Effect of bleaching agents and soft drink on titanium surface topography

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Histopathological Condition of the Remaining Tissues after Endodontic Infection of Rat Immature Teeth

Introduction: Recently, case reports have shown that immature teeth diagnosed with necrotic pulp and periapical periodontitis can be repaired through a regenerative endodontic procedure. True regeneration depends on the presence of stem cells in the remaining vital tissues. The aim of this study was to evaluate the histologic condition of the pulp tissue, root apical papilla, and periapical tissues after inducing endodontic infection in immature rat teeth for different periods. Methods: This study evaluated 18 first upper rat molars (36 roots). Periapical lesions were induced and were confirmed radiographically, and the animals were divided into 3 groups according to the days of pulp exposure for endodontic infection induction: 30, 60, and 90 days. Histologic analysis was performed in 5 different areas (ie, cervical, middle, and apical root canal thirds; the apical papilla; and the periapex surrounding the apical papilla). Results: At 30 days, one third of the specimens still showed vital but intensely inflamed pulp tissue in the apical third and vital apical papilla with varying degrees of inflammation. After 60 days, the results were similar with respect to the apical pulp tissue and apical papilla. Completely necrotic pulp tissue in the space canal and vital apical papilla were observed in about 67% of the cases after 90 days. Conclusions: Vital pulp tissue was observed in the apical third until 60 days and in the vital apical papilla until 90 days of infection in a rat model.

A Quality Assessment of Titanium Castings Produced in an Experimental Short-Heating-Cycle Investment

The aim of this study was to evaluate the quality of casting produced in an experimental short-term heating-cycle investment. Thus, reaction layer and castability of titanium casting using an experimental spinel-based investment (VR) with short heating cycle were compared with the commercial short-heating-cycle spinel-based investment Trinell (TR), the silica-phosphate-based investment Rematitan Plus ( RP), and the conventional spinel-based investment Rematitan Ultra (RU). VR has polymeric fibers added to inorganic particles. Reaction layer assessments were carried out using Vickers hardness and elemental analysis using dispersive X-ray microanalysis (EDX). Mesh patterns were used for castability test, and powder characterization was made by scanning electron microscopy (SEM). Hardness evaluation showed no difference among the investments between 100 and 200 mu m. The most important contaminant element for VR, TR, and RU was oxygen. Higher levels of mold filling were found for TR, VR, and RU compared with that obtained with RP. The quality of castings, characterized by means of the assessments of reaction layer and castability, made from the VR was similar to the commercial investments TR and RU but superior to the RP.

Adhesive bonding of resin composite to various titanium surfaces using diferente metal conditioners and a surface modification system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Streptococcus Mutans Adhesion to Titanium After Brushing with Fluoride and Fluoride-Free Toothpaste Simulating 10 Years of Use

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The impact of the addition of iodoform on the physicochemical properties of an epoxy-based endodontic sealer

Due to the low radiopacity of Sealer 26, iodoform is frequently empirically added to this sealer. Thus, the interference of this procedure with the physicochemical properties of Sealer 26 must be evaluated. Objective: This study evaluated the influence of the addition of iodoform on setting time, flow, solubility, pH, and calcium release of an epoxy-based sealer. Material and Methods: The control group was pure Sealer 26, and the experimental groups were Sealer 26 added with 1.1 g, 0.55 g or 0.275 g of iodoform. Setting time evaluation was performed in accordance with the ASTM C266-03 speciflcation. The analysis of flow and solubility was in accordance with the ISO 6876-2001 speciflcation. For the evaluation of pH and calcium ion release, polyethylene tubes were filled with the materials and immersed in flasks with 10 ml of deionized water. After 24 h, 7, 14, 21, 28, and 45 days pH was measured. In 45 days, the calcium released was evaluated with an atomic absorption spectrophotometer. Results: The addition of iodoform increased setting time in comparison with pure sealer (P < 0.05). As for flow, solubility, and calcium release, the mixtures presented results similar to pure sealer (p > 0.05). In the 24 h period, the mixture with 1.1 g and 0.55 g of iodoform showed lower pH than pure sealer and than sealer added with 0.275 g of iodoform (P < 0.05). Conclusions: The iodoform added to Sealer 26 interferes with its setting time and solubility properties. Further studies are needed to address the clinical signiflcance of this interference.

