Systematic review fracture resistance of endodontically treated posterior teeth restored with fiber reinforced composites- a systematic review.

BACKGROUND: Large cavity designs and access cavities impair endodontically treated tooth fracture resistance. As the tooth's strength is known to reduce significantly after the root canal treatment, occlusal loading as a result of functions such as chewing, biting and certain parafunctional tendencies makes the endodontically treated tooth vulnerable to fracture. Hence, after endodontic treatment, it is vital to give adequate and appropriate restorative material to avoid tooth fractures. Accordingly, the choice of such restorative material should be dictated by the property of fracture resistance. OBJECTIVE: The goal of this study was to conduct a systematic review and critical analysis of available data from in vitro studies examining the fracture resistance of endodontically treated posterior teeth restored with fiber-reinforced composites. METHODOLOGY: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRIS-MA) Statement was used to guide the reporting of this systematic review A comprehensive literature search was performed using MEDLINE (via PubMed), Scopus, ScienceDirect, Google Scholar, and LILACS. A manual search of the reference lists of the articles was also performed. The databases provided a total of 796 studies from the electronic systematic search. The databases provided a total of 796 studies from the electronic systematic search. Two reviewers scrutinized the papers for eligibility based on inclusion/exclusion criteria and extracted data. The studies were assessed for their potential risk of bias. Based on modified JBI & CRIS (checklist for reporting in vitro studies) guidelines, along with the methodology and treatment objective, we have formulated 13 parameters specifically to assess the risk of bias. A total of 18 studies met the inclusion criteria and were included for qualitative analysis. Considering the high heterogeneity of the studies included, a meta-analysis could not be performed. RESULTS: The majority of the included studies had a moderate or high risk of bias. When compared to traditional hybrid composites, fiber-reinforced composites showed increased fracture resistance of endodontically treated teeth in the majority of investigations. On the other hand, limited evidence was found for the bulk fill composites. Moreover, moderate evidence was found for the fracture resistance of inlays and fiber posts with fiber-reinforced composites for core build-up in endodontically treated teeth. No evidence could be found comparing the fracture resistance of endo crowns and fiber-reinforced composites in endodontically treated teeth. CONCLUSION: According to the research, using fiber-reinforced composites instead of conventional hybrid composites improves the fracture resistance of endodontically treated teeth. However, there was a high risk of bias in the research considered. No judgments could be reached about the superiority of one material over another based-on comparisons between other core restorations.

Comparative Clinical Evaluation of Composite Overcast Gold Post and Core Buildups in Endodontically Treated Teeth.

BACKGROUND: The management of non-vital teeth includes endodontic treatment and restoration followed by post and core restoration in selected cases. The present study was conducted to compare the indirect cast post, and core buildup with direct composite post build up in patients. MATERIALS AND METHODS: The present study was conducted on 128 teeth of 82 patients. The success rate over 3 years was evaluated clinically and radiographically by observing caries, tooth mobility, probing depth, periapical pathology, and root fractures. RESULTS: Group I consisted of 16 incisors, 20 canines, 22 premolars, and six molars while group II had 17 incisors, 14 canines, 25 premolars, and eight molars. The difference was statistical non-significant (p-0.1). Forty-four teeth in group I and 42 teeth in group II utilized composite cement, whereas 18 teeth in group I and 16 teeth in group II used GIC and zinc phosphate was used in two teeth in group I and six teeth in group II. The difference was statistical ly significant (p< 0.05). Four teeth in group I and 8 in group II were lost. One tooth in group I and two teeth in group II showed root fracture and three teeth in group I and six teeth in group II showed periapical pathology. The difference was statistically significant (p-0.01). Most common type of complication was probing depth > 4 mm, caries, tooth mobility, and root fracture. The difference was non- significant (p-0.31). CONCLUSION: Both composite post buildup and cast gold post and core build-up exhibited similar properties. CLINICAL SIGNIFICANCE: Both composite post buildup and cast gold post and core build-up exhibited similar properties hence either of the methods can be used in post core build up.

Evaluation of Fracture Resistance of Endodontically Treated Teeth Filled with Gutta-Percha and Resilon Obturating Material: An In Vitro Study.

