Diagnóstico e tratamento restaurador com resina composta e matriz oclusal em molar com lesão de cárie oculta / Diagnosis and restorative treatment with composite resin and occlusal matrix on molar with occult caries lesion

Atualmente, o diagnóstico de cárie tem sido mais difícil em razão do aparecimento de pacientes com cáries ocultas nos dentes posteriores, sendo necessários métodos auxiliares capazes de proporcionar ao dentista segurança quanto à intervenção restauradora. Este trabalho teve como objetivo demonstrar, com um relato de caso clínico, a utilização do aparelho DIAGNOdent® (Kavo) como método auxiliar no diagnóstico de cárie oculta num primeiro molar inferior e a técnica restauradora direta com resina composta com auxílio de uma matriz oclusal em acrílico autopolimerizável (AU).

Currently the diagnosis of caries has been more difficult due to the presence of patients with occult caries in the posterior teeth, so ancillary methods are necessary to provide the dentist safety regarding restorative intervention. The objective of this study was to demonstrate through a clinical report, the use of the DIAGNOdent® (Kavo) device as an aid in the diagnosis of occult caries in a lower first molar and the direct restorative technique with a composite resin using an Acrylic self-curing occlusal matrix (AU).

Influence of Light Irradiation Through Zirconia on the Degree of Conversion of Composite Cements.

PURPOSE: To assess the light irradiance (LI) delivered by two light-curing units and to measure the degree of conversion (DC) of three composite cements and one flowable composite when cured through zirconia or ceramic-veneered zirconia plates with different thicknesses. MATERIALS AND METHODS: Three dual-curing composite cements (Clearfil Esthetic Cement, Panavia F2.0, G-CEM LinkAce) and one light-curing flowable composite (G-aenial Universal Flo) were investigated. Nine different kinds of zirconia plates were prepared from three zirconia grades (YSZ: Aadva and KATANA; Ce-TZP/Al2O3: NANOZR) in three different thicknesses (0.5- and 1.5-mm-thick zirconia, and 0.5-mm-thick zirconia veneered with a 1.0-mm-thick veneering ceramic). Portions of the mixed composite cements and the flowable composite were placed on a light spectrometer to measure LI while being light cured through the zirconia plates for 40 s using two light-curing units (n = 5). After light curing, micro-Raman spectra of the composite films were acquired to determine DC at 5 and 10 min, 1 and 24 h, and at 1 week. RESULTS: The zirconia grade and the thickness of the zirconia/veneered zirconia plates significantly decreased LI. Increased LI did not increase DC. Only the Ce-TZP/Al2O3 (NANOZR) zirconia was too opaque to allow sufficient light transmission and resulted in significantly lower DC. CONCLUSION: Although zirconia-based restorations attenuate the LI of light-curing units, the composite cements and the flowable composite could be light cured through the YSZ zirconia. LI is too low through Ce-TZP/Al2O3 zirconia, necessitating the use of self-/dual-curing composite cements.

Bond strength and micro-computed tomographic evaluation of pre-coated brackets.

OBJECTIVES: The aim of the present study was to assess and compare the shear bond strength (SBS) of metal pre-coated orthodontic brackets bonded to fluorotic and non-fluorotic teeth treated with three different etching techniques. A second aim was to determine the volume of adhesive remaining on the tooth at debond using micro-computed tomography (µCT). METHODS: Ninety extracted premolars were selected to include 45 fluorotic (test group) and 45 non-fluorotic (control group) teeth. Each group was divided into three subgroups of 15 each, which were treated as follows: 1) micro-etched; 2) acid-etched; and 3) both micro-etched and acid-etched. A bonding agent was applied to the prepared surfaces; pre-coated and light-cured brackets were attached to all teeth. An Instron universal testing machine was used to record the debonding force. Specimens were then scanned using a microCT to evaluate the amount of adhesive remaining on the teeth. The significance of the statistical tests was pre-determined at p < 0.05. RESULTS: Two-way ANOVA showed that fluorosis of teeth had no influence on the SBS (p = 0.165) whereas the volume of adhesive remnants was significantly higher in the control group compared with the test group (p < 0.001). CONCLUSIONS: Fluorosis had no influence on the SBS of brackets, whereas it had a negative influence on retaining adhesives onto the tooth surfaces.