Evaluation of the clinical success of direct restorations of endodontically treated posterior teeth in the presence of parafunction: a 12-month pilot study

A comparison of stresses in molar teeth restored with inlays and direct restorations, including polymerization shrinkage of composite resin and tooth loading during mastication

To evaluate interfacial gap and fracture resistance of endodontically treated maxillary premolars, restored with different glass-fiber reinforced materials. Eighty-four extracted intact premolars were endodontically treated and MOD cavities prepared. Specimens were divided into 7 groups (n = 12 for each) as follows: sound teeth (G1); no restoration (G2); direct composite restoration with fiber-reinforced composite (everX Posterior GC) (G3); direct composite restoration (Filtek Supreme XTE, 3M Oral Care; "FSXTE") (G4); a horizontal layer of high-viscosity flowable composite (G-ænial Flow, GC) was placed on the pulp chamber floor, 10 mm x 3 mm glass fibers (everStick NET, GC) were inserted into the cavity (G5); same procedure as in group 5 except the direct restoration was made incrementally with FSXTE (3M Oral Care) (G6); composite overlays were placed (G7). Specimens were scanned with micro-CT to evaluate 3D interfacial gaps before and after chewing simulation using Mimics software to calculate voids between restoration and tooth (dentin and enamel). These data (in mm3) were collected for statistical analysis. Thereafter, specimens were loaded to fracture using a universal testing machine. Maximum breaking loads were recorded in Newton (N). The data obtained were analyzed using two-way ANOVA and post-hoc Tukey's test (p < 0.05). ANOVA showed that horizontal glass-fiber insertions statistically significantly reduced interfacial gaps after chewing simulation. No differences in fracture resistance were found between Filtek Supreme XTE and everX Posterior; moreover, glass-fiber insertion did not significantly improve fracture resistance in either case. Composite overlays achieved significantly better fracture toughness than did direct restorations. For the direct restoration of endodontically treated premolars, the insertion of glass fibers into direct composite restorations was unable to guarantee a significant increase in the fracture resistance or a significant change in the fracture pattern. However, it significantly reduced interfacial gap volume after cycling fatigue.

To compare the survival and success rates of direct composite resin restorations versus metal-ceramic crowns in endodontically treated molar teeth with minimal structure loss. This clinical trial included 60 participants, each with an endodontically treated molar with at least three remaining axial walls (>2mm). Half of the participants received direct restorations, and half metal-ceramic crowns. USPHS criteria were used at baseline and annually for three years. Kaplan-Meier and log-rank tests analyzed survival/success rates. Cox regression evaluated predictors, and Mann-Whitney U and Wilcoxon tests compared USPHS outcomes. Fifty-three participants completed the 3-year follow-up (7 dropped out). The three-year survival rate for crowns was 93.3 % (95 % CI: 78.7 %-98.2 %), while the direct restoration group had 76.7 % (95 % CI: 59.1 %-88.2 %). The difference was insignificant (P = 0.061). Success rates were also comparable (crowns=90.0 % vs. restorations=76.7 %; P = 0.138). Bruxism significantly predicted failure (HR=12.8, 95 % CI: 1.2-133.3, P = 0.032). Direct restorations had worse outcomes than crowns regarding caries (P = 0.018), surface texture (P = 0.019), and marginal integrity (P = 0.006). Crowns had worse outcomes in terms of periodontal indices (P = 0.032) and presence of periapical infection (P = 0.023). Over time, direct restorations significantly deteriorated in terms of caries (P = 0.041), margin discoloration (P = 0.007), margin integrity (P = 0.026), and fracture (P = 0.034), while crowns showed no significant changes. For endodontically treated molars with minimal structure loss, both direct composite resin restorations and full crowns demonstrated similar survival and success after 3 years of function. However, crowns were more predictable, especially for bruxers. Direct restorations may suit cases with lower occlusal loads, endodontic monitoring, or budget constraints. This study showed similar 3-year survival/success rates of direct composite restorations compared to metal-ceramic crowns in restoring endodontically treated molar teeth with minimal structural loss. These results indicate that direct restorations may be suitable alternatives for molars with minimal structural loss, particularly in cases with reduced occlusal loads, a need for endodontic monitoring, or financial limitations.

