This study examines the treatment of non-vital immature permanent incisors using the calcium hydroxide apexification technique. The objectives of the present study were to determine the speed and location of barrier formation and those factors discernible at presentation and during treatment which may be related to it. Forty-four non-vital immature incisors undergoing calcium hydroxide apexification were reviewed in detail. All cases were reviewed every 8-12 weeks for up to 18 months, or until apexification occurred. Details of the time and nature of the injuries and treatment were recorded. The degree of apical development prior to treatment was assessed, and barrier formation, location and time were noted. Mean time to barrier formation was 34.2 weeks (range 13-67 weeks). The strongest predictor of rapid barrier formation was the rate of change of calcium hydroxide and a barrier also formed more rapidly in cases with narrower initial apical width. There was evidence of displacement and a higher mean time for barrier formation in half of the cases. The presence of an abscess was the weakest predictor of rapid barrier formation and the effect was not significant (P = 0.280). The barrier was located at the apex in 28 cases (63.6%) and the distance from the barrier to the apex for the remaining 16 (36.4%) varied from 1 mm to 5 mm. The number of placements of calcium hydroxide varied from 1 to 4 with a mean of 1.9, and there was a higher mean number of calcium hydroxide placements in the cases where the barrier was located at the apex.
External inflammatory resorption and replacement resorption are complicating factors that may result from traumatic dental injuries when the tooth is luxated or avulsed and replanted. Resorption may, ultimately, result in loss of the tooth. However, with appropriate treatment, the prognosis for these teeth is greatly improved, with the possibility of preventing or arresting resorption. The purpose of this paper is to review these trauma entities, to discuss factors that influence the occurrence of resorption and to describe the most appropriate treatment. A case is presented, illustrating both resorption entities, but with varying outcomes.
Summary.
Objectives. To study barrier formation in nonvital, immature permanent incisors being treated using the apexification technique in two centres, and to establish the effect of the frequency of change of calcium hydroxide (CaOH) on barrier detection times.
Design. A retrospective study of the time of detection and the position of barriers.
Results. There were no significant differences between the two centres in terms of the average frequency of change of each CaOH dressing, the distribution of barrier detection times or the position of barriers (P > 0·05). There was a total of 107 teeth and the time of barrier detection was significantly earlier in more frequently dressed teeth (P = 0·013). Of the teeth with a barrier detection time of less than 9 months, 60.7% were dressed more frequently than every 3 months, as opposed to 39·1% of teeth with longer barrier times (P = 0·027). The mean time of barrier detection for all cases was 43·3 weeks. The majority of barriers were located at or near the apex.
Conclusion. The frequency of change of CaOH can increase the speed of barrier detection but does not appear to affect the position.
OBJECTIVES. This study sought to identify the strategies used by syringe exchange programs to establish their legality. METHODS. Statutes, court decisions, published studies of exchange programs, and news stories were reviewed, and telephone interviews were conducted with syringe exchange personnel. RESULTS. Twenty-seven exchanges have been authorized by amendments to or judicial interpretations of state drug laws or by administrative action under such laws, or operate in a state that has no laws regulating needles. At least 13 programs operate under claims of legality based on local interpretations of state law, principally public health law. The remaining syringe exchanges operate without a claim of legality. CONCLUSIONS. The deployment of syringe exchanges has been hindered by concerns about their legal status. This study shows that the applicability of drug laws to syringe exchange is open to dispute, and that local public health authorities may under some circumstances rely on their own legal authority to fund or operate syringe exchange programs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.