Survival rates against fracture of endodontically treated posterior teeth restored with full-coverage crowns or resin composite restorations: a systematic review

Clinical performance of polyethylenefiber reinforced resin composite restorations in endodontically treated teeth: (a randomized controlled clinical trial)

AIM

The purpose of this study was to evaluate the performance of polyethylene fiber reinforced resin composite fillings compared to bulk fill resin composite fillings in endodontically treated teeth over a two-year monitoring period.

METHOD

A total of 240 individuals with endodontically treated lower molars and a moderate amount of tooth structure were divided into two equal groups of 120 each. One group received polyethylene fiber reinforced bulk fill resin composite restorations while the other group received only bulk fill resin composite restorations, both applied as per manufacturer guidelines. Two proficient experienced blinded assessors assessed the restorations using modified USPHS criteria at baseline, 6, 12, and 24 months.

STATISTICAL ANALYSIS USED

Data analysis involved the utilization of Mann-Whitney U, Friedman's test, and Nemenyi post hoc test, with age data being displayed as mean and standard deviation. The significance level was established as p < 0.05, and R software was utilized for statistical analysis.

RESULTS

There were no notable distinctions in any parameters or scores between the intervention and comparator groups at various time points. Alpha scores were present for retention, gross fracture, and secondary caries at all follow up intervals.

CONCLUSION

Both direct resin composite restorations reinforced with polyethylene fibers and direct bulk fill resin composite restorations placed in endodontically treated molars with moderate remaining tooth structure demonstrated satisfactory clinical outcomes during a 24-month follow-up period.

CLINICAL RELEVANCE

Bulk fill resin composites directly placed in endodontically treated molars with moderate remaining tooth structure showed promise as a treatment option over a two-year period.

CLINICAL TRIAL REGISTRATION

(06-01-2022) on https://ClinicalTrials.gov with the ID (NCT05180903).

Direct Versus Indirect Treatment Options of Endodontically Treated Posterior Teeth: A Narrative Review

One of the controversial topics in dentistry is restoring endodontically treated posterior teeth. Most posterior teeth that undergo endodontic treatment are subjected to a high rate of fracture due to excessive amount of loss of tooth structure. The aim of this review is to evaluate and compare the restorative and prosthetic treatment options to provide clinical recommendations for restoring endodontically treated posterior teeth. Both Medline on PubMed and Google Scholar were utilized for the search. The terms on our keyword list were "crown," "onlay," "endo-crown," "amalgam," and "composite," with the time frame from 1977 to 2024. We also examined the reference lists of potentially relevant papers for any recent review articles. Our analysis examined review articles found through computerized searches, along with relevant citations from the bibliographies of those studies. This review will focus on the dental restorative options and the amount of remaining tooth structure in determining the final restoration of an endodontically treated posterior tooth. This narrative review addresses different treatment options for endodontically treated posterior teeth based on the amount of remaining tooth structure. In addition, it compares the survival rate and the limitations among direct and indirect restorations.

Factors influencing the clinical performance of the restoration of endodontically treated teeth: An assessment of systematic reviews of clinical studies

STATEMENT OF PROBLEM

How best to restore endodontically treated teeth is still unclear because many types of material and techniques are involved.

PURPOSE

The purpose of this overview of systematic reviews of clinical studies was to assess the available evidence-based literature on the influence of associated clinical factors on the clinical performance (survival, failure rate, or success) of restored endodontically treated teeth.

MATERIAL AND METHODS

PubMed, Scopus, and Web of Science were searched from inception until September 27, 2021, to identify systematic reviews. Two reviewers independently screened titles, abstracts, and full-text articles, and each reviewer extracted the data of half of the included studies. A single reviewer with an independent verifier completed the quality appraisal. A descriptive analysis of the collected data was made.

RESULTS

A total of 36 systematic reviews fulfilled the inclusion criteria. The factors most assessed were the type of coronal restorative technique (n=22) and type of post (n=22). The results indicated that metal and fiber posts seem to present similar clinical performance, 1-piece endodontic crowns could be a suitable restorative option, there is no evidence to confirm whether single crowns are better or worse than direct restoration, the maintenance of the coronal structure is a fundamental factor, and the ferrule effect is still a controversial topic. Most of the studies (n=30, 81%) presented a final Grading of Recommendations, Assessment, Development and Evaluations (GRADE) rating of "critically low."

