Frank Ferreira Silveira

Comparative Analysis of Accessory Mesial Canal Identification in Mandibular First Molars by Using Four Different Diagnostic Methods

INTRODUCTION The objective of the present in vitro study was to compare 4 diagnostic methods to identify accessory mesial canals (AMCs) in lower first molars. METHODS Forty-four lower first molars were selected for assessment with cone-beam computed tomography (CBCT), digital radiography (DR), clinical inspection (CI), and dental operating microscope (DOM). Initially, axial images were obtained by using CBCT, and radiographs were taken in ortho, mesial, and distal angulations. The images were assessed by 2 independent groups of examiners, and all of the results obtained remained undisclosed until the end of the experiment. Subsequently, root canal access was prepared, and the mesial subpulpal groove was located by using sharp endodontic explorers. The roots were examined with DOM, and all identified canals were negotiated and instrumented by using a ProTaper Rotary System. The results were tabulated and statistically analyzed by nonparametric McNemar tests. RESULTS Twelve AMCs (27.0%) were identified by CBCT, and 58.0% were instrumented. No AMCs were visualized in any DR examined. Fifteen potential AMCs (34%) were identified by CI, but only 47.0% were confirmed after instrumentation. Thirteen AMCs (30.0%) were identified by DOM, and 84.0% could be negotiated and instrumented. CONCLUSIONS There were statistically significant differences between the 4 types of assessments for AMC identification. There was good agreement between DOM and CBCT, whereas DR and CI were not as precise as either of the other 2 diagnostic methods.

Calcium hydroxide induced apexification with apical root development: a clinical case report

AIM To report the induction of apical root development by calcium hydroxide in teeth with pulp necrosis and periapical radiolucency. SUMMARY A 10-year-old male patient was admitted to the clinic complaining of an intense pain and oedema on the anterior facial region, compatible with an acute dentoalveolar abscess. There was a previous history of dental trauma; only tooth 11 was negative to pulp sensitivity tests. Radiographically, tooth 11 exhibited incomplete root formation, characterized by a wide root canal, thin and fragile dentinal walls, and an extensive, divergent foraminal opening associated with an apical radiolucency. The first appointment focused on urgent local and systemic treatment. Apexification treatment commenced at the second session after 7 days, by means of chemo-mechanical debridement throughout the entire root canal, using K-files and irrigation with a 2.5% sodium hypochlorite solution. Subsequently, a calcium hydroxide paste was applied and changed four times over 8 months, when radiographic examination revealed complete closure of the foraminal opening, resulting in resolution of the periapical radiolucency and associated with 5 mm of additional root development. The root canal was filled by thermomechanical compaction of gutta-percha and sealer. A 3-year follow-up revealed normal periapical tissues and the absence of symptoms. KEY LEARNING POINTS * In young patients, dental trauma may cause pulp necrosis and arrest of root formation. * Under certain circumstances, chemo-mechanical debridement, including the use of a calcium hydroxide paste, is a valid alternative to mineral trioxide aggregate and or surgery for root-end closure. * In teeth with incompletely formed roots associated with periapical lesions, calcium hydroxide can induce periapical repair through the closure of the foramen and apical root development.

TGF-β1 and BMP-4 carried by liposomes enhance the healing process in alveolar bone

OBJECTIVE In this work we evaluated the bone-forming potential of BMP4, TGFβ1 and BMP4/TGFβ1 mixed by performing histological and morphometric analysis. We also evaluated the immunolabelling of fibronectin (FN) and collagen type III (Col III), two determinant proteins for the early phase of bone repair. DESIGN Histological, histomorphometric and immunohistochemistry analysis were used to evaluate new bone and blood vessels formation as well as fibronectin and collagen type III expression. 112 male Wistar rats weighing 250-300g had their maxillary second molar extracted. Sockets filled with blood clot (BC) or treated with L (empty liposome), P (PBS), BP (BMP-4 in PBS) and TP (TGF-β1 in PBS), as well as with BL (BMP-4 in liposome) and TL (TGF-β1 in liposome) administered isolated or in association (BTL) were obtained. The animals were sacrificed at 3, 7, 14 and 21 days after surgery. RESULTS An increased percentage of bone trabeculae, and a higher number of blood vessels were observed in groups BL or TL administered isolated or in association when compared to groups BC, L, P, BP and TP. Fibronectin and collagen type III analysis revealed enhanced expression firstly detected at 3 days followed by a peak at 7 days. Lower levels of immunoreactivity were observed in the sockets filled with blood clot, and treated with L, P, BP and TP when compared with sockets from groups BL, TL and BTL. CONCLUSION The present study indicates growth factors carried by liposomes, either in isolated or associated forms, as successful enhancers of the healing process in rat tooth sockets. We also conclude that the expression of fibronectin and collagen type III increases during the early phases of bone repair.

