Influence of increased patient age on longitudinal outcomes of root canal treatment: a systematic review.

OBJECTIVES: To conduct a systematic review of longitudinal endodontic outcomes in elders. BACKGROUND: Negative opinions about the prognosis of non-surgical root canal treatment (NSRCT) in elders affect decisions made by patients and dentists. Patient, caregiver and dentist attitudes and behaviours may interact to decrease the provision of NSRCT. Critical examination of the available evidence through systematic review could provide objective data to assist patients, caregivers, healthcare providers and third-party payers in making decisions about the efficacy of NSRCT in elders and provide a robust foundation for the health promotion of NSRCT in elders. METHODS: Inclusion/exclusion criteria were used for defined searches in MEDLINE and Cochrane CENTRAL. Title lists were scanned, and abstracts read to determine utility; articles meeting inclusion/exclusion criteria were analysed. Data were extracted and compiled into a table of evidence. RESULTS: Defined searching produced 3605 titles; 24 articles were included, nine prospective and 15 retrospective. Overall study quality was good. Patient samples mostly represented modern populations from countries with very high human development indices. Over 17 430 teeth were included. Meta-analysis was not attempted due to heterogeneity in reporting. All 24 included papers demonstrated that increased patient age did not decrease the success or survival rates of NSRCT. CONCLUSIONS: This systematic review of longitudinal NSRCT outcomes demonstrated that increased patient age did not decrease the success of NSRCT. Patient age is not a prognostic factor for NSRCT. Age should not be considered by dentists or patients when making NSRCT decisions.

Prevalence of root canal treatment and periapical radiolucency in elders: a systematic review.

INTRODUCTION: Neither the prevalence of periapical radiolucency (PARL), a surrogate for disease, nor the prevalence of non-surgical root canal treatment (NSRCT) in elders have been subjected to systematic review. The purpose of this study was to conduct systematic review and meta-analysis of the prevalence of PARL and NSRCT in elders. METHODS: Inclusion/exclusion criteria were used for defined searches in MEDLINE and Cochrane CENTRAL. Title lists were scanned and abstracts read to determine utility; articles meeting the criteria were analyzed. Weighted mean percentages were calculated for prevalence of PARL, NSRCT, and PARL in both teeth with and without NSRCT. RESULTS: Defined searching produced 3576 titles; 29 prevalence articles were included. Patient samples mostly represented modern populations from countries with very high human development indices. Meta-analyses were performed on up to 74 000 elders' teeth. For those aged 65+, the prevalence of all teeth with NSRCT was extremely high, 21%; the prevalence of all teeth with PARL was quite high, 7%; the prevalence of PARL in NSRCT teeth was high, 25%; and the prevalence of PARL in untreated teeth was surprisingly high, 4%. In elders, the prevalence of NSRCT and PARL separately increased with age; whereas, PARL in NSRCT teeth decreased with age. CONCLUSIONS: In comparison to general adult populations, elders had: a much higher prevalence of NSRCT, a higher prevalence of PARL, a lower prevalence of PARL in NSRCT teeth, and a higher prevalence of PARL in untreated teeth. Teeth saved through NSRCT were preferentially retained by elders.

Histopathological evaluation of the effects of variable extraoral dry times and enamel matrix proteins (enamel matrix derivatives) application on replanted dogs' teeth.

The extra-alveolar dry period and storage medium in which the tooth was kept prior to replantation remain the critical factors affecting the survival and regeneration of the damaged periodontium. When the replantation is delayed, replacement root resorption is the most common complication following replantation of an avulsed tooth. The aim of this histological study was to evaluate the periodontal healing of replanted dogs' teeth after 20 min (short) and 60 min (long) extraoral dry time with and without the application of enamel matrix proteins. Eighty mature premolar roots (40 teeth) maxillary and mandibular premolars were extracted, the root canals were accessed, instrumented, and filled using a lateral condensation technique, and the access cavity was restored with amalgam. Each root was randomly assigned to one of experimental groups: Groups I and II: Roots were replanted after an extraoral dry time of 20 min. In group II, Emdogain(®) (Biora, Malmo, Sweden) was applied directly to the external root surface with complete coverage. Groups III and IV: Roots were replanted after an extraoral dry time of 60 min. In group IV, Emdogain(®) was applied to the whole external root surface before replantation. Roots that replanted within a total extraoral dry time of 10 min were used as negative controls, while those replanted after 90 min of extraoral dry time were assigned as positive controls. After 4 months, the dogs were euthanized, and the maxillary and mandibular processes were processed for histology and microscopically evaluated. Statistical analysis showed no significant differences (P = 0.1075) among the experimental groups. The results of this study show that 20 min of extraoral dry time is as detrimental to the PDL cells as 60 or 90 min of extraoral dry time, with avulsed dogs' teeth, even when replanted with an inductive material such as EMD. This study provides strong evidence in relation to the threshold of the extraoral dry time of avulsed teeth, suggesting that the extraoral dry time threshold of PDL cell viability is significantly less than that which current guidelines promote.