CONCLUSIONS

The post type does not appear to influence the clinical performance of restored endodontically treated teeth. However, conclusive evidence to suggest how different materials or techniques for restoring coronal tooth structure affect the clinical performance of such restorations, as well as the impact of the ferrule effect, is still lacking.

One-piece endodontic crown fixed partial denture: Is it possible?

STATEMENT OF PROBLEM

Whether the replacement of a missing tooth with a fixed partial denture supported by an endodontically treated abutment could be improved with 1-piece endodontic crowns is unclear.

PURPOSE

The purpose of the study was to evaluate the mechanical behavior of a fixed partial denture (FPD) according to the preparation of the abutment teeth (1-piece endodontic crown or complete crown) in terms of stress magnitude in the prosthesis, cement layer, and tooth.

MATERIAL AND METHODS

A posterior model with 2 abutment teeth (first molar and first premolar) was modeled with a computer-aided design (CAD) software program for conducting a 3-dimensional finite element analysis (FEA). To replace the missing second premolar, the model was replicated in different possible FPDs according to the abutment preparation design (complete crown [Conventional], 2 1-piece endodontic crowns [EC]) or a 1-piece endodontic crown on one of the abutment teeth (first molar [ECM] and first premolar [ECP]) for a total of 4 designs. All FPDs were in lithium disilicate. The solids were imported to an analysis software program (ANSYS 19.2) in the standard for the exchange of product data (STEP) format. The mechanical properties were considered isotropic and the materials to show linear elastic and homogeneous behavior. An axial load (300 N) was applied at the occlusal surface of the pontic. The results were evaluated by colorimetric stress maps of von Mises and maximum principal stress in the prosthesis, maximum principal stress and shear stresses on the cement layer, and maximum principal stress in the abutment teeth.

RESULTS

The von Mises stresses revealed that all FPD designs behaved similarly and that, considering the maximum principal stress criteria, the pontic was the most stressed region. For the cement layer, the combined designs presented an intermediate behavior, with the ECM more suitable to reducing the stress peak. The conventional preparation allowed less stress concentration in both teeth, and higher stress concentration in the premolar was observed with a 1-piece endodontic crown. The 1-piece endodontic crown decreased the risk of fracture failure. Considering the risk of debonding failure for the prosthesis, the 1-piece endodontic crown preparation was only able to decrease the failure risk when the EC design was used and when only the shear stress was considered.

CONCLUSIONS

Performing 1-piece endodontic crown preparations to retain a 3-unit lithium disilicate FPD is an alternative to conventional complete crown preparations.

Single crown vs. composite for glass fiber post-retained restorations: An 8-year randomized clinical trial

OBJECTIVES

This study aimed to compare the success and survival rates of metal-ceramic crowns and composite resin restorations applied in root filled teeth that received a glass fiber post.

METHODS

A prospective, randomized controlled trial, with equivalent parallel groups was designed. Eighty-two teeth were randomly allocated to the metal-ceramic or composite resin groups. Multivariate Cox regression analysis with shared frailty for patients and Kaplan-Meier curves were performed using success and survival rates (p<0.05).

RESULTS

Seventy-five post-retained restorations (34 metal-ceramic crowns and 41 composite restorations) in 62 patients were analyzed. The median follow-up was 8.1 years [IQR 4.0-9.9]. Twenty-seven failures were observed. Twenty-two failures (81.5 %) were observed in the composite resin group, of which six (27.3 %) were not repairable. Five failures (18.5 %) were observed in the metal-ceramic crown group, of which three (66.6 %) were non-repairable. The cumulative success rate at 8 years was 85.0 % for crowns (AFR=1.31 %) and 43.2 % for composite resins (AFR=6.58 %), while the survival rate was 93.8 % for crowns (AFR=0.52 %) and 97.6 % for composite resins (AFR=0.20 %). Considering the success rates, adjusted multivariate Cox regression showed that composite resin had a Hazard Ratio of 5.07 (95 %CI, 1.99-12.89) greater than the metal-ceramic crown. No significant difference in the failure risk was observed when the survival rates were considered (HR=0.38, 95 %CI (0.10 - 1.44), p = 0.156). Co-variables did not affect the success and survival rates (p>0.05).

CONCLUSIONS

Metal-ceramic crowns showed a higher success rate than composite restorations. The survival rates were similar, but composite restorations presented a higher need for repairs.