BACKGROUND: As per many studies endodontically treated teeth are widely considered to be more susceptible to fracture than vital teeth. Obturation strains and post placement have been a major cause of vertical root fracture. Present study was conducted to compare in vitro fracture resistance after filling with either Gutta-percha or Resilon by lateral condensation techniques in root canals. This study evaluated a new thermoplastic synthetic polymer based on polyester, which contains bioactive and radiopaque filler, Resilon performs every way as Gutta-percha except that it allows the bonding agent to attach to the resin core and the dentin wall thus forming a monoblock. MATERIALS AND METHODS: In the present study 90 freshly extracted single-rooted human mandibular premolar teeth endodontically treated, were cut at the cemento-enamel junction, and were randomly divided into three groups of 30 each as teeth of Group A (Control) received no obturation, Group B teeth were obturated using Gutta-percha/AH26, and Group C teeth were obturated using Resilon/Epiphany obturating kit. Each specimen were mounted in acrylic in a polyvinyl ring and then tested for fracture resistance with the help of an universal testing machine. A compressive force was applied until the root is fractured. The data were subjected to analysis of variance for comparing mean difference of fracture resistance among three groups. Multiple comparisons among these groups were carried out by non-parametric Kruskal-Wallis analysis. A p value of <0.0001 was considered a statistically significant difference. RESULTS: The results obtain after analysis showed no significant differences in the fracture resistance between the two tested groups of endodontic sealers. CONCLUSION: Within the limitation of the present in-vitro study, Resilon/Epiphany sealer performs better than Gutta-percha/AH 26 sealer with lateral condensation technique.

Effect of saliva contamination on the shear bond strength of a new self-etch adhesive system to dentin.

AIMS AND OBJECTIVES: To evaluate the effect of saliva contamination on the shear bond strength of a new two-step self-etch adhesive (P90 system adhesive) to dentin and to determine the effect of contaminant removing treatments on the recovery of bond strengths. MATERIALS AND METHODS: The buccal surfaces of 40 human premolars were ground to expose dentin. The specimens were randomly divided into four groups. Group 1 is uncontaminated and serves as the control group. Further groups were divided based on the step in the bonding sequence when the contamination had occurred as follows: Group 2 (primer, saliva contamination, rinse and dry), group 3 (after procedure of group 2, reapplication of primer), and group 4 (after procedure like in control group, saliva contamination, rinse and dry). Filtek P90 composite resin cylinders of 3 mm diameter and 3 mm length were fabricated on the surfaces. Shear bond strength testing was done in an Instron Universal Testing Machine and the data were subjected to one-way analysis of variance (ANOVA) and Student's t-test. RESULTS: With P90 system adhesive, group 2 and group 4 showed lower shear bond strength than group 1 (control) and group 3 (P < 0.05). CONCLUSION: Saliva contamination significantly decreased the shear bond strength of the adhesive to dentin.

Stress distribution among periodontally compromised abutments: A comparative study using three-dimensional finite element analysis.

AIMS: The aim of the study was to evaluate the stress distribution patterns in teeth and supporting structures of fixed prosthesis and design modifications in a fixed prosthesis with either normal or reduced bone support of an additional abutment. Study was also undertaken to disprove Ante's law. MATERIALS AND METHODS: Main models and variations of main models (modification 1, 2, 3, 4, 5, 6, 7, 8) were subjected to 200 N at angulations of 90° and 15° on functional cusps. Results for each loading were obtained as stress distribution color images and numerical values were recorded. A three-dimensional finite element analysis study of variations of normal models was performed using two finite element softwares, namely PRO-Engineer wildfire version 1.0 manufacturer: Parametric technology corporation, Needham, MA 02494 U.S.A. RESULTS: When periodontal compromised abutment teeth was splinted with an additional abutment an increase of stress was observed in periodontally compromised abutments so an additional abutment is not required. Eventhough the pericemental area of compromised abutments with an additional abutment (canine) was more than the combined pericemental area of pontics to be replaced, stress generated was more on abutments. This disproves Ante's law. Hence, it may be a reference, but should not be the ultimate criterion in determining the number of multiple abutments. CONCLUSIONS: When periodontal compromised abutment teeth was splinted with an additional abutment an increase of stress was observed in periodontally compromised abutments so an additional abutment is not required. Even though the pericemental area of compromised abutments with an additional abutment (canine) was more than combined pericemental area of pontics to be replaced, stress generated was more on abutments. This disproves Ante's law. Hence, it may be a reference, but should not be the ultimate criterion in determining the number of multiple abutments.