Surface modification of zirconia or lithium disilicate-reinforced glass ceramic by laser texturing to increase the adhesion of prosthetic surfaces to resin cements: an integrative review

Abstract

Objective The purpose of this study was to perform an integrative review on laser texturing the inner surface of lithium disilicate-reinforced glass ceramic or zirconia to increase their bond strength to resin-matrix cements. Materials and method A bibliographic review was performed on PubMed using the following search terms: “zirconia” OR “lithium disilicate” AND “laser” AND “surface” OR “roughness” AND “bond strength” AND “luting agent” OR “resin cement.” Studies published in English language until March 15, 2023, were selected regarding the purpose of this study. Results A total of fifty-six studies were identified althoug thirteen studies were selected. The findings revealed that zirconia surfaces were significantly modified after laser irradiation resulting in macro-scale aligned retentive regions with depth values ranging from 50 to 120 µm. Average roughness values of laser-textured zirconia by Er,Cr:YSGG laser (~ 0.83 µm) were quite similar when compared to grit-blasted zirconia surfaces (~ 0.9 µm) although roughness increased up to 2.4 µm depending on the laser type and parameters. Lithium disilicate-reinforced glass ceramics textured with Er:YAG revealed an average roughness of around 3.5 µm while surfaces textured using Nd:YAG laser revealed an average roughness of 2.69 µm; that was quite similar to the roughness values recorded for etched surfaces (2.64 µm). The shear bond strength (SBS) values of zirconia surfaces textured on Nd:YVO4 laser irradiation were slightly higher (~ 33.5 MPa) than those recorded for grit-blasted zirconia surfaces (28 MPa). Laser-textured zirconia surfaces on CO2 laser revealed higher SBS values (18.1 ±0.8 MPa) than those (9.1 ± 0.56 MPa) recorded for untreated zirconia surfaces. On lithium disilicate-reinforced glass ceramics, higher SBS values to resin-matrix cements were recorded for specimens textured with a combination of fractional CO2 laser irradiation and HF acid etching (~ 22–24 MPa) when compared with grit-blasted specimens (12.2 MPa). Another study revealed SBS values at around 27.5 MPa for Er:YAG-textured lithium disilicate-reinforced glass ceramics to resin-matrix cements. Conclusions The laser irradiation at high power increases the roughness of the inner surface of lithium disilicate-reinforced glass ceramic or zirconia leading to an enhanced bond strength to resin-matrix cements. Thus, the laser type and irradiation parameters can be adjusted to enhance the macro- and micro-scale retention of zirconia and glass ceramic surfaces to resin-matrix cements. Clinical relevance Alternative methods for surface modification of lithium disilicate-reinforced glass ceramic and zirconia surfaces have been assessed to provide proper morphological aspects for enhanced adhesion to resin-matrix cements. An increase in the bond strength of glass ceramics or zirconia to resin-matrix cements can improve the long-term performance of cemented prosthetic structures in the oral cavity.

Bonding Pretreatment of Aesthetic Dental CAD-CAM Materials through Surface Etching with a Mixed Aqueous Solution of Ammonium Fluoride and Ammonium Hydrogen Sulfate

“…Extensive research has been conducted to improve the surface treatment methods for these materials. Techniques such as plasma irradiation [ 18 , 19 ], sandblasting [ 20 , 21 ], tribochemical coating [ 22 , 23 ], laser abrasion [ 24 , 25 ], and chemical etching [ 26 , 27 ] have been examined for their ability to modify material surfaces for better bonding with luting agents. Among these methods, chemical etching with hydrofluoric acid (HF) is notable for its efficiency in etching silica-containing materials [ 17 , 28 ] such as lithium disilicate glass, feldspathic porcelain, polymer-infiltrated ceramic networks, and resin composites.…”

Chemical etching of CAD-CAM glass-ceramic-based materials using fluoride solutions for bonding pretreatment

“…Extensive studies and experimentation have been conducted to refine surface treatment methods for glass-ceramic-based materials. Various techniques, including plasma irradiation 13,14) , airborne-particle abrasion 15,16) , laser abrasion 17,18) , and chemical etching 19,20) , have been explored for modifying the material surface to improve bonding with the luting agent. Among these methods, chemical etching with hydrofluoric acid (HF) shows high efficiency in etching material surfaces 12) .…”

The Effects of a Biomimetic Hybrid Meso- and Nano-Scale Surface Topography on Blood and Protein Recruitment in a Computational Fluid Dynamics Implant Model

“…Recent advances in laser technology have allowed the simultaneous generation of meso- and nano-topographies on metallic surfaces [ 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. Particular studies utilizing solid-state laser etching created a unique meso-and-nano hybrid zirconia surface on which the meso-topography mimics “cactus-like” oscillating spikes, while the nano-topography consists of dense, nodular protrusions, 100–300 nm in diameter, resembling trabecular bone [ 45 , 46 ].…”