CLINICAL SIGNIFICANCE

Post-retained composite restorations may need more reinterventions during the lifecycle, although more preservation of sound tooth structure is expected with a large restoration of resin post-and-core. These aspects have to be discussed with the patient for decision-making planning.

Success of Nonsurgical Endodontically Treated Posterior Teeth with Complex Restorative/Prosthodontic Treatments: A Retrospective Study

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 follow-up 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.

A Comparative Study of the Marginal Fit of Endocrowns Fabricated From Three Different Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) Ceramic Materials: An In Vitro Study

INTRODUCTION

The marginal seal and adaptation are important factors for successful restoration. An inadequate marginal seal can lead to bacterial microleakage, plaque accumulation, and eventually treatment failure This in vitro study aimed to compare the marginal gap of endocrowns fabricated from three different computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials.

METHODS

Thirty extracted mandibular molars were selected for the study. Endocrown preparations were completed after root canal treatment. Teeth were divided into three groups to receive endocrowns fabricated of lithium disilicate ceramic (IPS-e.max CAD, Ivoclar Vivadent AG, Schaan, Liechtenstein), zirconia-reinforced lithium silicate ceramic (VITA Suprinity®, VITA Zahnfabrik, Bad Säckingen, Germany), and polymer-infiltrated ceramic (VITA Enamic®, VITA Zahnfabrik). The digital impressions were transferred to the design software to construct the endocrowns. The endocrowns were milled and cemented. The marginal fit was examined using a digital camera stereomicroscope at a magnification of 80X. Images were transferred to Image-J software (National Institutes of Health, Bethesda, Maryland, United States) to measure the marginal gap.

RESULTS

One-way ANOVA showed a significant difference in the marginal gap between the different ceramic groups (P=0.006). Tukey's Honest Significant Difference (HSD) post-hoc test showed that VITA Suprinity had significantly higher gap width values than VITA Enamic (P=0.005). No significant differences in gap width values were found between VITA Enamic and IPS e.max CAD or between VITA Suprinity and IPS e.max CAD (P>0.05).

CONCLUSION

The marginal gap of endocrown restorations varies with different CAD/CAM materials (zirconia-reinforced lithium silicate glass-ceramic, polymer-infiltrated hybrid ceramic, and lithium disilicate glass-ceramic), but are all within clinically acceptable marginal gap width.

Effect of surface treatment, ferrule height, and luting agent type on pull-out bond strength of monolithic zirconia endocrowns

PURPOSE

To evaluate the effect of different surface treatments, ferrule heights, and luting agents on the pull-out bond strength (PBS) of computer-aided design/computer-aided manufacturing (CAD-CAM) monolithic endocrowns.

METHODS

After endodontic treatment and preparation for two endocrown designs (ferrule height 0 mm or 2 mm), CAD-CAM monolithic zirconia endocrowns were fabricated for 80 mandibular molars. Each endocrown design group was then divided on the basis of surface treatment into two groups: half were air-abraded and half were air-abraded/laser-irradiated. Then, all treated groups were further divided into two subgroups (n = 10) and cemented to teeth with either a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing resin luting agent (Panavia SA) or a combination of MDP-containing primer and MDP-free resin luting agent (Monobond Plus/Multilink Automix). PBS was measured with a universal test machine after simulated chewing and thermocycling. Three-way ANOVA and the post-hoc Bonferroni test were used for statistical analysis.

RESULTS

PBS was significantly associated with type of surface treatment, type of luting agent, and ferrule height. Air-abraded/laser-irradiated endocrowns with a 2-mm ferrule that were cemented with Monobond Plus/Multilink Automix had the highest PBS (P < 0.05).

CONCLUSION

Surface treatment with air abrasion/laser irradiation, presence of a ferrule, and priming with an MDP-containing primer increased the PBS of monolithic zirconia endocrowns.

An Umbrella Review of Systematic Reviews and Meta-Analyses Evaluating the Success Rate of Prosthetic Restorations on Endodontically Treated Teeth

Materials and Methods

The electronic search was conducted in the MEDLINE/PubMed, Cochrane, and Google Scholar databases until November 2020, regardless of language limitations. The inclusion criterion was as follows: S/M-R regarding prosthetic restorations in endodontically treated teeth. Three qualified researchers evaluated the inclusion criteria and bias risk. The fourth investigator was referred to when facing any doubtfulness.

