Repair strength and surface topography of lithium disilicate and hybrid resin ceramics with LLLT and photodynamic therapy in comparison to hydrofluoric acid

Abstract

Aim: The aim was to compare the repair bond strength and surface topography of lithium disilicate ceramics (LDC) and hybrid resin ceramics (HRC) using different surface conditioning treatments [low level laser therapy (LLLT), photodynamic therapy (PDT), hydrofluoric acid (HF) with silane and air abrasion (AA) and silane]. Material and method: Sixty specimens each of LDC and HRC were used. Discs were prepared for each group (6 × 2 mm), conditioned using different regimes. Specimens in group 1 and 5 were laser irradiated using Er,Cr:YSGG (ECYL), group 2 and 6 were conditioned using methylene blue photosensitizer (PDT), group 3 and 7 surface was treated with hydrofluoric acid and silane (HFA-S), group 4 and 8 conditioned with Al2O3 air abrasion and silane (AA-S). A Porcelain Repair Kit was used according to manufacturer recommendation in all samples. Peak universal bond adhesive was rubbed on ceramic surface and then bonded with composite resin. For shear bond strength testing the specimens were placed in a universal testing machine. A stereomicroscope at 40x magnification was used to analyse failure pattern. Five specimens in each group after surface treatment were evaluated for surface changes and topography using scanning electron microscopy. The mean repair bond strength was calculated using ANOVA and Tukey’s post hoc test at a significance level of ( p < 0.05). Result: The highest repair bond strength was observed in group 3 (LDC) (20.57 ± 3.58 MPa) (HFA-S), whereas, the lowest score was displayed in Group 2 (LDC) using methylene blue photosensitizer (MBPS) (12.18 ± 1.08 MPa). Similarly, in HRC the highest repair SBS was presented in group 8 (AA-S) (20.52 ± 2.51 MPa) and the lowest SBS values were exhibited by PDT treated group 6 (13.22 ± 0.62 MPa). Conclusion: A combination of mechanical and chemical surface treatments should be used in order to achieve adequate repair bond strength between resin composites and ceramic interface of LDC and HRC.

RETRACTED: Comparison of adhesive bond strength among fiber reinforced post and core with different cementation techniques: In vitro study

“…The failure analysis was performed using SEM and digital microscope (Hirox KH 7700, Tokyo, Japan). 4 The failure were classified as adhesive, cohesive, or admixed.…”

“…3 All these factors contribute to the reduced stiffness and fracture resistance of the tooth. 4 Therefore, restoring and retaining such compromised structure necessitates the post-placement for retention and adhesion of coronal restorations. 3,5 Traditionally, cast metal posts are used to retain core buildup on root canal treated teeth (RCT).…”

Influence of Toothbrush Abrasion and Surface Treatments on Roughness and Gloss of Polymer-Infiltrated Ceramics

“…The lust of gloss achieved often depends upon composition, filler size, and type of surface treatment. Studies have demonstrated that materials such as LAVA Ultimate are composed of discrete and clustered nanoparticles whose size is smaller than the wavelength [12,28]. Studies have suggested that filler size smaller than light wavelength allows the reflection of light fully, without influencing the gloss effect [25].…”

“…Nevertheless, the physiochemical fusion of the ceramic and resin matrix with varying ratios has evolved this vulnerability. The optical phenomenon of the gloss effect is achieved through a reflection of light that depends on the surface capacity and surface roughness governed by the composition [11,12]. The glassy network in ceramics has demonstrated greater power to allow reflected light to pass; hence, the aesthetic stability of the composites is lower than that of the ceramics [2,5].…”

“…Nevertheless, to enhance the surface quality and appearance, dentists follow three steps in their clinical practice: polishing, staining, and glazing [12]. To reduce the surface energy, enhance the luster, and mimic natural tooth appearance, the dentist recommends restorative polishing with varying levels of abrasives and composition.…”