Healing of normal and osteopenic bone with titanium implant and low-level laser therapy (GaAlAs): a histomorphometric study in rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Signaling Pathways Activation by Primary Endodontic Infectious Contents and Production of Inflammatory Mediators

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mechanical and chemical analyses across dental porcelain fused to CP titanium or Ti6Al4V

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

CT study of the performance of reciprocating and oscillatory motions in flattened root canal areas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Changes in heart period during endodontic treatment

Background: Tooh extraction was demonstrated to increase sympathetic modulation of the heart, however, it is not understood the effects of endodontic treatment on cardiac autonomic regulation. We evaluated heart rate variability (HRV) during endodontic treatment. Method: 50 male and female patients aged between 18 and 40 years old and diagnosed with irreversible pulpitis or pulp necrosis of the lower molars with indication of gender endodontic treatment were analyzed. HRV was analyzed in the time (SDNN, RMSSD, pNN50) and frequency (LF, HF and LF/HF ratio) domains recorded in the first session of root canal treatment. The indices were analyzed in the following periods: T1) ten minutes before the endodontic treatment, T2) ten minutes after the administration of anesthesia before endodontic treatment, T3) during the entire period of endodontic treatment and T4) thirty minutes after the end of the endodontic treatment. Results: The SDNN, RMSSD and pNN50 indices increased at T2 compared to T1, the pNN50 and RMSSD indices increased at T3 and T4 compared to T2. The LF in normalized units increased at T4 compared to T2 and in absolute units it was increased at T4 compared to T1. The HF in normalized units was reduced at T4 compared to T2 and in absolute units was reduced at T1, T3 and T4 compared to T2. The LF/HF ratio was higher at T4 compared to T2. Conclusion: The global modulation of heart increases after local anesthesia and vagal tone reduce during surgery procedures and after the surgical procedures.

Clinical investigation of bacterial species and endotoxin in endodontic infection and evaluation of root canal content activity against macrophages by cytokine production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

18-Year Follow-up of Dens Invaginatus: Retrograde Endodontic Treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A MICROSTRAIN COMPARISON OF PASSIVELY FITTING SCREW-RETAINED AND CEMENTED TITANIUM FRAMEWORKS

Statement of problem. An imprecise fit between frameworks and supporting dental implants in loaded protocols increases the strain transferred to the periimplant bone, which may impair healing or generate microgaps.Purpose. The purpose of this study was to investigate the microstrain between premachined 1-piece screw-retained frameworks (group STF) and screw-retained frameworks fabricated by cementing titanium cylinders to the prefabricated framework (group CTF). This procedure was developed to correct the misfit between frameworks and loaded implants.Material and methods. Four internal hexagon cylindrical implants were placed 10 mm apart in a polyurethane block by using the surgical guides of the corresponding implant system. Previously fabricated titanium frameworks (n=10) were divided into 2 groups. In group STF, prefabricated machined frameworks were used (n=5), and, in group CTF, the frameworks were fabricated by using a passive fit procedure, which was developed to correct the misfit between the cast titanium frameworks and supporting dental implants (n=5). Both groups were screw-retained under torque control (10 Ncm). Six strain gauges were placed on the upper surface of the polyurethane block, and 3 strain measurements were recorded for each framework. Data were analyzed with the Student t test (alpha=.05).Results. The mean microstrain values between the framework and the implants were significantly higher for group STF (2517 me) than for group CTF (844 me) (P<.05).Conclusions. Complete-arch implant frameworks designed for load application and fabricated by using the passive fit procedure decreased the strain between the frameworks and implants more than 1 piece prefabricated machined frameworks.