Enamel cracks evaluation —A method to predict tooth surface damage during the debonding

Abstract

The objective of this in vitro study was to evaluate the effect of the enamel cracks on the tooth damage during the debonding. Measurements of the cracks characteristics (visibility, direction, length, and location) were performed utilizing a scanning electron microscopy (SEM) technique and mathematically derived formulas (x=h/30, l=n*x) before and following the removal of mechanically retained metal and ceramic brackets. The likelihood of having greater extent enamel defects was higher for the teeth with pronounced cracks (odds vatios, OR=3.728), increased when the crack was located in more than one zone of the tooth (OR=1.998), and the inclination did not exceed 30-45° (OR=0.505). Using ceramic brackets the risk of greater amount tooth structure defects raised 1.45 times (OR=1.450). Enamel crack showing all these characteristics at the beginning of the orthodontic treatment and the use of ceramic brackets might predispose to higher risk of greater extent tooth surface damage after the debonding by 20.4%.

Enamel Surface Roughness after Lingual Bracket Debonding: An In Vitro Study

“…Enamel reduction that might occur during debonding may compromise tooth resistance, creating enamel cracks and fractures in combination with increasing surface roughness [12,13]. This may lead to plaque accumulation resulting in caries development.…”

Polymerization Shrinkage and Spherical Glass Mega Fillers: Effects on Cuspal Deflection

“…As previously demonstrated by other Authors (14), the presence of a C-factor particularly unfavorable, as in the case of the inlays with a good marginal fit, the shrinkage stress developed from thin composite cement thickness, is efficiently dissipated by the deformability (compliance) of the substrate to which it is adherent. In our experimental model both the C-factor and the compliance were particularly favorable because the modulus of elasticity (E) of the acrylic resin (2.65 GPa) is much lower than dentin (18.3 GPa) (2,8,11,14). Thus our finding may be attributable to the high compliance of the substrate that is able to compensate the resulting shrinkage stress.…”

“…The development of this tensile force, along the adhesive interface, can result in deformation of the cavity walls if the adhesion force is strong enough, conversely it determines the separation of the restoration from the tooth. If the thickness of the residual dental tissue is thin, it may also occur of the enamel fracture (enamel crack) when this latter is not sufficiently supported by the dentin (11). This phenomenon, together with the flow that the composite undergoes, during the setting reaction, at the level of the free surface of the restoration, which is not subject to adhesion, limits the negative effects of stress but does not cancel them completely (12,13).…”

Enamel microcracks in terms of orthodontic treatment: A novel method for their detection and evaluation

“…1. The buccal enamel surfaces of all the teeth included in the study (both from the younger and older age group) were examined employing SEM (TM-1000, Hitachi, Tokyo, Japan) 9,12,13) . The SEM was operated at 15 kV, at ≤5×10 −2 Pa (electron gun vacuum) and at ~30-50 Pa (specimen chamber vacuum).…”

“…EMCs, quite often visible by the naked eye, may jeopardize the integrity of the enamel, cause stain and plaque accumulation on the rough fractured surface, thus increasing susceptibility to carious lesions and compromising the appearance of the teeth [6][7][8] . Studies have shown that the bracket removal procedure is related with the EMCs increase and formation of new EMCs [9][10][11][12][13] . Various methods, such as transillumination, staining, ultrasound, or optical coherence tomography (OCT) have been described in the literature for EMCs detection [14][15][16][17] .…”