Effect of ER, CR: YSGG laser debonding on enamel surface changes in stainless steel and ceramic brackets - An in-vitro study.

AIM: The aim of this in-vitro study was to observe and analyze the various enamel surface changes that occur due to laser debonding of metal and ceramic brackets, done by means of Er, Cr:YSGG laser. MATERIALS AND METHODS: 90 extracted premolars were randomly allocated into one of six groups with 15 teeth each. The groups represent metal brackets (Groups A1, A2, A3) and ceramic brackets (Groups B1, B2, B3). Each sub-group represents the mode of debonding used in the study. Debonded teeth were analyzed under scanning electron microscopy (SEM) at 80X and at 1000X magnification at three sites. The adhesive remnant index (ARI) scores were analyzed and the presence of enamel damage was observed. RESULT: ARI showed high score in Groups A1 and B1. SEM images of large composite remnants at the site of bracket in Groups A1 and B1 at the site of bracket and multiple enamel microcracks and fractures at interface and enamel adjacent to bracket in Groups A1 and B1. SEM images of minimal composite remnants at the site of bracket in Groups A2, A3, B2, and B3 and little to no presence of enamel microcracks or fractures at interface and enamel adjacent to bracket in Groups A2, A3, B2, and B3. CONCLUSION: The use of Er, Cr:YSGG laser in orthodontic practice, especially in the debonding procedures of orthodontic brackets provide quality care to patient with minimal post-treatment damages.

SIDS plane: A simple and innovative alternative to Frankfurt horizontal plane.

AIMS AND OBJECTIVES: To derive a new horizontal plane which can be a suitable alternative to Frankfurt horizontal plane (FH plane). MATERIALS AND METHODS: 200 pre-treatment lateral roentogenic cephalograms from patient records in the department of orthodontics and dentofacial orthopaedics were traced. The landmarks were identified and marked and the measurements were carried out. Patients with all skeletal relationships were included in the study. The angle formed between the lines connecting anatomic porion, orbitale and machine porion was measured and tabulated. Dimorphism between the genders if any was also evaluated. RESULTS: The mean angulation between the planes from the anatomic porion to orbitale to machine porion (PoA-Or-PoM) in our sample is 3.14 ± 2.17°. PoA to Or to PoM angulation for males is 2.57° and for females is 3.4°. CONCLUSIONS: SIDS plane also called as derived FH plane given here is a reliable and easily reproducible alternative to the FH plane.