Surgical endodontic reintervention using a modern technique: 2 case reports.

Management of post-treatment apical periodontitis after surgery--assuming the tooth is restorable, periodontally sound, and the patient desires to retain it--includes nonsurgical retreatment and surgical reintervention. This article presents 2 cases of surgical reintervention using a modern surgery technique that utilized an operating microscope, ultrasonic tips, and biocompatible materials. After the reinterventions were performed, adequate periradicular healing was observed in both cases. These cases reinforce the precept that combining knowledge about the biologic aspects of endodontics with surgical endodontic treatment using a modern technique is a predictable treatment option.

Ultra-structural changes at the apical stop irradiated with CO2 laser.

OBJECTIVE: This study evaluated ultra-structural dentine changes at the apical stop after CO(2) laser irradiation used during biomechanical preparation. BACKGROUND: Most studies evaluating the sealing efficiency of CO(2) lasers have been carried out after apical root canal resections and retro-filling procedures. METHODS: Sixty human canines were prepared with #1 to #6 Largo burs. The apical stops were established at 1 mm (n = 30) and 2 mm (n = 30) from the apex. Final irrigation was performed with 1% NaOCl and 15% EDTA followed by 20 ml of distilled and deionized water. Specimens were subdivided into three subgroups (n = 10 for each stop distance): GI- no radiation (n = 20); GII- 3W potency (n = 20), GIII- 5W potency (n = 20). After preparation, specimens were evaluated by scanning electron microscopy, with ultra-structural changes classified according to a scoring system based on six qualitatively different outcomes. RESULTS: Statistical analysis using the Mann-Whitney test confirmed more intense results for the specimens irradiated at 5 W potency than at 3 W (p < 0.0001). The Kruskal-Wallis test indicated that when using the same potencies (3 or 5 W) at 1 and 2 mm from the apex, there were no statistically significant differences in ultra-structural changes. CONCLUSIONS: Our results showed that ultra-structural changes ranged from smear layer removal to dentine fusion. As laser potency was increased from 3 to 5 W, ultra-structural changes included extensive fused lava-like areas sealing the apical foramen.

Permeability of different groups of maxillary teeth after 38% hydrogen peroxide internal bleaching.

This study evaluated the influence of internal tooth bleaching with 38% hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38% H2O2. The bleaching agent was applied to the buccal surface and to the pulp chamber for 10 min. This procedure was repeated 3 times. The specimens were processed histochemically with copper sulfate and rubeanic acid, sectioned longitudinally, and digitalized in a scanner. The area of stained dentin was measured using Image Tool software. Data were analyzed statistically by ANOVA and Tukey's HSD test (alpha=0.05). There was statistically significant difference (p<0.001) among the untreated groups, CI (0.23 +/- 0.26) having the lowest permeability and LI (10.14 +/- 1.89) the highest permeability. Among the bleached groups, dentin permeability was increased in all groups of teeth except for 2PM. It may be concluded that bleaching with 38% H2O2 affected dentin permeability near the pulp chamber in maxillary anterior teeth and in first and second premolars.

Permeability of different groups of maxillary teeth after 38 percent hydrogen peroxide internal bleaching

This study evaluated the influence of internal tooth bleaching with 38 percent hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38 percent H2O2. The bleaching agent was applied to the buccal surface and to the pulp chamber for 10 min. This procedure was repeated 3 times. The specimens were processed histochemically with copper sulfate and rubeanic acid, sectioned longitudinally, and digitalized in a scanner. The area of stained dentin was measured using Image Tool software. Data were analyzed statistically by ANOVA and Tukey's HSD test (?=0.05). There was statistically significant difference (p<0.001) among the untreated groups, CI (0.23 ± 0.26) having the lowest permeability and LI (10.14 ± 1.89) the highest permeability. Among the bleached groups, dentin permeability was increased in all groups of teeth except for 2PM. It may be concluded that bleaching with 38 percent H2O2 affected dentin permeability near the pulp chamber in maxillary anterior teeth and in first and second premolars.

Este estudo avaliou a influência do clareamento interno com peróxido de hidrogênio (H2O2) a 38 por cento na permeabilidade da dentina coronária de dentes anteriores superiores e pré-molares superiores. Quatorze incisivos centrais (IC), incisivos laterais (IL), caninos (C), primeiros (1PM) e segundos (2PM) pré-molares foram seccionados transversalmente e distribuídos em 2 grupos (n=7) sendo: G1: não receberam tratamento e, G2: clareados com aplicação de gel na face vestibular e câmara pulpar por 10 min, repetido 3 vezes. Os espécimes foram processados histoquimicamente por meio de imersão em sulfato de cobre e ácido rubeânico e digitalizados em escaner. A área corada foi aferida (Programa Image Tool). Os dentes que não receberam tratamento, apresentaram diferença estatisticamente significante (p<0,001), sendo o ICS (0,23 ± 0,26) e o ILS (10,14 ± 1,89) os grupo com os menores e os maiores valores de permeabilidade, respectivamente. Quando clareados, a permeabilidade coronária dos grupos dentais foi aumentada, exceto no grupo do 2PM. Concluiu-se que a permeabilidade da dentina coronária nos dentes anteriores superiores e primeiros pré-molares foi alterada pelo clareamento dental interno.

