RESUMO
Pit and fissures are the most common affected sites of caries occurance in newly erupted first permanent molars, however effectiveness of sealants are questionable in these teeth, due to difficulties in moisture control. The purpose of this study was to evaluate and compare the impact of two different categories of dentin bonding agents on sealant performance. 56 pairs of sealants [122 teeth] were placed bilaterally and randomly on the occlusal surface of both upper and lower first molars with either dentin bonding agent. With no preparation of the surface, Adper prompt or Excite both were applied as one layer and cured before sealant placement. Caries assessment was performed according to the CCC method [Color, Coverage, Caries] introduced by Deery et al. [2001] at 6-month intervals for 12 months. Partially or totally lost sealants were replaced at each recall visit. Data were analyzed using the Wilcoxon test. Total etch and Excite were significantly superior in both retention and caries prevention [P=0.0001]. Excite showed a significantly greater retention in the mandible than maxilla [P=0.027], whilst Adpaer prompt showed no difference between the jaws.. Among the teeth whose sealants were lost, progression of caries was greater in the Adper Prompt group. According to findings of this study, application of total-etch and bond is preferred to self-etch adhesives before sealant application in newly erupted first permanent molars
RESUMO
Paraoxon is an organophosphate. Organophosphate inhibit acetylcholinestrase enzyme and cause nicotinic and muscarinic sings. There is no study on our knowledge regarding the effect of these substances on gastric acid and pepsin secretion. In the present study, the effect of acute consumption of paraoxon on gastric acid and pepsin secretion has been investigated. In the present study 30 female N-mari rats weighing 200-250gr were used. The first group [paraoxon] received 0.5mg/kg paraoxon intraperitonealy. The second group [alcohol] received the dozes of ethyl alcohol [96%] and the third group [control] received no drug. Animals were anesthetized by intraperitoneal injection of 50mg/kg Sodium thiopental. After trachesotomy and laparatomy gastric secretions were collected with a tube via duodenum. Pentagastrin [25 micro g/kg. ip] was used as gastric stimulator. Acid and pepsin secretions were measured by titration and Anson methods respectively. Stages of measurement were basal, stimulated. and re-basal. The basal acid secretion in control, alcohol and paraoxon groups was 7.6 +/- 0.26, 7.46 +/- 0.4 and 7.03 +/- 0.28 micro mol/15min respectively that shows no significant difference among three groups. Although following pentagastrin-stimulation acid secretion was significantly more than basal stage in all groups, but there was significantly more secretion in control than alcohol subjects. But there was no difference between control and paraoxon or alcohol and paraoxon groups in this regard. Regarding pepsin secretion, there was significantly more secretion in alcohol subjects than others in all measured stages. In comparison to control group, acute paraoxon has no effect on basal acid pepsin secretion, while acute alcohol caused a significant increase in basal acid/pepsin secretion