Periapical Repair in Dog Teeth: Root Canal Adhesive Filling by Using the Resilon System

INTRODUCTION New filling biomaterials with better physicochemical properties would create a favorable biologic environment for the healing of periapical tissues. The aim of this study was to evaluate periapical repair after biomechanical preparation and root filling with an adhesive system compared with the gold standard material (gutta-percha+sealer) in dog teeth. METHODS The pulp of 25 root canals was removed. The apical cementum layer was perforated, and the root canals were prepared up to size #60 K-file followed by step-back shaping with the #90 K-file and filled by the lateral condensation technique. In the experimental group (n=15), the Resilon System (Pentron Clinical Technologies, Wallingford, CT) was used. As a control material (n=10), gutta-percha cones and pulp canal sealer were used. After 60 days, the animals were killed, and 10 histologic parameters were evaluated. Differences among the groups were analyzed by using the Mann-Whitney and Fisher exact tests. RESULTS In radiographic and histologic evaluations, most fillings were slightly short of the apex. Progressive regenerative stages were observed; however, there was a reduced prevalence of biologic foraminal closure. No significant differences were observed between the 2 biomaterials with regard to any of the parameters evaluated (P>.05). CONCLUSIONS The Resilon System shows periapical biocompatibility equivalent to the gold standard material.

Effect of PDGF-BB, IGF-I Growth Factors and their Combination Carried by Liposomes in Tooth Socket Healing

This work evaluated the bone-forming potential of the platelet-derived growth factor isoform BB (PDGF-BB), insulin-like growth factor I (IGF-I), and mixed PDGF-BB/IGF-I delivered in liposomes compared with phosphate buffered saline (PBS), in the healing process of rat tooth sockets. One hundred and twelve Wistar rats were randomized into 7 groups of 16 animals each and were evaluated at 3, 7, 14 and 21 days after extraction of the maxillary second molars. The left sockets were treated with PBS (P), empty liposome (L), IGF-I in PBS (IP), IGF-I in liposome (IL), PDGF-BB in PBS (PDP), PDGF-BB in liposome (PDL) and both growth factors (GFs) together within liposomes (PDIL). The right sockets were filled with blood clot (BC). Histological and histomorphometric analyses were used to evaluate the formation of new bone and blood vessels. Immunohistochemistry was performed to evaluate the expression of osteocalcin and vascular endothelial growth factor (VEGF) during bone repair. Data were tested statistically using a Tukeys test according to a Dunns analysis and Mann-Whitney U test followed by Kruskal-Wallis one-way analysis. Results were considered significant when p<0.05. A significantly higher percentage of bone trabeculae and a higher number of blood vessels were observed in the IL, PDL and PDIL groups (p<0.05). However, these GF-liposome groups had statistically similar results. Immunohistochemical assays first detected osteocalcin and VEGF expression at 3 days followed by a peak at 7 days. Lower immunoreactivity levels were observed in the BC, L, P, IP and PDP groups compared with the IL, PDL and PDIL groups (p<0.05). The results suggest that GFs carried by liposomes, either in isolated or mixed forms, enhanced the healing process in rat tooth sockets. The differential expression of the osteogenic markers VEGF and osteocalcin in the early phases of bone healing support these findings.

Endodontic re-treatment associated with the elimination of amalgam root-end filling through sinus tracts: A report of two cases

Two patients presented with complaints of recurrent drainage of purulent exudate from sinus tracts, inflammation and pain after endodontic re-treatment of the maxillary left (Case 1) and right (Case 2) lateral incisors. The periapical lesions persisted after apical curettage, apicectomy and root-end filling with silver amalgam. Radiographic examination exposed the poor quality of the endodontic treatments and the silver amalgam root-end fillings, which were associated with periapical radiolucent areas in both teeth. The sinus tract persisted after root canal cleaning and shaping, followed by a calcium hydroxide root canal dressing. The root-end fillings were periapically dislodged with endodontic K-files, and showed progressive displacement by sinus tracts up to elimination in the oral cavity. Follow ups of 42 and 65 months post procedure revealed clinical disappearance of the symptoms, sinus tracts and exudates, and radiographs revealed that the repair process of the periapical radiolucent areas was quite advanced.