Intraoperative endodontic applications of cone-beam computed tomography.

INTRODUCTION: The use of cone-beam computed tomography (CBCT) in endodontics for diagnosis, treatment planning, and follow-up has been extensively reported in the literature. Compared with the traditional spiral computed tomography, high-resolution limited CBCT results in a fraction of the effective absorbed dose of radiation. However, it should be prescribed only after weighing the cost of radiation exposure with the benefit of the diagnostic information that can be obtained from the scan. METHODS: The purpose of this article is to discuss the application and advantages of intraoperative CBCT in endodontics, while reducing radiation exposure during complex endodontic procedures. RESULTS: In cases of increased difficulty or intraoperative complications such as complex anatomy, dystrophic calcifications, root resorptions, perforations, and root fractures, it is prudent to consider the use of CBCT with its inherent diagnostic value and limited radiation exposure. CONCLUSIONS: The benefits of the added diagnostic information provided by intraoperative CBCT images in select cases justify the risk associated with the limited level of radiation exposure.

Evaluation of the colour change in enamel and dentine promoted by the interaction between 2% chlorhexidine and auxiliary chemical solutions.

To evaluate the colour change in enamel and dentine, promoted by interaction of 2% chlorhexidine gluconate (CHX) with 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Fragments containing enamel and dentine were obtained from the crowns of extracted bovine incisors. Before and after immersion of the samples in the substances, they were evaluated with reference to the colour of the enamel and dentine. The values obtained in numerical scores were subjected to statistical analysis using Wilcoxon test. A colour change in the enamel and dentine in groups treated with CHX gel + NaOCl and CHX gel + NaOCl + EDTA, and a change in colour only in the dentine in groups treated with CHX solution + NaOCl and CHX solution + NaOCl + EDTA. When used prior to NaOCl, CHX has the ability to induce a colour change in dental structures.

Bond strength of Resilon/Epiphany compared with Gutta-percha and sealers Sealer 26 and Endo Fill.

This study evaluated the bond strength of Epiphany(®)/Resilon(®) to radicular dentine and compared this with that of Gutta-percha sealed with Sealer 26 and also Endo Fill(®). Fifteen human single-rooted extracted teeth had their root canals enlarged to a standardised internal root diameter of 1.5 mm. The teeth were filled with: Group I--Epiphany(®)/Resilon(®) cones, Group II--Sealer 26(®)/Gutta-percha cones and Group III--Endo Fill(®)/Gutta-percha cones. Three 2 mm-thick cross-sections were obtained from each tooth (n = 15) and subjected to a push-out test (1 mm min(-1)). The means (MPa) were compared using anova /Newman-Keuls tests. There were no statistically significant differences between Group I and Group II (P > 0.01). Both bond strengths were significantly higher than that of Group III (P < 0.01). The root canal filling system Epiphany(®)/Resilon(®) showed bond strength similar to that of Sealer 26(®)/Gutta-percha. Both were higher than that of Endo Fill(®)/Gutta-percha.

Resinous denture base fracture resistance: effects of thickness and teeth.

