Debonding characteristics of orthodontic brackets subjected to intraoral stresses under different adhesive regimes: An in-vitro study

Abstract

Aim: To evaluate the effect of simulated intraoral hydraulic, thermal, and mechanical stresses on the debonding characteristics of orthodontic brackets under different adhesive regimes. Materials and methods: Groups of pre-coated (G1) and non-coated (G2) orthodontic metal brackets were bonded onto the buccal surfaces of 96 premolars using etch-and-rinse (SG1, n = 24) and self-etch (SG2, n = 24) primers. Twelve specimens (C1) from each subgroup were subjected to early debonding resistance tests, while the other twelve (C2) were used to test delayed debonding resistance after exposure to conditions simulating intraoral hydraulic, thermal, and mechanical stresses. The debonding resistance of the brackets was evaluated using a universal testing machine and the debonding patterns were micro-visualized to determine the adhesive remnant indexes of subgroups of specimens. Results: Within each group, the etch-and-rinse primer (SG1) resulted in higher debonding resistance than self-etch primers (SG2) ( p < 0.05), while there was no difference between non-stressed and stressed specimens ( p > 0.05). Within each category of test specimens, there was no difference between pre-coated (G1) and non-coated (G2) brackets ( p > 0.05). The tested specimens in all categories showed comparable adhesive remnant indexes. However, higher percentages of favorable scores (0 and 1) were obtained for all stressed specimens. Conclusions: Short-term cumulative intraoral stresses have no adverse effect on the debonding values of either pre-coated or non-coated brackets when either etch-and-rinse or self-etch primer is used for bonding. Exposure of the bonded brackets to different types of stress reflects favorable debonding patterns.

Bond Strength Survival of a Novel Calcium Phosphate-Enriched Orthodontic Self-Etching System after Various Ageing Protocols: An In Vitro Study

“…There was a nonsignificant effect of the different ageing models on SBS for both the control and nHAp-SEP groups. The TSEP group survived all artificial ageing protocols recording the highest mean SBS values [ 27 , 30 ]. However, bracket bonding with TSEP yielded significantly higher ARI scores with traumatic debonding after ageing (18 cracked or damaged enamel surfaces).…”

The Effect of Potassium Iodide Application on the Bond Strength of Orthodontic Brackets Bonded to Silver Diamine Fluoride Pretreated Dentin - “An In-Vitro Study.”

“…25,26 Previously, it was declared that the minimum required bond strength value for clinically successful bracket bonding is 5.9-7.8 MPa. 11,27 Results of the present work showed insignificant difference in bond strength of the adhesive junction between the bracket and the tooth substrate when dentin was treated with SDF in comparison to the untreated dentin. This was in agreement with previous study stated that application of SDF had no effect on the bond strength between the resin composite materials and sound dentin.…”

“…Easier debonding of orthodontic brackets is more favorable and resulting in lower adhesive remnant indices (ARIs). 27,32 The low ARI score was validated by the adhesive mode of failure which indicates a relatively lower bond strength of the adhesive to the sound dentin in comparison to its bond strength to orthodontic brackets.…”

Influence of preoperative degree of tooth loosening and thickness of wire on the rigidity of wire composite splint

“…[ 1 16 17 ] In the present study, all these methods were employed to achieve varying DoL in the LDI model. Teflon tape was used to simulate periodontal ligaments[ 10 ] because of its resiliency and ease of application over the root surface in contrast to autopolymerizing silicon used in previous studies. [ 18 ] Three coatings of 0.075 mm thick Teflon tape were used to reproduce the average dimensions of PDL.…”

“…The root surface of right central incisor (tooth 11) was circumferentially wrapped with three coat of 0.075 mm Teflon tape (Swimline Hydrotools, Edgewood) to simulate periodontal ligaments. [ 10 ]…”