Results

From 43 achieved S/M-R, 14 studies were selected for this inquiry. Primary extracted information included success rate, survival rate, and postendodontic failure rate. Five S/M-R had a moderate risk of bias, and nine S/M-R had a low risk of bias and were considered strong clinical evidence in this examination. According to the low-risk reports, the success rate of fiber posts was higher than that of metal posts; the rate of root fracture in metallic and fiber posts was alike; the failure rate for fiber posts was comparable to fixed partial dentures or single crowns; the construction of endocrowns was likely to perform better than intracanal posts, composite resin, or inlay/onlay restorations.

Conclusion

It appears that with practice and experience, deciding which type of restoration to choose changes. In dental restorations associated with root canal therapy, the single crowns are likely to be a proper option. Nevertheless, due to the heterogeneity of the studies, more clinical assessments are required to achieve more specific findings in this field.

Evaluation of titanium mesh and fibers in reinforcing endodontically treated molars: An in vitro study

Aim/Objective:

We aimed to evaluate the fracture resistance of titanium mesh and fibers that could aid as a substitute for crown coverage.

Materials and Methodology:

Forty extracted human mandibular molar teeth were selected for this study and were divided into four groups (n = 10). Access cavity preparation was done in all experimental teeth (Groups 2–4) maintaining 1.2–1.5 mm diameter of tooth structure around the circumference to mimic the structural loss of teeth due to the extent of dental caries. Group 1 consisted of intact teeth which were assigned as control. Group 2 was reinforced with titanium mesh. Group 3 was reinforced with glass fiber. Group 4 was reinforced with polyethylene fiber. The access cavities in all the experimental teeth were later filled with nanohybrid composite and were subjected to fracture resistance using a universal testing machine.

Results:

The results of the study were evaluated statistically using the Kruskal–Wallis test. There was no statistically significant difference among the experimental and control groups.

Conclusion:

Within the constraint of this in vitro study, an inference can be given that fiber-reinforced composite and titanium mesh could rule out the mandatory procedure of crown placement for endodontically treated molars.

Retrospective study of fracture survival in endodontically treated molars: the effect of single-unit crowns versus direct-resin composite restorations

Objectives

This study was conducted to compare the post-fracture survival rate of endodontically treated molar endodontically treated teeth (molar ETT) restored with resin composites or crowns and to identify potential risk factors, using a retrospective cohort design.

Materials and Methods

Dental records of molar ETT with crowns or composite restorations (recall period, 2015–2019) were collected based on inclusion and exclusion criteria. The incidence of unrestorable fractures was identified, and molar ETT were classified according to survival. Information on potential risk factors was collected. Survival rates and potential risk factors were analyzed using the Kaplan-Meier log-rank test and Cox regression model.

Results

The overall survival rate of molar ETT was 87% (mean recall period, 31.73 ± 17.56 months). The survival rates of molar ETT restored with composites and crowns were 81.6% and 92.7%, reflecting a significant difference (p < 0.05). However, ETT restored with composites showed a 100% survival rate if only 1 surface was lost, which was comparable to the survival rate of ETT with crowns. The survival rates of ETT with composites and crowns were significantly different (97.6% vs. 83.7%) in the short-term (12–24 months), but not in the long-term (> 24 months) (87.8% vs. 79.5%).

Conclusions

The survival rate from fracture was higher for molar ETT restored with crowns was higher than for ETT restored with composites, especially in the first 2 years after restoration. Molar ETT with limited tooth structure loss only on the occlusal surface could be successfully restored with composite restorations.

Conservative management of extensively damaged endodontically treated tooth using computer-aided design and computer-aided manufacturing-based hybrid-ceramic endocrown: A clinical report

Restoring extensively damaged endodontically treated posterior teeth is always a challenge in dentistry. The use of endocrowns has gained popularity in restoring severely damaged endodontically treated teeth (ETT) in recent years. In this clinical report, a structurally compromised mandibular second molar with symptomatic irreversible pulpitis and normal apical tissue was endodontically treated. Surgical crown lengthening was attempted thereafter to increase the crown height. However, marginal periodontal tissue re-growth occurred after surgical crown lengthening. The tooth was subsequently restored with endocrown which was fabricated using computer-aided design and computer-aided manufacturing-based hybrid-ceramic. In conclusion, endocrown can be a viable restorative modality for ETT with compromised clinical crown height.

