Adherence to a strict endodontic surgical protocol and the use of contemporary techniques and materials will result in a predictably successful outcome in a wide range of teeth.

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, chloroform. 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.

No abstract

The purpose of this study was to compare the effects of smooth and diamond-coated ultrasonic retrotips on the external and internal surfaces of root-end preparations with the aid of a scanning electron microscope (SEM). Forty-four mesial roots of human mandibular molars were selected. The canals were cleaned, shaped and obturated using gutta-percha and sealer. The apical portions were resected at a 45 degrees-angle bevel exposing both mesial canals and the isthmus area. The roots were then divided into two groups according to the type of root-end preparation: Group A--performed with smooth retrotips (S) and Group B--performed with diamond-coated retrotips (DC). The specimens were coded and prepared for SEM evaluation. Observations of the external surface preparation showed that the S and DC retrotips produced very well-centered cavities involving both canals and isthmus area with minimal deviations and no perforative defects. When the internal surface of the root-end preparations was evaluated, it was evident that the use of S retrotips resulted in clean canal walls with little superficial debris and smear layer. Internal canal surfaces done with DC retrotips were irregular showing patent grooves, in contrast with the more uniform, regular and smoother surfaces when S retrotips were employed.

Regeneration of bone defects remains a clinically important problem in many instances. This paper reports on the use of membrane technique combined with decalcified freeze-dried 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.