceramic containing virgilite with different cements are lacking., Purpose: The purpose of this in vitro study was to evaluate the fracture resistance of crowns made of a recently introduced chairside CAD-CAM lithium disilicate containing virgilite cemented with different types of adhesive luting cement., Material and Methods: Sixty complete coverage crowns for a maxillary right central incisor were milled out of a lithium disilicate with virgilite (CEREC Tessera) (n=48) and a traditional lithium disilicate (e.max CAD) (n=12) using a chairside CAD-CAM system (Primescan). The central incisor tooth preparation included a 1.5-mm incisal reduction, a 1.0-mm axial reduction, and a 1.0-mm chamfer finish line. The restorations were bonded with different types of resin cement to 3D printed dies of the tooth preparation and were divided into 5 groups (n=12 per group): e.max CAD with Multilink Automix (E.Mu); Tessera with Multilink Automix (T.Mu); Tessera with Calibra (T.Ca); Tessera with Unicem (T.Un); and Tessera with Speedcem (T.Sp). The cemented restorations were stored in water for 30 days and then loaded until they were fractured in compression. The load at fracture was analyzed with a 1-way analysis of variance (ANOVA) and the honestly significant difference (HSD) Tukey test (α=.05)., Results: The mean fracture resistance of traditional lithium disilicate and virgilite lithium disilicate anterior crowns significantly differed depending on the type of resin cement used (P<.05). Group E.Mu displayed the highest values (946.35 ±155 N), followed by group T.Un (819.59 ±232 N), group T.Sp (675.52 ±153 N), and group T.Mu (656.95 ±193 N). The lowest values were displayed by group T.Ca (567.94 ±184 N)., Conclusions: The fracture resistance of lithium disilicate containing virgilite and traditional lithium disilicate crowns cemented with the same cement displayed statistically similar values. However, significant differences were observed when the virgilite lithium disilicate crowns were cemented with different types of adhesive luting cement. The crowns in the T.Ca group displayed the lowest fracture resistance., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objective: Based on the critical role of implant length and placement timing in treatment success, this study aimed to compare clinical outcomes (implant failure, marginal bone loss, biological and mechanical complications) between short implants (4-8 mm) versus long implants (≥ 8 mm) with sinus floor elevation, and between delayed versus immediate placement of long implants in the posterior maxilla., Methods: This network meta-analysis was prospectively registered in the PROSPERO database (CRD42023495027). Adhering to PRISMA-NMA guidelines, we systematically reviewed eligible studies from January 2014 to November 2024 was conducted across major databases, such as the Cochrane Library, PubMed, Embase, Scopus and Web of Science. The main focus of this NMA was to determine the rate of implant failure, as well as to assess marginal bone loss and the occurrence of biological and mechanical complications related to the implants., Results: Data from 17 studies, involving 1,076 patients and 1,751 implants, was collected and examined. Long implants have lower failure rates (OR = 1.26; 95% CI = 0.53, 3.00) and short dental implants showed a trend towards lower biological (OR = 0.47; 95% CI = 0.19, 1.18) and mechanical (OR = 0.94; 95% CI = 0.45, 1.94) complications rates, although this trend was not statistically significant. Additionally, compared to longer implants, short implants resulted in a significant reduction in marginal bone loss, regardless of whether long implants were immediately (MD=-0.17; 95%CI: -0.29, -0.05) or delayed (MD = 0.35; 95%CI: 0.05, 0.64) placed following sinus floor elevation. The analysis of cumulative ranking probabilities revealed that delayed placement of long implants with SFE demonstrated the highest efficacy in reducing implant failure (73.9%). SIs were found to excel in reducing marginal bone loss (88.7%) and biological complications (88.2%%), while short implants with SFE proved to be the most effective in preventing mechanical complications (66.0%%)., Conclusion: Short implants achieved comparable clinical outcomes to long implants with sinus floor elevation in posterior maxilla with limited vertical bone height. Given the limitations of the network meta-analysis and included studies, treatment selection should be individualized based on specific patient conditions., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Lithium disilicate occlusal veneers are popular for minimally invasive posterior teeth restoration. The aim of this study was to compare the fatigue resistance and crack pattern of lithium disilicate occlusal veneers fabricated using pressing and milling techniques with varying thicknesses., Methods: Sixty lithium disilicate discs, representing occlusal veneers, were divided into four groups (n = 15) based on processing technique (IPS e.max Press or IPS e.max CAD) and thickness (0.5 or 0.8 mm). A step-stress fatigue test was applied with axial loading, consisting of 10,000 cycles/step with a step size of 50 N until failure. Fractographic analysis was performed using SEM. Statistical analysis was performed using the Kaplan-Meier test, Mantel-Cox test, and Weibull analysis., Results: Both processing techniques resulted in similar fatigue resistances at 0.5 mm and 0.8 mm thicknesses. However, the 0.8 mm lithium disilicate restorations showed a significantly higher survival rate than the 0.5 mm lithium disilicate restorations (log-rank tests, χ 2  = 58.6; df = 3; P < 0.001). Fractographic analysis revealed radial cracks originating from defects on the ceramic surface at the cementing interface, extending towards the occlusal surface., Conclusions: At 0.5 mm or 0.8 mm material thickness, the processing technique did not affect the fatigue resistance or crack patterns of the lithium disilicate occlusal veneers. However, the lithium disilicate with a thickness of 0.8 mm exhibited a superior survival probability compared to that with a thickness of 0.5 mm., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Objectives: Clinical data on the performance of double-crown-retained removable dental prostheses (dcRDPs), especially beyond university studies, are rare. The objective of this retrospective clinical study was to evaluate the survival and complication-freeness probabilities of dcRDPs and to identify risk factors for failure and complications in a dental practice setting., Materials and Methods: Anonymized practice data of 174 patients (56.9% female) fitted with a total of 213 dcRDPs (mean of 3.3 abutment teeth per dcRDP) were evaluated up to 11 years after prothesis placement (mean observation time of 3.9 years). Probabilities of survival and complication freeness were calculated on the prosthesis- and abutment level and visualized using the Kaplan-Meier method. Factors influencing failure and complications were computed using Cox regression analyses (R Ver. 7; alpha < 0.05)., Results: During our observation period, 39 (18%) of the dcRDPs failed. The mean (95% CI) overall survival was 94% (90-97%) after 2 years and 86% (80-92%) after 5 years. DcRDP survival correlated with lower patient age and more abutment teeth (P < 0.05), while other analyzed factors did not. The probability of absence of prosthesis-related complications was 92% after 2 years and 80% after 5 years. The probability of no technical complications of abutments (teeth/implants) was 85% after 2 years and 78% after 5 years, and the probability of no biological complications was 87% after 2 years and 72% after 5 years. In total, 141 dcRDPs (66.2%) faced at least one complication during the observation period., Conclusions: Double-crown-retained prostheses fitted in a dental practice had acceptable mid-term survival rates and common technical and biological complications that were frequently easily manageable. However, prosthesis performance depended on the quality and number of abutment teeth/implants. Within the limitations of this retrospective analysis, the outcomes we observed in a dental practice are comparable to, albeit slightly worse than, those found in university studies., Clinical Relevance: Evaluation of the clinical performance of dcRDPs fitted in a dental practice is important to estimate durability and complication patterns in order to weigh treatment decisions., Competing Interests: Declarations. Ethics approval and consent to participate: All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. This retrospective study used anonymized patient data. Informed consent of participants was therefore not applicable. The local review board of the University of Heidelberg (no. S-136/2023) approved this study. Consent for publication: The manuscript has been read and approved by all the authors. All authors gave consent for publication. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)