Filling Effectiveness and Dentinal Penetration of Endodontic Sealers: A Stereo and Confocal Laser Scanning Microscopy Study

The aim of this study was to evaluate the filling effectiveness and dentinal penetration of the sealers AH Plus, Pulp Canal Sealer EWT, Sealapex and MTA Fillapex applied according to the vertical condensation technique using thermoplastic gutta-percha. Forty single-rooted teeth were selected. After chemical-mechanical preparation and root-canal filling, sections of the root (2, 4 and 6 mm from the apex) were obtained and analyzed by stereo microscopy and confocal laser scanning microscopy. Data were tabulated and statistically analyzed. With regard to the assessment of void spaces in the filling material at 2 mm from the apex, the sealers showed similar results, but at 4 and 6 mm from the apex, MTA Fillapex had inferior performance compared to AH Plus (at 4 mm), Pulp Canal Sealer EWT (at 4 and 6 mm) and Sealapex (at 6 mm) (p<0.05). With regard to the penetration into dentinal tubules at 2 mm from the apex, the sealers also showed similar results, but at 4 and 6 mm Pulp Canal Sealer EWT had an inferior performance compared to MTA Fillapex and AH Plus, respectively (p<0.05). All four sealers were found to be similar regarding adaptation of the filling material to the root canal walls, except the MTA Fillapex, which showed failures at 4 and 6 mm from the root apex. With regard to the ability to penetrate into the dentinal tubules, the sealers were found to be equivalent, except for the Pulp Canal Sealer EWT as it had poorer results at 4 and 6 mm compared to MTA Fillapex and AH Plus, respectively.

Clinical Approach to Pulp Canal Obliteration: A Case Series

This article describes four cases with safe and feasible clinical treatment strategies for anterior teeth with pulp canal obliteration (PCO) using cone-beam computed tomography (CBCT), digital radiography (DR), dental operating microscopy (DOM) and ultrasonic tips (US). Four anterior teeth with PCO were chosen. DR was taken with different angulations and analyzed with different filters. Subsequently, the access cavity was performed with the aid of DOM. If the canal was not identified, CBCT was requested. Sagittal and axial slices guided the direction of the ultrasonic tips. After identification of the canal, it was then negotiated and instrumented with the rotary instruments. All four canals were successfully identified, with no complications. In case 1, the canal was identified using DR, DOM and US tips. In cases 2, 3 and 4, the canals were identified with DR, DOM, US tips and CBCT. Complete root canal obliteration identified in radiography did not necessarily mean that pulp tissue was not visible clinically, either. The clinical evaluation of the access cavity with the aid of MO was crucial. If the canal was not identified, CBCT was mandatory in order to show more detailed view of the precise position of the canals, their directions, degrees of obstruction and dimensions. It served as a guide for the direction of the ultrasonic tips to keep them within the pulp chamber safely, with a low risk of iatrogenic injury.

Aplicação clínica do laser em endodontia

The comprehension of the phenomena that involves laser/ tissue interaction is of fundamental importance, since each specific wavelength reacts with the tissue in a different way, providing multiple applications, such as in controlling pulp vitality, pulp capping and pulpotomy, root canal preparations, surgical interventions and postoperative repair. In Endodontics, investigations with different types of Lasers have been conducted in order to enable safe parameters for its clinical application to be established. The aim of this article is to show the current indications of Laser in Endodontics through the analysis of scientific articles. Key words: Endodontics. Laser. Dental pulp. Laser therapy.

Avaliação da infiltração coronária em próteses provisórias utilizando diferentes agentes cimentantes

Forty-five central maxillary incisors extracted from human beings were selected. After having undergone standard chemico-mechanical preparation, these incisors were filled with the calcium hydroxide dressing, together with saline solution, in 5mm apicals. After sectioning of the crowns, temporary restorations with intraradicular retainers were fixed with Dycal, Temp Bond and Lysanda. The entire external surface of the roots and crowns, except for a 2mm area near the cervical adaptation, was made impermeable. After being immersed in a 2% Rodamine B solution for 7 days, the specimens were longitudinally sectioned, and infiltrations were analyzed. All results were submitted to pertinent statistical analysis. None of the cements tested was capable of impeding dye infiltration.