Effectiveness of the Canal Finder and hand instrumentation in removal of gutta-percha root fillings during root canal retreatment / Efetividade do Canal Finder e da instrumentação manual na remoção de preenchimentos por guta-percha durante o retratamento do canal radicular

The purpose of this study was to quantify the amount of remaining gutta-percha/sealer on the canal walls when the Canal Finder system, hand instrumentation and a combination of both (hybrid technique) were used to remove these materials. The amount of apically-extruded debris and the time required for removal were also recorded. Sixty extracted maxillary anterior teeth were prepared using a stepback technique and obturated with gutta-percha. Reinstrumentation of all groups was done in conjunction with a solvent, chloro-form. The teeth were split longitudinally and photographed, and the total area of the root canal and the area of the debris were traced and quantified using a computerized image analysis system. The ratio of remaining obturation material to root canal surface was derived and analysed statistically. Hand instrumentation resulted in less debris remaining than did the other two techniques (P<0.05). The differences in the amount of apically extruded debris were not significant among the techniques (P>0.05). The hybrid technique required significantly less time for filling material removal. The canal finder system alone was not superior to hand instrumentation

Barreiras isolantes no clareamento dental ambulante: efeito na permeabilidade dentinária cervical / Effects of the walking bleach on dental permeability

A proposta desse estudo foi avaliar aos efeitos da técnica de clareamento "ambulante" na permeabilidade dentinária cervical, após o uso de barreiras isolantes. Quarenta e seis caninos superiores foram preparados, obturados e divididos em três grupos: (A) sem barreira (controle), (B) Cavit, (C) Scothbond MP + resina Z-100. Todos os dentes foram então clareados, três vezes com intervalo de sete dias, e então imersos em solução aquosa de azul de metileno por três dias. Duas secções foram feitas em cada dente ao nível da junção de cemento esmalte, por vestibular e proximal. Cada secção foi fotografada e acoplada a um sistema computadorizado de análise de imagem (Bioquant), e a infiltração do corante quantificada de duas maneiras: 1) área total infiltrada, 2) infiltração externa. Foi então estabelecida uma porcentagem média de infiltração para 1 e 2, nos dois níveis (proximal e vestibular). Análise estatística foi realizada através de ANOVA (p = 0.01) e teste de Scheffé. Os resultados evidenciaram que barreiras de Scothbond MP + resina foram significantemente mais efetivas que os outros dois grupos, enquanto que o Cavit foi significantemente superior ao grupo sem barreira

Ridge argmentation following extraction of replanted central incisor / Aumento da crista ossea após reimplante de incisivo central

Regeneration of bone defects remains a clinically important problem in many instances. This paper reports on the use of membrane technique combined with decalcified freezedried bone allograft to promote bone formation after extraction of a replanted central incisor with extensive root resorption. The procedure prevented ridge reduction, both buccolingually and apicocoronally, and will facilitate prosthetic replacement of the lost tooth without esthetic problems

Endodontic retreatment of thermafil or lateral condensation obturations in post space prepared teeth / Retratamento endodôntico após obturação com Thermafil ou condensação lateral em dentes preparados com a técnica \"Post space\"

The purpose of this study was to quantify the amount of remaining gutta-percha/sealer after retreatment of post space prepared teeth obturated with a lateral condensation technique or with Thermafil with plastic and metallic carrier. The time required for retreatment was also recorded. Forty-five extracted mandibular premolars were prepared using a step-back flared technique and obturated. The post space was prepared and a 5-mm obturation was left in the canal. Retreatment of all groups was done using a solvent technique. The teeth were split longitudinally and photographed. The total area of the canal and the area of gutta-percha/sealer were traced on white paper. Both areas were quantified using a computerized image analysis system and the ratio of remaining obturation material to root canal periphery was derived and statistically analyzed. Statistical analysis (analysis of variance, p = 0.01) showed no differences among the techniques when the average percentage of remaining gutta-percha/sealer was compared. Results revealed that the Thermafil metallic retreatment group consumed significantly more time than the others (analysis of variance, Scheffe p = 0.01). The metallic carriers were not easily removed from the canals, six metal carriers could not be retrieved during the retreatment routine