Quality of CAD-CAM inlays placed on aged resin-based composite restorations used as deep margin elevation: a laboratory study

Abstract

Objectives To assess the impact of the age of resin-based composite (RBC) restorations used for deep margin elevation (DME) on the marginal quality and fracture resistance of inlays. Materials and methods Permanent human molars with direct RBC restorations, involving the mesial, occlusal, and distal surface (MOD), were allocated to four groups (each n = 12). Half of the teeth underwent thermomechanical loading including 240,000 occlusal load cycles and 534 thermal cycles (TML, 5 °C/55 °C; 49 N, 1.7 Hz). With RBC left in one proximal box as DME, all teeth received MOD inlays, made from lithium disilicate (LDS) or a polymer-infiltrated ceramic network material (PICN). The restored teeth underwent TML including 1.2 million occlusal cyclic loadings and 2673 thermal cycles. The marginal quality was assessed at baseline and after both runs of TML. Load-to-fracture tests were performed. The statistical analysis comprised multiple linear regressions (α = 0.05). Results Simulated aging of RBC restorations had no significant effect on the marginal quality at the interface between the RBC and the tooth and the RBC and the inlay (p ≥ 0.247). Across time points, higher percentages of non-continuous margin were observed between the inlay and the tooth than between the tooth and the RBC (p ≤ 0.039). The age of the DME did not significantly affect the fracture resistance (p ≥ 0.052). Conclusions Artificial aging of RBC restorations used for DME had no detrimental effect on the marginal quality and fracture resistance of LDS and PICN inlays. Clinical relevance This laboratory study suggests that—in select cases—intact, direct RBC restorations not placed immediately before the delivery of an indirect restoration may be used for DME.

Influence of Proximal Box Elevation Using Two Different Resin Composite Viscosities on The Marginal Adaptation of CAD/CAM Ceramic Overlays Subjected to Thermomechanical Aging. An In Vitro Study

“…Artificial aging is known to have a detrimental effect on both composite and ceramic restorations. (25) Thus, for proper simulation of the oral conditions, cyclic loading in addition to thermal cycling were done to all samples in this study. The second null hypothesis for this study was rejected as, our results showed that thermomechanical aging significantly affected the marginal adaptation in all study groups as the marginal gap was significantly higher after thermomechanical aging in all samples.…”

“…For control group (Group C); no PBE was done. (25) All prepared samples were checked with digital caliper, then, with silicon index and periodontal probe. Teeth were scanned with intraoral scanner (OmniCam, Dentsply Sirona GmbH, Germany), and the image was superimposed with preoperative scan for reduction verification with PrepCheck feature on CEREC 4.5 software (Dentsply Sirona GmbH, Germany), samples with discrepancy > 0.2mm were excluded.…”

“…Followed by 75,000 cyclic loading of 50 N occlusal load at 1.6 Hz frequency in chewing simulator (ROBOTA, Model ACH-09075DC-T, AD-TECH TECHNOLOGY CO., LTD., GERMANY). (25) Vertical Marginal gap was re-assessed after thermomechanical aging utilizing the same reference points on each sample and with the same magnification. All data were collected, tabulated and statistically analyzed.…”

Elevación de margen profundo, Revisión sistemática

“…Para lograr los propósitos de esta técnica desde el su lanzamiento hasta la fecha se han propuesto diferentes materiales para logar su fin desde cementos (9), ionómeros de vidrio (4,5,13), y los más nuevos como ionómeros de vidrio modificados con resina (5,8,13), híbridos de vidrio (4), compuesto de resina convencional (5,6,12,(15)(16)(17)(18)(19)(20)(21), compuesto de resina en bloque (5,7), compuestos bioactivos (13), compuestos de resina fluida (6,10,15), compuestos de resina fluida en bloque (7,10,11). No obstante, persiste la ausencia de acuerdo en lo que respecta al material de elección y la técnica de aplicación del material para realizar la elevación de margen profundo, esta se sintetiza en obtener una buena adaptación marginal, minimizando la microfiltración entre el diente y la restauración llamados espacios interfaciales.…”

Elevación del margen profundo: Una revisión bibliográfica de la adaptación y resistencia a la fractura

“…El propósito del DME es facilitar la impresión, la colocación del dique de goma y la cementación de la restauración indirecta y a pesar de que existen limitaciones asociadas a esta técnica como la profundidad de la cavidad, el tipo de relleno para la elevación del margen, la vitalidad dental, entre otros factores, diversos estudios respaldan la efectividad de esta técnica. (Dietschi & Spreafico, 1998;Da Silva et al, 2021;Theisen et al, 2023).…”