[Sealant microleakage evaluation of three common fissure preparation methods]

Statement of Problem: In order to decrease microleakage, several preparation methods and cleaning techniques are used on the tooth surface before sealant application has been advocated. These techniques are pumice prophylaxis, fissure enameloplasty, adhesive, laser and air abrasion

Purpose: The purpose of this in vitro study was to evaluate microleakage of three different preparation techniques before acid etching and pit and fissure sealant application

Materials and Method: Sixty extracted sound third molars were randomly divided into 4 groups of 15 each. The teeth were prepared using 1 of the 3 occlusal surface treatments, 1] traditional pumice prophylaxis 2] fissure enameloplasty 3] air abrasion and acid etching. Then the sealant [Clinpro] was applied on the occlusal fissures of all the teeth based on the manufacturer's recommendations. The teeth were thermocycled between 5 and 55 degrees C for 500 cycles with a dwell time of 30 seconds and then stored in normal saline. All the teeth were sealed apically and coated within 1.5 mm of the sealant margin with two layers of nail varnish. They were then immersed in a 0.5% solution of fushin for 24 hours to allow dye penetration into the possible gaps between the enamel and sealant. Buccolingual cuts were made parallel to the long axis of the tooth. The surfaces were scored 0 to 2 for the extent of microleakage using a stereomicroscope. The results were analyzed through mann-Withney test and Mann-Whitney U test

Results: Pretreatment with air abrasion produced the lowest microleakage scores. In the control group, 46.7% microleakage was shown, in the pumice prophylaxis group 40% and in the enameloplasty group 53.3%. There was no significant difference in microleakage between the 3 fissure preparation methods prior to sealant placement [p >0.05]

Conclusion: Neither air abrasion nor enameloplasty followed by acid etching produced significantly less fissure sealant microleakage as compared to the traditional pumice prophylaxis technique

[Comparison of the accuracy of two methods of age estimation based on radiography of the developing teeth]

Statement of Problem: Dental age estimation methods are used in the treatment plan and identification of the age of unknown corps and skulls. One of the methods of age estimation is Foti method which is based on regression analysis of dental variables [number of tooth germs and erupted tooth] for which four models have been proposed

Purpose: The aim of the present study was to compare the dental age derived from these four methods with the Demirjian method on the basis of chronological age

Methods and Material: In this cross-sectional descriptive study, 150 panoramic radiographs of 90 girls and 60 boys aged 6-20 years were studied. The variables required for regression analysis were derived from clinical examinations and panoramic radiographs. Demirjian age was determined using panoramic radiographs

Results: The mean chronological age was 10.74 +/- 3.02, Demirjian age 11.16, +/- 2.76, model one 11.57 +/- 1.61, two 11.44 +/- 2.35, three 11.53 +/- 2.49 and four 11.24 +/- 1.85 years. The comparison between chronological age, Demirjian age and regression models showed a statistically significant difference. The obtained ages from Demirjian methods and regression models were shown to be overestimated

Conclusion: A positive association was found between the real ages and age estimates derived from these four models. The equations allow age estimation in specific situations [such as when only either the maxillae or mandible is available or when the radiography is not available]

[Effect of bonding agent on sealant microleakage in saliva-contaminated enamel]

Many clinical studies have reported on the success of sealants with respect to caries reduction. Saliva contamination during the procedure is the main reason in sealant's failure. The aim of this study is to evaluate the effect of two types of adhesive [Excite, Prompt-L-Pop] on reducing sealant microleakage in saliva-contaminated enamel. In this experimental study, 40 intact premolar teeth were chosen and divided into four groups. Group 1: the teeth were etched and sealed with sealant without any contamination. Groups 2 and 3: The teeth were etched and exposed to saliva for 10 seconds, and air-dried. Consequently, a bonding agent [Excite, Prompt-L-Pop] was applied prior to the sealant application and curing. Group 4: After being etched and contaminated, the teeth were sealed without any bonding agent. After some processes the teeth were bucolingualy sectioned and the samples were evaluated under stereomicroscope. The findings were statistically analyzed, using Kruskal-Wallis and Mann-Whitney tests. The results showed that the amount of microleakage in the saliva contaminated fissure sealant without bonding agent group had a significant difference with the sealant without saliva contamination group [p <0.05]. Besides, there was no significant difference in the amount of microleakage between Excite, Prompt-L-Pop groups and the non-contaminated fissure sealant group. Exposing the enamel to the saliva after acid etching and prior to sealant application would increase the microleakage significantly. Using Excite and Prompt-L-Pop, the dentin adhesives, after salivary contamination would decrease the microleakage to the extent of non-salivary contaminated fissure sealant group

[Dietary habits and caries risk prevalence in pre-term and low birth weight children]

Complications due to the prematurity may affect the infant's development and feeding pattern. Improper feeding practices carry a risk of developing dental caries in pre-term and low birth weight children [PLBW].The aims of this study were to determine and compare the prevalence of caries in 3-4 year old PLBW children in comparison with normal birth weight children [NBW], and to evaluate the impact of dietary habits on the development of dental caries in primary teeth.A cross-sectional study including dental examination and questionnaire survey was carried out at a number of clinics in Isfahan, Iran. For this study, 100 children, 42 girls and 58 boys with the mean age of 40.5 +/- 4.25 months were randomly selected. Clinical examinations were carried out to determine dmft. Informations regarding birth weight, pregnancy period, age, gender and feeding habits were drawn from questionnaires. The data were analyzed by Mann-Whitney and Chi-square test.The mean dmft was found to be 4.23 +/- 3.97. PLBW children with a mean dmft of 59 +/- 4.05 had a significantly higher dmft over NBW children [3.27 +/- 3.85] p < 0.05. Breast feeding, duration of breast feeding, and number of meals and snacks per day were significantly greater in NBW children p < 0.05. The PLBW children were significantly more likely to eat sugar and use bottle than NBW children A clear relationship exists between dietary habits and PLBW children. Targeted infant feeding programs and education with regard to dental hygiene is of great importance to avoid dental caries in PLBW children