The assessment of orthodontic bonding defects: Optical coherence tomography followed by three dimensional reconstruction

Orthodontic bonding is a simple yet important procedure that can influence the outcome of treatment in case it is performed incorrectly. An orthodontic treatment shadowed by repeated bonding failures can become unduly long and will decrease patient trust and compliance. Optical coherence tomography has been widely used in ophtalmology but is relatively new to dentistry. Using OCT one can detect aerial inclusions within the orthodontic adhesive or even identify incongruence between the bracket base and the tooth surface. The aim of our study was to identify bonding defects and reconstruct them three-dimensionally in order to be able to characterize them more accurately. We bonded 30 sound human permanent teeth with ceramic orthodontic brackets using a no-mix self-curing orthodontic adhesive. Prior to bonding all teeth were stored in tap water at 4°C and then professionally cleaned with rotary brushes and pumice. The samples were processed by the same person and the rotary brushes were changed after every fifth tooth. All interfaces were investigated by means of OCT and 4 defects were found. Subsequently, the defects were reconstructed threedimensionally using an open-source program. By identifying and reconstructing bonding defects we could assess the quality of the bonding procedure. Since bonding tends to be more accurate in vitro where the environmental conditions are close to ideal, it is probable that defects found in vivo be even greater in number, which leads to the conclusion that this type of investigation is potentially valuable. © 2011 SPIE

En-Face optical coherence tomography and fluorescence in evaluation of orthodontic interfaces

Bonding has become a routine procedure in several dental specialties - from prosthodontics to conservative dentistry and ven orthodontics. In many of these fields it is important to be able to investigate the bonded interfaces to assess their quality. All currently employed investigative methods are invasive, meaning that samples are destroyed in the testing procedure and cannot be used again. We have investigated the interface between human enamel and bonded ceramic brackets non-invasively, introducing a combination of new investigative methods - optical coherence tomography (OCT), fluorescence OCT and confocal microscopy (CM). Brackets were conventionally bonded on conditioned buccal surfaces of teeth. The bonding was assessed using these methods. Three dimensional reconstructions of the detected material defects were developed using manual and semi-automatic segmentation. The results clearly prove that OCT, fluorescence OCT and CM are useful in orthodontic bonding investigations

Technological aspects, numerical simulation and noninvasive imagistic approach on resin bonded fixed partial prosthesis

Working with resin bonded fixed partial prosthesis could lead a rapid debonding in some cases. This study try to evaluate the possibilities to reduce the problems in that kind of fixed partial prosthesis

Orthodontic bonding of tooth colored brackets from a different perspective: An optical coherence tomography investigation

Bracket bonding has become routine procedure in fixed orthodontics over the past couple of decades. The choice whether to receive ceramic or polycarbonate brackets is mainly the patient's but the issues related to bonding them are part of the practitioner's responsibility. Recurrent bracket debonding can unduly prolong treatment or even lead to compromised results. Therefore, we collected human extracted premolars and bonded them with aesthetic brackets and investigated them by a new, non-invasive method - optical coherence tomography (OCT) in order to assess the quality of the bracket-tooth interface. The OCT investigation revealed a series of gaps within the adhesive at the bracket-tooth interface

Marginal adaptation of ceramic veneers investigated with en-face optical coherence tomography

The aim of this study was to analyze the quality of marginal adaptation and gap width of Empress veneers using en-face optical coherence tomography. The results prove the necessity of investigating the marginal adaptation after each veneer bonding process

OCT and RX Validation of metal-ceramic crowns repaired with ceramic material

Objective: Study's objectives are focused on non-invasive OCT and RX investigations, of interfaces obtained after repairing a metal-ceramic crown with ceramic materials. Material and method: In this study 40 metal-ceramic crowns were involved. Each crown is restoring the first central incisor 1.1. Metallic infrastructure was performed from nickel-chrome WIRON 99 BEGO alloy, and Kiss Ceramic. The defects of 3x3mm were created into ceramic material in the buccal-incisal area with a grinding instrument. The samples were divided into two groups and the defects were reconstructed with two different types of ceramic materials: Kiss and Vita Omega. The interfaces between crown and ceramic material used for reparation were Rx and OCT investigated which are both non-invasive, imagistic investigation techniques. For better investigation three-dimensional reconstructions were performed. Results: The interfaces showed defects for both systems used. Major defects such as gaps could be identified at the ceramic-ceramic interface. Also material defects could be observed at the areas of congruence between the two ceramic materials and smaller defects along the interfaces. The defects were present into the deep and superficial layers of interface. The OCT system used a length wave of 1300nm and worked in B-scan mode along the interfaces to be studied while the C-scan mode was only used at the defect areas. Rx investigation detected the macro defects. Conclusions: Time Domain OCT and RX systems were identifying the faulty areas after repairing artificially created defects, of metal-ceramic crowns with ceramic material, hereby enabling us to establish recommendations for the clinical use. © 2011 SPIE