Mechanical properties of endodontic posts.

Twenty-two commercially available endodontic posts were examined with regard to stiffness, elastic limit and resistance to fracture. Differences in mechanical properties were explained by differences in width, shape and surface structure. In the selection of an endodontic post, its stability rather than its retention should be of primary clinical concern. Accordingly, the authors advocate the use of endodontic posts that have a cylindrical coronal portion and a conical apical portion.

[Bleaching of discolored root canal treated teeth. 3- and 5-year postoperative results]. / Blegning af misfarvede rodfyldte taender. Resultater efter 3 og 5 års observationstid.

In this study a simple and time-saving method for internal bleaching of discolored root-filled teeth is presented. The method used sodium perborate moistened with water and the access cavity temporarily sealed with Cavit between visits. Bleaching was carried out in 95 teeth, with a satisfactory initial result in 90% of the cases. After 3 years of observation, recurrence of discoloration was found in 20% of the teeth seen at follow-up examination. After 5 years of observation a total of 29.4% showed discoloration or recurrence of discoloration. The method is easy, fast and essentially without complications. It is therefore recommended as an alternative to full crown restoration, assuming the tooth is not too weakened because of large fillings.

Pulp condition of successfully formocresol-treated primary molars.

The aim of the study was to assess the state of the pulp of primary teeth successfully treated by formocresol pulpotomy. Nineteen teeth, all of them with clinically and radiographically successful treatments, were extracted 3-24 months after treatment. The pulpal condition had changed in all the teeth. Inflammatory reaction or necrosis was observed in all teeth. Dentinal resorption followed by apposition of hard tissue were common findings. In the teeth with vital tissue only in the apical area, the tissue had minor or no signs of inflammation. Microorganisms could be demonstrated in the necrotic tissue in one tooth. The wide range of pulpal conditions observed indicated that there was no typical tissue reaction to formocresol even though treatment was clinically successful. The present study confirms that the formocresol method should be regarded only as a means to keep primary teeth with pulp exposures functioning for a limited period of time.

Bacteria in cavities beneath intermediary base materials.

The ability of six different intermediary base materials to prevent bacterial entrance beneath silicate cement fillings was investigated in vivo in primary molars. After an observation period of 1 month, bacteria were found on the pulpal wall in two out of 10 cavities beneath Fluoritec and four out of 10 cavities beneath Durelon solid mixed, De Trey phosphate cement solid or creamy mixed. Beneath the intermediary base materials Dycal, zinc oxide-eugenol cement, Dropsin and Durelon creamy mixed, no bacteria were found. In cavities filled with silicate cement or silver amalgam only, bacteria were observed in nine out of 10 and in five out of 10 cavities, respectively.