Survival Rates of Unrestorable Fracture of Endodontically Treated Anterior Teeth Restored with Resin Composites or Crowns: A Retrospective Cohort Study

Introduction

Current guidelines for the restoration of endodontically treated anterior teeth (ETT) are based on laboratory results and insufficient clinical findings. This retrospective cohort study aimed to compare the survival rates of ETT with unrestorable fracture restored with direct resin composite (DRC) or full coverage crown (FCC), and identify predisposing factors.

Methods and Materials

Dental records and radiographs of ETT restored with DRC or FCC were collected from the dental charts of patients who received endodontic treatments and attended recall(s) from 2007 to 2019. Clinical/radiographic data and incidence of unrestorable fracture were recorded. Survival rates of ETT with unrestorable fracture treated with DRC and FCC were analyzed using Kaplan-Meier survival analysis and log-rank test, whereas predisposing factors were identified using Cox proportional-hazard model. Moreover, the survival rates of maxillary ETT with different sites of remaining cervical tooth structure were analyzed.

Results

A total of 263 ETT with 157 DRC and 106 FCC were recruited. At an average recall period of 38 months, the survival rate of ETT restored with FCC was significantly higher (99.1%) than DRC (90.4%) (P<0.05). The predisposing factors of ETT with FCC were not identified; however, the identified predisposing factors of ETT with DRC were: (i) considered less than three walls of remaining cervical tooth structure, (ii) the ratio between root dentin thickness and root canal width at the cervical region was less than 1:1:1, (iii) loss of posterior-teeth support, and (iv) parafunctional habits. Maxillary ETT with complete or palatal structure had a significantly higher survival rate than those without the palatal structure (P<0.05).

Conclusion

Based on the findings of the current cohort study, the survival rate of ETT with unrestorable fracture restored with FCC was significantly higher than DRC. However, ETT without predisposing factors were not susceptible to fracture and could be successfully restored with DRC.

Fracture strength of non-invasively reinforced MOD cavities on endodontically treated teeth

The purpose of this in-vitro study was to evaluate the fracture resistance and failure mode of non-invasively reinforced endodontically treated mandibular molars. Sixty freshly extracted defect-free mandibular molars were divided into four experimental groups with extensive MOD cavities on endodontically treated teeth with different restoration types and one control group with intact teeth (n  = 12). The groups were as follows: “Normal”: direct resin composite; “Ring”: glass fiber-reinforced strip (Dentapreg) wrapped around buccal and lingual walls followed by direct resin composite; “Inlay”: indirect CAD/CAM resin composite inlay; “Onlay”: indirect CAD/CAM resin composite onlay; “Intact”: Intact teeth (Control). Tetric EvoCeram and Adhese Universal (Ivoclar Vivadent) were used for direct restorations and Tetric CAD (Ivoclar Vivadent) adhesively luted with Adhese Universal and Variolink Esthetic LC (Ivoclar Vivadent) were used for indirect restorations. All teeth were submitted to thermo-mechanical cyclic loading. All samples were then submitted to a compressive load until fracture. Fracture load was noted and teeth were analyzed to classify the failure mode as either catastrophic (C) or non-catastrophic (NC). No statistically significant difference was found between fracture strength of the five groups when all specimens were considered (p = 0.1461). Intact group showed the lowest percentage of catastrophic failures (41.67%). Ring group presents less catastrophic failures (75%) than Normal group (83.34%), and failures of indirect restorations—Inlay and Onlay—were almost all catastrophic (91.67% and 100%, respectively).

Survival and success of endocrowns: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Endocrowns are a monoblock type of restoration that use the pulp chamber and remaining coronal tooth structure as a means of retention. However, data on their long-term survival and success rates as compared with conventional crowns are lacking.

PURPOSE

The purpose of this systematic review and meta-analysis was to collate published work on endocrowns to assist clinicians in making decisions on when and whether they are an appropriate restorative option with a predictable outcome for extensively damaged endodontically treated teeth.

MATERIAL AND METHODS

Databases such as PubMed (MEDLINE), Scopus, EMBASE, Cochrane library, and Google Scholar were searched up to June 2019 for clinical and in vitro studies on endocrown survival and success rates. For the meta-analysis, endocrown and conventional crown survival and success rates were compared, and the pooled effects were presented as relative risks and 95% confidence intervals using a random effects model.

RESULTS

Ten studies fulfilled the inclusion criteria (3 clinical and 7 in vitro) and were included in the systematic review. The meta-analysis of the clinical studies showed an estimated overall 5-year survival rate of 91.4% for endocrowns and 98.3% for conventional crowns. The estimated overall 5-year success rates were 77.7% for endocrowns and 94% for conventional crowns. There were no significant differences in overall survival or success estimates between the assessed restorations (P>.05).