Three-year clinical evaluation of direct and indirect composite restorations in posterior teeth

Besides prosthetic and indirect, laboratory-produced restorations, the focus of dental therapy is increasingly on restorative measures and direct restorations as minimally invasive treatment concepts. Thus, the use of direct composite restorations with modern restorative materials for the shaping and recontouring of teeth in combination with orthodontic treatment offers a diversified, extensive sphere of application. The aim of the study was to demonstrate applications for direct composite restorations with reference to selected cases. The composites used were hybrid composites, which offer increased abrasion resistance and color stability and are applied incrementally. Special attention was paid to the shape, color and structure of the tooth. The case reports present patients in whom relatively narrow or peg-shaped teeth were built up with composite to correct various tooth size discrepancies or cuspids were recontoured by means of direct composite restorations following orthodontic space closure in cases with missing lateral incisors. Similarly, space closure was achieved using orthodontically repositioned lateral incisors recontoured to resemble central incisors after traumatic loss of upper central incisors. Finally, direct composite restorations were used for retention following completion of orthodontic treatment. Observations over recent years confirm the stability of composites in both form and color, as well as their ability to maintain gingival health. Our case reports demonstrate that, subject to a corresponding indication, recontouring single teeth using direct composite restorations can optimize orthodontic treatment results.

Objectives: Contemporary resin composites used in large restorations still demonstrate limitations due to their limited mechanical properties. Resin composite reinforced with short randomly oriented glass fibres exhibit improved mechanical properties regarding flexural strength, fracture toughness and polymerisation shrinkage in comparison to particulate filler composite (PFC). Therefore short fibre-reinforced composite (SFRC) can be beneficial in stress-bearing applications. The aim of this case series is to assess the usefulness of SFRC within different restorative indications. Materials and Methods: Four patients presenting different restorative problems were selected. Direct composite restorations were used in each situation: a cusp-replacement, a post-and-core, an endocrown and a fibre-reinforced composite resin-bonded fixed dental prosthesis. For all indications biomimetic principles were applied i.e. dentin was replaced by SFRC that was entirely embedded with enamel-replacing PFC. Results: Handling and aesthetic characteristics of SFRC proved to be appropriate for application in biomimetic restorations. SFRC easily adapted to the dentine by additional use of a small amount of low viscosity PFC and did not interfere with the aesthetic outcome of the restorations. The obtained clinical results were highly assessed by each patient. No restoration failed after six months of function. Conclusion: It seems reasonable to use SFRC in a biomimetic treatment approach for stress-bearing applications. The benefits of SFRC-based biomimetic direct composite restorations needs to be investigated in a properly designed long-term random clinical trial. Clinical Relevance: The use of SFRC as dentin replacement within a biomimetic treatment approach provides a rationale for extended use of direct resin composite restorations in stress-bearing applications.

Objective: Despite the incremental build-up of resin composite restorations, their polymerization shrinkage during curing presents a serious problem. Indirect composite resin systems represent an alternative in overcoming some of the deficiencies of direct composite restorations. The hypothesis of the present study states that the clinical performance of restorations may be affected by different generation and application techniques. Study Design: Sixty restorations (20 DI system (Coltène/Whaledent AG, Altstätten, Switzerland) composite inlays, 20 Tescera ATL system (BISCO Inc. Schaumburg, Illinois, USA) composite inlays, and 20 direct composites) were applied to premolar teeth in 49 patients. Restorations were clinically evaluated by two examiners. Data were analyzed using the Kruskal-Wallis, Mann-Whitney U, Wilcoxon Signed Ranks, and X2 tests. Results: The Tescera ATL system performed significantly better than both direct composite restorations (p<0.001) and DI system (p<0.05). Conclusion: Within the limitations of this 3-year clinical study, indirect resin restorations showed better scores than direct restorations. In addition, the Tescera ATL system was found to be more successful than the DI system and direct composite restorations. Key words:Composite, inlay, direct composite restorations, indirect composite restorations.

