Six-year clinical evaluation of fissure sealants placed after mechanical preparation: a matched pair study.

The occlusal fissures of 61 matched pairs of first permanent molars in children aged 6-9 years were sealed. The experimental tooth of each pair was prepared mechanically by running a #1 round bur in the fissure area. After 6 years, 34 pairs were available for examination. Of 19 pairs of mandibular molars sealed, 4 molars of the control and 2 of the experimental groups sustained partial or total loss of sealant. Of 15 pairs of maxillary molars sealed, 2 molars in the experimental group lost their sealants, whereas 8 molars in the control group sustained partial or total sealant loss. It was concluded that mechanical preparation resulted in a significantly higher retention rate of sealants placed on maxillary molar teeth. Reports 1,2 have demonstrated a decline in the retention rates of fissure sealants with increasing time. A previous report has shown an increased retention rate following mechanical preparation of the fissure of maxillary teeth; this study had a follow-up period of 3 years. 3 The purpose of the present report is to present 6-year data for retention of fissure sealants applied in a matched pair experimental design where the experimental molars were sealed following mechanical preparation of the fissures. Methods and Materials Forty-seven children residing in a nonfluoridated area (< 0.3 ppm) with paired caries-free, contralateral first permanent molars were selected from 200 first and second graders (mean age 7 years) attending school dental clinic in a Jerusalem suburb. By the end of the sixth year, 23 children (49%) were available for re-examination. All clinical procedures and follow-up examinations were carried out in the school dental clinic. The children were examined by the authors and a consensus diagnosis was reached in every case. Criteria and rationale of this study methodology have been reported previously. 3 The treatment procedure was explained to the parents and oral consent obtained before treatment. The experimental tooth was chosen randomly by a toss of a coin. This group was treated by mechanically preparing the fissure using a #1 round steel bur at low speed, in order to remove plaque and organic debris from the fissure, and to remove surface enamel. The surface then was cleaned with a slurry of pumice, etched for 1 min, and sealed with Delton a according to the manufacturer’s instructions, using cotton roils for isolation. After polymerization, the marginal adaptation and retention of the sealants were checked by trying to pry the sealant off with an explorer. When re-examined, the teeth were rinsed, air-dried, and examined with an explorer to detect the degree of sealant retention (recorded as total retention, partial loss, or total loss). Sealant failure was defined when the material was partially or totally lost, or when an amalgam restoration was replacing the sealant; success was defined when the sealant was retained fully and covered all available fissures. At the time of the examination the examiners did not know which was the control and which was the experimental tooth. From the original 61 pairs of molars treated, 34 were available for examination after 6 years; of these 34 pairs, 19 were in the mandible and 15 in the maxilla. None of the children include4 in this study were treated in a private practice during the period of this clinical trial; this fact decreased the probability of resealing by another dentist. The McNemar binomial test was used for the statistical analysis. 4