Tratamento de dentes traumatizados com rizogênese incompleta: apicificação / Treatment of traumatized teeth with incomplete apex: apexification

Introdução e objetivo: Buscou-se apresentar dois casos clínicos de dentes traumatizados cujos ápices se apresentavam radiograficamente abertos e cujos elementos dentais estavam sem fratura. Relato de caso: Nesses casos, a instrumentação deve ser realizada com leve pressão do instrumento contra as paredes, em virtude da pequena espessura delas. Sendo assim, a escolha da solução irrigante torna-se fundamental, uma vez que suas propriedades químicas específicas suprirão a deficiência do preparo mecânico. Curativos à base de hidróxido de cálcio e propilenoglicol foram feitos e trocados em períodos de 7 dias, 15 dias, 3 trocas a cada 30 dias e uma troca após 3 meses, até a formação de barreira apical calcificada, período no qual se obturou o canal com a técnica de cone único e cimento Grossman. Conclusão: A conduta clínica utilizada proporcionou a formação de barreira apical calcificada, restituindo o equilíbrio biológico e funcional da estrutura dental e garantindo o sucesso do tratamento.

Introduction and objective: Two cases reports of traumatized teethwith incomplete apexes and no tooth fracture. Case report: In these cases, instrumentation should be performed with no pressure to the walls due to the decreased thickness, therefore, the irrigating solution is fundamental to achieve ideal biomechanical preparation. Calcium hydroxide intracanal dressings between sessions were applied at 7 days,15 days, 3 changes every 30 days and a change after 3 months, until apical barrier formation, and sealing of the root canal with the single gutta-percha point technique with Grossman´s cement. Conclusion: The used clinical protocol efficiently formed the calcified root barrier and biological and functional equilibrium was achieved guaranteeing the treatment success.

Efficacy of ultrasound in removal of intraradicular posts using different techniques.

The efficacy of ultrasound in removing cast metal posts was evaluated in this in vitro study using one or two ultrasound units and ultrasonic vibration for various lengths of time. The crowns of 30 healthy maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the root canals were treated endodontically. The canals were prepared and their impressions were taken with self-curing acrylic resin. After casting with copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with Panavia F resin cement. The specimens were divided into five groups. In groups I and II, only one ultrasound unit was used for 30 and 60 s, respectively; in groups III and IV, two ultrasound units were used simultaneously for 30 and 60 s, respectively; in group V, ultrasound was not used (control). Ultrasonic vibrations were applied with an Enac OE-5 ultrasound unit and an ST-09 tip. All samples were subjected to traction on an Instron machine (model 4444) at a cross-head speed of 1 mm/min. Analysis of the results revealed a statistically significant difference between the groups (ANOVA, P < 0.01); however the difference between groups II and IV was not statistically significant. The efficacy of ultrasound in removing intraradicular posts was confirmed, and the most effective technique was the use of two ultrasound units, independent of the length of time ultrasound was applied.

Avaliação in vitro das alterações promovidas em canais radiculares artificiais curvos após instrumentação com as técnicas ápico-cervical e cérvico-apical / An in vitro evaluation of changes in curved artifical root canals after instrumentation with step-back and crown-down techiniques

O presente trabalho teve por objetivo verificar, in vitro, as alterações promovidas pelos preparos dos canais radiculares artificiais curvos com instrumentos de aço inoxidável (Dyna instruments), cotejando as técnicas: ápico-cervical e cérvico-apical. Foram avaliados os desgastes ocorridos em três níveis: 2, 4 e 11 milímitros do final apical do canal simulado, assim como as áreas apical e cervical da parte curva. Nos níveis analisados, foi verificado que ocorreu diferença estatisticamente significante em 5%, no nível de 2 milímetros, e 15 para o nível de 4 milímetros. Para o nível de 11 milímetros, não houve diferença significativa. Para a área apical da curvatura foi observada significância em 1%, e para a área cervical, resultado estatisticamente significante em 5%. Foi concluido que baseados na metodologia empregada, os preparos no sentido cérvico-apical tendem a diminuir a ocorrência de acidentes em canais radiculares artificiais curvos, produzido preparos mais centrados em relação aos canais simulados instrumentados pela técnica ápico-cervical.

Avaliação in vitro das alterações promovidas em canais radiculares artificiais curvos após instrumentação com limas de níquel-tiânio e aço inoxidável / An in vitro evaluation of root canal preparation performed with nickel-titanium and stainless steel instruments

O presente trabalho teve por objetivo verificar, in vitro, as alterações promovidas pelos preparos dos canais radiculares artificiais curvos com instrumentos de aço inoxidável (Dyna Instruments) e de niquel-titânio (Dyna Instruments). Foram avaliados os desgastes ocorridos em três níveis: 2,4 e 11 milímetros aquém do final apical do canal simulado, assim como as áreas apical e cervical da parte curva. Nos níveis analisados, foram verificadas diferenças estatisticamente significantes em 1 por cento. Para área apical de curvatura, foi observada significância em 5 por cento e para area cervical, resultdos estatisticamente significantes em 1 por cento. Foi concluido que, baseado na metodologia empregada, os preparos realizados com limas de níquel-titânio mantém o canal simulado mais centrado, desgastando menos resina nas áreas analisadas, prevenindo a formação de deformações

Temas de endodontia: cirurgia de acesso endodôntico.

Descreve sobre a cirurgia de acesso endotontico.