Enamel Surface Roughness after Debonding: A Comparative Study using Three Different Burs.

AIM: To compare effects of three different burs, i.e., tungsten carbide bur, composite bur, and fiber glass bur on the surface roughness of enamel after debonding evaluated by means of profilometry. MATERIALS AND METHODS: The present study was conducted in the Department of Orthodontics and Dentofacial Orthopedics, Guru Nanak Dev Dental College and Research Institute, Sunam, Punjab, India, from August 2011 to December 2012 on 36 extracted premolars. After mounting the samples in acrylic blocks with their buccal surfaces exposed, initial measurement of the surface roughness was made using profilometry. Teeth were then etched and brackets were bonded with light cure adhesive. After 3 days, the brackets were debonded using three different rotating burs at low speed, i.e., tungsten carbide bur, fiber glass bur, and composite bur. Enamel surface roughness values were obtained and assessed using paired t-test, one-way analysis of variance (ANOVA) test, and post hoc multiple tests. RESULTS: Surface roughness of enamel increased significantly for tungsten carbide bur when compared with fiber glass bur and composite bur. But there was no significant difference in the surface roughness value when fiber glass bur was compared with the composite bur. CONCLUSION: Composite and fiber glass burs used for resin removal after orthodontic debonding produced a smoother enamel surface as compared with the tungsten carbide bur. CLINICAL SIGNIFICANCE: After an orthodontic treatment, restoring the enamel surface to its pretreatment condition without inducing any iatrogenic damage after debonding is a clinical challenge. Residual resin removal through proper means ensures a smooth surface, and, hence, a plaque-free environment. Finishing requires as much planning and execution as planned for the fixed therapy itself.

Comparison of stability changes of various palatal implants.

AIM: The aim of this study was to comparatively evaluate stability changes in palatal implants during the early stages of bone healing with chemically modified sandblasted/acid-etched (modSLA) titanium surface compared with a standard sandblasted (SLA) titanium palatal implants. MATERIALS AND METHODS: A statistically significant number (n = 40; 24 females and 16 males) of adult subjects who volunteered and have their informed consent for participating in the study were selected. These volunteers were randomly allocated to the experimental group (modSLA surface) and to the control group (SLA surface) with 20 subjects in each group. Documentation of implant stability was done by assessing resonance frequency analysis (RFA) at implant insertion, followed by subsequent assessments each week till 12th week from baseline (1-12 weeks). RFA values were expressed as an implant stability quotient (ISQ). RESULTS: Immediately after installation of implant, the ISQ values for both surfaces tested were not significantly different and yielded mean values of 75.28 ± 5.23 for the control and 73.16 ± 4.81 for the test surface. In the first 2 weeks after implant installation, both groups presented only small changes and thereafter a reducing trend in the mean ISQ levels. In the test group, after 4 weeks a tendency toward increasing ISQ values was observed, and 6 weeks after surgery the ISQ values corresponded to those after implant insertion. For the SLA control group, the trend changed after fifth week and yielded ISQ values corresponding to the baseline after ninth week. After 12 weeks of observation, the test surface yielded significantly higher stability values of 78.68 ± 2.9 compared with the control implants of 75.5 ± 3.19, respectively. CONCLUSION: The results undoubtedly support and validate the potential for chemical modification of the SLA surface to positively influence the biologic process of osseointegration and also a faster healing.

Radiographic Evaluation of the Hyoid Bone Position and Pharyngeal Airway Depth in Anteroposterior Dysplasia.

INTRODUCTION: The pharyngeal airway, tongue, and hyoid bone are correlated. The hyoid bone is connected to the pharynx, mandible, and cranium through muscles and ligaments and its position with respect to them determines the tongue posture and function. It also plays an important role in maintaining the airway and upright natural head position. Different skeletal patterns have different morphologies and shapes of the mandible, which might be affected by the position of the hyoid bone and the pharyngeal airway depth. This cephalometric study was conducted to relate the pharyngeal airway depth and the hyoid bone position of different skeletal patterns in sagittal dimension, and it determines and compares the linear parameters of the pharyngeal airway depth in Class I, II, and III malocclusion groups and anteroposterior, vertical, and angular positions of the hyoid bone positions in Class I, II, and III malocclusion groups. MATERIALS AND METHODS: Lateral cephalometric radiographs selected for study were divided into three groups of 30 samples each based on ANB angle and ß angle into skeletal Class I, Class II, and Class III, respectively. Five linear measurements for the pharyngeal airway depth, four linear measurements for anteroposterior position, two linear measurements for vertical position, and one angular measurement for angular hyoid bone position were made. RESULTS: The pharyngeal airway depth was found to show no statistically significant difference between Class I and Class III malocclusions. The pharyngeal airway depth in Class II malocclusion was found to be statistically smaller at D1 as compared to that in Class I and Class III malocclusions, whereas it remained the same at the rest of the locations measured, i.e., D2, D3, D4, and D5. The Class III malocclusion group showed a significant statistical difference in the anteroposterior hyoid bone position at all levels (i.e., H1, H2, H3, and H4) as compared to the Class II malocclusion group, whereas it showed a statistically significant difference as compared to the Class I malocclusion group at H1 and H3. The angular inclination of the hyoid bone in the Class II malocclusion group showed a statistically significant difference with the Class I and Class III malocclusion group but the Class III malocclusion group showed no significant difference statistically when compared to the Class I malocclusion group. CONCLUSION: The pharyngeal airway depth in the Class II malocclusion group was also found to be narrower at the superiormost level measured at the posterior nasal spine from the posterior pharyngeal wall. The hyoid bone position was variable in angular and anteroposterior dimensions among different malocclusion groups. HOW TO CITE THIS ARTICLE: Chauhan R, Bagga DK, et al. Radiographic Evaluation of the Hyoid Bone Position and Pharyngeal Airway Depth in Anteroposterior Dysplasia. Int J Clin Pediatr Dent 2019;12(2):101-106.