Micro-grooved surface laser texturing of zirconia: Surface characterization and artificial soft tissue adhesion evaluation

Despite the reported high success of dental implants, problems related to biofilm formation and peri-implantitis due to the entrance and proliferation of bacteria on the peri-implant zone have increasing attention. In this sense, this work proposes a new zirconia surface with micro-grooves aiming to develop an effective tight seal between artificial soft tissue and implant surface and thus, to protect from bacterial invasion. In this study, different laser and design parameters were tested to produce successive micro-grooves with different and variated depth, width and wall. The micro-grooves were produced by a Nd:YAG laser and were morphologically characterized by SEM. Higher marked depths were obtained for a high number of laser passages under low scan speed as a result of a high amount of laser energy density. The most adequate conditions were mechanically tested regarding their capacity to retain artificial soft tissue (mimicking natural gingiva) by mechanical tensile strength test. The strength of adhesion between soft tissue and the micro-grooved surface revealed to be strongly dependent on the depth and width. The obtained results showed that the production of successive micro-grooves on the zirconia surface increased the adhesion of artificial soft tissue to its surface, proving that laser technology is a promising approach for the manufacturing of implants with micro-grooves sites that can protect from bacterial invasion.