In Vitro Study on Effects of Water-air Cooling Mode and Laser Energy Parameters on Efficiency and Safety of Er:YAG Laser in Ceramic Veneer Removal

doi:10.13701/j.cnki.kqyxyj.2026.07.007

Abstract

Abstract: Objective: To investigate the effects of water-air spray cooling modes and laser energy parameters of erbium doped yttrium aluminum garnet (Er:YAG) laser in veneer removal and its safety regarding both soft and hard dental tissues. Methods: An in vitro veneer bonding model was established. Specimens were randomly assigned to two groups based on the presence or absence of water-air spray cooling: Group A (no cooling) and Group B (with cooling). In each group, five incremental energy levels of Er:YAG laser irradiation were applied (Group A: 60-140 mJ; Group B: 140-220 mJ, n=4 per level) until veneer debonding. The debonding time and changes in pulpal chamber temperature were recorded. The tooth surface morphology after debonding was observed using scanning electron microscopy (SEM). Results: Both water-air cooling and laser energy significantly affected the debonding time (P<0.0001). The trend of decreasing debonding time with increasing energy exhibited an "energy threshold": approximately 100 mJ for Group A and 200 mJ for Group B. Beyond these thresholds, further energy increase did not lead to a statistically significant reduction in debonding time. Furthermore, when parameters for both groups were set above their respective thresholds, no statistically significant difference in debonding time was observed (P>0.05). The temperature rise in the pulpal chamber of Group A was significantly higher than that of Group B. SEM observations revealed enamel exposure and damage on all tooth surfaces in Group A, whereas in Group B, only occasional pinpoint enamel exposure was observed at the 220 mJ level. Conclusion: Water-air spray cooling is a necessary safety measure for achieving safe and minimally invasive ceramic veneer removal with Er:YAG laser. For 0.5-mm lithium disilicate glass-ceramic veneers, it is recommended to employ continuous water-air cooling and set the laser energy near the identified threshold (200 mJ) to achieve an optimal "efficiency-safety" balance.

Key words: Er:YAG laser, water-air cooling, veneer, debonding

LI Xiaowen, XU Xinyi, XUE Miao, SUN Rui, SHENG Hanxing, BI Wenya, YAN Zhuoqun, SUN Lei. In Vitro Study on Effects of Water-air Cooling Mode and Laser Energy Parameters on Efficiency and Safety of Er:YAG Laser in Ceramic Veneer Removal[J]. Journal of Oral Science Research, 2026, 42(7): 591-595.

References

[1] Alghazzawi TF. Clinical survival rate and laboratory failure of dental veneers: A narrative literature review [J]. J Funct Biomater, 2024, 15(5): 131.
[2] Deeb JG, Grzech-Leśniak K, Brody ER, et al. Erbium laser-assisted ceramic debonding: a scoping review [J]. J Prosthodont, 2022, 31(9): e100-e124.
[3] Morford CK, Buu NC, Rechmann BM, et al. Er:YAG laser debonding of porcelain veneers [J]. Lasers Surg Med, 2011, 43(10): 965-974.
[4] Laky M, Toth P, Laky B, et al. Optimized erbium-doped yttrium aluminum garnet (Er:YAG) laser parameters for the removal of dental ceramic restorations [J]. Materials (Basel), 2023, 16(17): 5835.
[5] 洪燕如,江琦,朱建宇,等.铒激光拆除三种全瓷高嵌体的实验研究[J].口腔颌面修复学杂志,2024,25(2):103-108.
[6] El-Damanhoury HM, Salman B, Kheder W, et al. Er:YAG laser debonding of lithium disilicate laminate veneers: effect of laser power settings and veneer thickness on the debonding time and pulpal temperature [J]. J Lasers Med Sci, 2022, 13: e57.
[7] AlBalkhi M, Hamadah O. Influence of pulse duration and water/air cooling ratio on the efficiency of Er:YAG 2940 nm laser in debonding of porcelain laminate veneers: An in vitro study [J]. Clin Exp Dent Res, 2022, 8(4): 843-848.
[8] 庄娇玲,许志强,金地,等.Er-YAG激光对不同瓷贴面拆除效率的体外评价[J].上海口腔医学,2023,32(6):578-582.
[9] Jiang L, Li XY, Lu ZC, et al. Er:YAG laser settings for debonding zirconia restorations: An in vitro study [J]. J Mech Behav Biomed Mater, 2024, 151: 106331.
[10] ZACH L, COHEN G. PULP RESPONSE TO EXTERNALLY APPLIED HEAT [J]. Oral Surg Oral Med Oral Pathol, 1965, 19: 515-530.
[11] Gozneli R, Sendurur T. Er:YAG laser lithium disilicate crown removal: removal time and pulpal temperature change [J]. Lasers Med Sci, 2023, 38(1): 164.
[12] 李璐,申静,高静,等. Er:YAG激光在牙体硬组织疾病应用中对髓腔温度的影响[J]. 武汉大学学报(医学版),2023,44(7): 873-878.
[13] Alqutaibi AY, Saker S, Alghauli MA, et al. Clinical survival and complication rate of ceramic veneers bonded to different substrates: A systematic review and meta-analysis [J]. J Prosthet Dent, 2025,134(4): 1030-1039.
[14] Deeb JG, McCall C, Carrico CK, et al. Retrieval of prefabricated zirconia crowns with Er,Cr:YSGG laser from primary and permanent molars [J]. Materials (Basel), 2020, 13(23): 5569.
[15] Yilanci H, Yildirim ZB, Ramoglu SI. Intrapulpal temperature increase during Er:YAG laser-aided debonding of ceramic brackets [J]. Photomed Laser Surg, 2017, 35(4): 217-222.