CONCLUSIONS

Additional well-designed clinical studies with long-term assessment are needed; however, endocrowns appear to be a promising conservative restorative option with acceptable long-term survival for endodontically treated posterior teeth in selected patients.

An insight into patient's perceptions regarding root canal treatment: A questionnaire-based survey

Background:

A key setback of root canal treatment (RCT) is that most patients lack adequate knowledge about it. Understanding and identifying the factors that hinder or discourage patients from undergoing RCT is necessary to adequately address the issue. The review of literature shows that there is a paucity of data about the awareness and acceptance of RCT among patients in Indian population. Thus, the study was conducted with aim to assess patients’ awareness of RCT among patients reporting in Desh Bhagat Dental College and Hospital, Mandi Gobindgarh. By surveying the patients, a broad patient perspective on the issue was sought.

Materials and Methods:

This survey was conducted with the help of prestructured questionnaire consisting of 15 questions, distributed to random 450 patients coming to the outpatient department of Conservative dentistry and Endodontics in Desh Bhagat Dental College and Hospital. The completed questionnaires were then analyzed to assess patients’ experiences, concerns, and perceptions about RCT.

Results:

There is a lack of awareness among patients regarding RCT.

Conclusion:

It is important to create more awareness among the populace of our country about the significance of maintaining a healthy dentition and attendant sequel if not done so. More patients would consider having endodontic procedures if properly made aware of.

Fracture resistance, gap and void formation in root-filled mandibular molars restored with bulk-fill resin composites and glass-ionomer cement base

AIM

To evaluate fracture resistance and gap/void presence of root-filled mandibular molars restored with 2 bulk-fill and 1 conventional resin composites, with or without a glass-ionomer cement (GIC) base.

METHODS

Coronal access and mesio-occlusal (MO) cavities were prepared, then root canal treatment was performed on 30 mol/L. The teeth were randomly divided, according to the cavity volume, into 6 experimental groups (N = 5) and restored with conventional/light-cured (Ceram-X), bulk-fill/light-cured (SureFil SDR) or bulk-fill/dual-cured (Core-X Flow) with/without a 2-mm thick GIC base. Gaps and voids (%) were determined using microcomputed tomography. Intact teeth and unrestored teeth were used as negative and positive controls. Fracture load (N) was determined using a universal testing machine.

RESULTS

No significant difference in fracture resistance or gap/void formation was found among the 3 resin composites. GIC-base groups revealed significantly lower fracture strength than intact teeth, while fracture strengths of no GIC-base groups were not significantly different from intact teeth. GIC-base groups revealed significantly more gaps and voids in the area of the GIC than the resin composite.

CONCLUSION

Conventional and bulk-fill resin composites provided similar fracture resistance and gaps/voids in root-filled molars with MO cavities. Placing a GIC base decreased fracture resistance and increased gap/void formation.

Endodontically treated posterior teeth restored with or without crown restorations: A 5-year retrospective study of survival rates from fracture

AIM

The aim of the present study was to investigate survival rates from fracture of endodontically treated posterior teeth (ETT) restored with or without crowns with recall periods of up to 5 years.

METHODS

ETT with single-unit crown or resin composite restorations were studied based on the inclusion criteria. Restoration, tooth structure loss, adjacent teeth, fracture, and restorability were recorded. Survival rates from fracture were calculated, and risk factors were identified.

RESULTS

Overall, survival rate of ETT with crowns (92.2%) was significantly higher than resin composites (77.4%) (P < 0.05). ETT with one or two surface loss/es and two adjacent teeth had a high survival rate of 86.9%, which was not significantly different to ETT with crowns (P ≥ 0.05). Restoration and adjacent teeth were identified as significant factors. The majority of fractured ETT with resin composites were restorable, whereas those with crowns were unrestorable. Survival rates from unrestorable fracture were not significantly different between the crown (93.1%) and resin composite (96%) (P ≥ 0.05).

CONCLUSIONS

The survival rate from the fracture of ETT restored with crowns was significantly higher than ETT restored with resin composites, but was not significantly different to ETT with one or two ETT with one or two surface loss/es and two adjacent teeth. ETT restored with resin composites had mostly restorable fracture, whereas ETT with unrestorable fracture were similar between the two restorations.