PURPOSE: Fracture is a frequent complication of resinous prostheses. The purpose of this study was to evaluate the effect of thickness on flexural strength of a resinous prosthesis containing a prosthetic tooth. MATERIALS AND METHODS: Beam-shaped specimens 65-mm long, 12-mm wide, and 1, 2, 3, 4, or 6 mm in thickness were made from high-impact strength polymethyl methacrylate denture base material, each containing a resin-based molar prosthetic tooth at the center of the beam. A group of 3-mm-thick specimens without a prosthetic tooth (n = 7) were also made. Specimens were aged artificially, loaded in three-point flexure, examined fractographically, and analyzed. RESULTS: The 1- and 2-mm-thick beams underwent considerable deformation at low loads. Maximum loads varied considerably from 0.6 kg (1-mm beams) to 38 kg (6-mm beams). The 3-, 4-, and 6-mm beam groups all underwent brittle fracture, with mean relative flexural strengths of approximately 73 MPa. Denture teeth reduced the relative flexural strength of resin beams by 0.7 x. Fracture initiation sites were generally at tiny surface defects, but did not directly involve denture teeth. Denture resin fracture toughness was 3.2 MPa m1/2, and modulus of rupture was 104 MPa. CONCLUSION: Denture teeth substantially decreased the strength of resinous beams. Increased thickness markedly increased the load-bearing capacity of resinous beams containing denture teeth. Beams less than 2 mm in thickness with denture teeth were weakened substantially more than comparable beams of 2 mm or more in thickness. Surface finish was of critical importance. Fracture toughness was calculated fractographically, facilitating future forensic examination of clinically failed resinous prostheses.

Influence of endodontic irrigants on bond strength of a self-etching adhesive.

The aim of this in vitro study was to evaluate the bond strength of a self-etching adhesive system to dentine irrigated with sodium hypochlorite (NaOCl), chlorhexidine solution (CX) and ethylene diamine tetra acetic acid (EDTA) by microtensile testing. Sixty human third molars were sectioned 3 mm below the occlusal level and then randomly divided into six groups: G1(control), without irrigant solution; G2, 1% NaOCl; G3, 1% NaOCl followed by the application of 17% EDTA; G4, 2% CX; G5, 2% CX followed by the application of 17% EDTA and G6, 17% EDTA. The specimens received the self-etching adhesive system were restored with composite resin, then sectioned and trimmed to obtain four hourglass-shaped slabs from each tooth. The specimens were submitted to the microtensile test in a Universal Testing Machine at a crosshead speed of 0.5 mm min(-1) until fracture. The results were submitted to statistical analysis by anova /Newman-Keuls. The means and standard deviations (MPa) were: G1, 26.88 (±3.81); G2, 19.08 (±3.89); G3, 18.16 (±2.21); G4, 18.14 (±4.32); G5, 34.30 (±3.32); G6, 13.61 (±1.21). It was concluded that the application of 2% CX followed by the application of 17% EDTA resulted in increasing the bond strength of the self-etching adhesive system to dentine, when compared with the results obtained for the other tested groups.

In vitro antibacterial efficacy of endodontic irrigants against Enterococcus faecalis.

OBJECTIVE: The objective of this study was to compare the in vitro antimicrobial activity of 2% chlorhexidine gel against Enterococcus faecalis with sodium hypochlorite in 2 different concentrations (1.5% and 5.25%). STUDY DESIGN: Eighty human lower premolars with single root canals were prepared, autoclaved, and infected for 7 days with E. faecalis monocultures. The roots were then separated into 5 experimental groups according to the irrigant solution used during the standardized preparation. To assess the antimicrobial action of the irrigant solutions, 3 microbial samples were taken: S1--initial (before the biomechanical preparation), S2--posttreatment (immediately after the biomechanical preparation), and S3--final (7 days after the biomechanical preparation). The microbiological samples were plated to count the colony-forming units (CFU). RESULTS: The 2% chlorhexidine gel and 5.25% sodium hypochlorite significantly reduced the E. faecalis CFU in the posttreatment and final microbiological samples. The 1.5% sodium hypochlorite also reduced the E. faecalis CFU immediately after the root canal instrumentation, but the E. faecalis CFU increased in the final sample showing no statistical difference from the control group. CONCLUSION: The 2% chlorhexidine gluconate gel and 5.25% sodium hypochlorite were effective in eliminating E. faecalis even 7 days after the instrumentation; moreover, the higher the concentration of sodium hypochlorite the better its antimicrobial action.