Alceu Berbert

A methodology for evaluation of root canal instrumentation.

We present a methodology for comparing root canalanatomy before and after root canal instrumentation. The root canal anatomy prior to instrumentation serves as the control. This method enables one to obtain information for statistical analysis.

The Influence of ultrasound in removing intraradicular posts

Thirty single-rooted teeth were prepared to receive cast posts. After cementation of the post the teeth were divided into three groups. Group I did not receive any treatment, whereas the posts in groups II and III were treated with an ultrasonic device, for 2 min and 5 min, respectively. The force required for post removal was determined using a universal test machine. No statistical differences (P > 0.05) were found between the groups where ultrasound had been used. Significantly reduced forces were necessary to remove the posts from group II and III, compared with group I which did not receive ultrasonic treatment (P < 0.05).

Root perforations dressed with calcium hydroxide or zinc oxide and eugenol

Root perforations were experimentally made at the furcation level in 15 maxillary and mandibular dogs premolars. A group of these perforations were dressed with an aqueous paste of calcium hydroxide and iodoform; another group was dressed with zinc oxide and eugenol; and in a third group (control) the perforations were kept open. After a 90-day postoperative interval, the dogs were killed and their teeth and neighboring structures processed for histopathological analysis. In those teeth dressed with calcium hydroxide, necrosis in front of the perforation and different levels of cementum hyperplasia were observed. The specimens dressed with zinc oxide and eugenol showed inflammatory reactions with abscess formation and resorption of the alveolar crest. In the opened perforations these same phenomena were also frequently seen.

Effect of calcium hydroxide in powder or in paste form on pulp-capping procedures: Histopathologic and radiographic analysis in dog's pulp

The pulps of seventy dog teeth were evaluated histopathologically and radiographically following intentional exposure and treatment with either a calcium hydroxide powder or a calcium hydroxide paste prepared with distilled water. The results were recorded after periods of 2, 30, 70, and 120 days. No differences were detected in the pulpal responses to direct pulp capping achieved with a calcium hydroxide paste and with a calcium hydroxide powder.

The use of bovine mandibles for teaching endodontic surgical skills

Summary The bovine mandible is a simple practical model for teaching endodontic surgical techniques.