Clinical Performance and Epidemiologic Aspects of Fractured Anterior Teeth Restored with a Composite Resin: A Two-Year Clinical Study.

Endodontically-treated teeth are weaker than vital teeth due to extensive missing sound tooth structure and the endodontic treatment. The restoration choice for an endodontic treatment tooth (ETT) determines the ETT’s survival. This study aims to investigate the fracture resistance and mode of direct composite restoration and direct composite onlay with cuspal coverage on endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. Twenty sound upper premolars were collected from local dental clinics, mounted in cold-cure acrylic and stored in normal saline. Teeth were subjected to root canal treatment (RCT), followed by MOD cavity preparation. The teeth were randomly and equally divided into two groups (Groups A and B). Group A (n = 10) were restored with direct composite restoration, whereas Group B (n = 10) were prepared occlusally and restored with direct composite onlay restoration. All teeth were subjected to a compressive axial load test using a universal testing machine (Instron 3369, United State) with a metal ball sized 4 mm at 1mm/min of crosshead speed until a fracture occurred. The fracture mode was analysed under a stereomicroscope with 0.68 magnifications. A statistical analysis of fracture resistance and fracture mode was performed using a paired T-test. The mean fracture resistance value was 431.37 N for group A and 1158.34 N for group B, with a statistically significant difference (p&lt; 0.05) between these two groups. Endodontically-treated upper premolar with MOD cavities restored with direct composite onlay restoration exhibited higher fracture resistance than direct composite restoration. In addition, the mode of fractures was not affected by the types of restoration.

Two-year clinical evaluation of direct and indirect composite restorations in posterior teeth

Direct resin composite inlays/onlays: an 11 year follow-up

In the clinic, it is crucial to be aware of the long-term clinical efficacy of restoration techniques, such as direct and indirect, when restoring molar teeth. This randomized controlled trial aimed to evaluate the clinical performance of direct and indirect restorations in Class I cavities in molar teeth. Randomization was achieved by flipping a coin to determine which tooth would receive the direct restoration, with the other tooth receiving an indirect restoration. The study was comprised of 27 patients, with an average age of 34.16 (range, 24-54) years. A total of 54 class I restorations were made, 27 of which were direct restorations and 27 were indirect restorations. One direct and one indirect Class I restoration was performed on each patient. A microhybrid universal composite (Aelite All-Purpose Body, Bisco) was used for direct restorations, and a reinforced microfill composite system (Tescera Indirect Composite System Body, Bisco) was used for indirect restorations. The restorations were assessed at baseline and at 1, 2, and 10-year recalls using the modified USPHS criteria. The results were analyzed statistically using the Friedman test, Mann-Whitney U test, and Dunn's post hoc test. After 10 years, the success rate was 85.2% for direct restorations (p = 0.007) and 96.3% for indirect restorations (p = 0.39). Four direct restorations failed because of caries (p = 0.007), and one indirect restoration failed due to the need for crown restoration (p = 0.39). The failure rate of direct restorations was higher than that of indirect restorations (p = 0.043). Except for caries, for any evaluation criterion, no statistically significant difference (p > 0.05) was detected between indirect and direct restorations among all evaluation periods. Both direct and indirect restorations have demonstrated satisfactory success rates after 10 years. The primary cause of restoration failure in direct restorations was caries. Although indirect restoration options give excellent results for Class I cavities at the end of 10 years, direct restorations may be a suitable alternative for Class I cavities due to their several advantages. At the end of 10 years, it can be said that both direct and indirect restorations may be preferred in Class I cavities. ClinicalTrials.gov identifier NCT07081529. Registered on July 22, 2025. Retrospectively registered.

