Er∶YAG激光脱粘接处理对全瓷修复材料性能影响研究OACSTPCD

Objective To evaluate the influence of Er∶YAG laser debonding on the color,translucency,surface micro-hardness,and flexural strength of all-ceramic materials.Methods The research was conducted between March to Octo-ber 2023 at the Fujian Key Laboratory of Oral Diseases.Totally 40 short specimens measuring 10.0 mm × 10.0 mm × 1.5 mm and 20 long specimens measuring 20.0 mm × 4.0 mm × 1.5 mm were fabricated using yttria-stabilized tetragonal zirconia polycrystals(3Y-TZP and 5Y-TZP)and zirconia-reinforced lithium silicate(ZLS),respectively.The speci-mens received surface treatment and were then randomly divided into control and experimental groups,with each group containing 20 short specimens and 10 long speci-mens of different types of all-ceramic materials.Totally 60 complete,caries free human third molars extracted because of periodontitis or orthodontic treatment in the Depart-ment of Oral and Maxillofacial Surgery of the Affiliated Stomatological Hospital of Fujian Medical University from Janu-ary to March 2023 were collected for dentin specimens preparation.The specimens in the experimental group were adhe-sives bonding to dentin and Er∶YAG laser debonding treatment,while the control group received no further processing.The L*,a*,and b*values of both experimental and control groups were measured using a spectrophotometer,and the col-or differences(ΔE00)and translucency differences(ΔTP00)between the two groups were calculated.The surface microhard-ness and flexural strength of the specimens in both groups were measured using a microhardness tester and universal test-ing machine,respectively.Scanning electron microscopy(SEM)was used to observe the microstructures of the surfaces and bonding interfaces of the specimens before and after debonding.Results The ΔE00 values between the experimental and control groups of 3Y-TZP and 5Y-TZP were 0.54±0.07,and 1.13±0.36,respectively.These values were below the perceptibility thresholds of color change(1.30).Similarly,the ΔTP00 values for the same groups were 0.22±0.23 and 0.33±0.63,respectively,falling below the perceptibility thresholds of translucency differences(0.62).For ZLS,the ΔE00 values and ΔTP00 values were 1.76±0.78 and 0.80±0.90,respectively.Both of these values were exceed the perceptibil-ity thresholds but below the acceptable thresholds(ΔE00=2.25,ΔTP00=2.62).There were no significant differences in surface microhardness and flexural strength of the specimens in the experimental and control groups for all materials(P＞0.05).SEM images revealed minor ablation-like surface alterations on the outer surface of ZLS in the study group,while no notable changes were observed on the bonding interfaces of ZLS specimens,as well as the outer surface and bonding interfaces of 3Y-TZP and 5Y-TZP specimens compared to the control group.Conclusion The Er∶YAG laser debond-ing treatment exhibited no discernible impact on the color and translucency of 3Y-TZP and 5Y-TZP.Moreover,the treat-ment did not affect the surface microhardness and flexural strength of 3Y-TZP,5Y-TZP,and ZLS.These findings indi-cated that all-ceramic restorations can be reused clinically after undergoing Er∶YAG laser debonding.