The aim of this systematic review and meta-analysis was to compare static compression forces between direct composite resin restorations and indirect restorations for posterior teeth. All studies comparing mechanical properties of direct versus indirect restorations of posterior teeth were included from 2007 up to February 2024. A meta-analysis was conducted for static compression fracture resistance. Medline, Central, and Embase databases were screened. Twenty-four articles were included in the qualitative synthesis, and sixteen studies were finally included in the quantitative synthesis. There was no difference in terms of fracture resistance between direct and indirect restorations for posterior teeth (p = 0.16 for direct and indirect composite resin restorations and p = 0.87 for direct composite resin restorations and indirect ceramic restorations). Also, sub-group analysis with or without cusp coverage in each group revealed no discernable difference. Based on this study, it can be concluded that the choice between direct and indirect restoration approaches may not significantly impact fracture resistance outcomes. There was no statically significant difference between direct and indirect restorations for posterior teeth in all cases of restorations with or without cusp coverage and no matter the used materials. However, to better evaluate these materials, further studies are warranted.

The purpose of this case series study was to evaluate posterior single-tooth implant survival and the long-term conditions of the adjacent teeth. A retrospective evaluation of 1,162 consecutive patients with a single missing posterior tooth treated with 1,377 external hex implants supporting 1,365 restorations surrounded by natural teeth over a 1- to 10-year period was reviewed from four private offices. Implant survival data were collected relative to stage I to stage II healing, stage II to prosthesis delivery, and prosthesis delivery to up to 10 years of follow-up. Long-term adjacent tooth conditions were assessed, including decay, endodontic therapy (root canal therapy [RCT]), and/or extraction during the follow-up period. Of the 1,377 implants inserted, there were 11 surgical failures from stage I to stage II healing. There was one failure from stage II healing to prosthesis delivery. There were two prosthetic-phase failures. The surgical success rate was 99.2%, whereas the overall survival rate was 98.9% at an average of 61 months of follow-up (range, 12 to 125 months). A total of 2,589 adjacent teeth were followed during the study. No natural adjacent tooth was lost during this period. Interproximal decay developed in 129 adjacent teeth (5%), and nine adjacent teeth required RCT (0.4%) as a result of decay or restoration. The use of single-tooth implants as replacements for posterior missing teeth is a viable long-term treatment. Adjacent natural teeth complications are minimal for as long as 10 years after implant insertion.

The restoration of endodontically treated teeth is a critical aspect of dental practice, with the choice between direct and indirect restoration techniques being central to optimizing clinical outcomes. Direct restorations, such as composite resins, offer advantages in terms of cost, time efficiency, and preservation of tooth structure. However, their long-term performance, particularly in posterior teeth, may be compromised by issues such as marginal leakage, wear, and discoloration. Indirect restorations, including crowns, onlays, and inlays, provide enhanced durability, fracture resistance, and aesthetic outcomes, particularly for teeth that have undergone significant structural loss. These restorations, often made from ceramics or metals, offer superior longevity but come with higher costs and longer treatment times. The aesthetic performance of restorations plays a significant role in patient satisfaction. While direct restorations allow for immediate aesthetic adjustments and are generally more affordable, they may suffer from discoloration and wear over time. Indirect restorations, particularly porcelain-based options, offer better color stability and natural appearance, making them a preferred choice for patients with high aesthetic demands. Cost-effectiveness is another critical factor influencing clinical decision-making. While direct restorations are more affordable initially, their long-term cost-effectiveness may be compromised by the need for repairs or replacements. Indirect restorations, despite their higher upfront cost, often prove to be more economical in the long run due to their durability and reduced need for maintenance. The decision between direct and indirect restoration techniques should be individualized, considering factors such as tooth location, the extent of damage, aesthetic requirements, and financial constraints. A comprehensive evaluation of these factors, along with clear communication with the patient, is essential for achieving optimal clinical outcomes. Indirect restorations generally offer better long-term performance, particularly for heavily compromised teeth, while direct restorations remain a viable option for cases where cost and time efficiency are prioritized.