Tissue-Level Laser-Lok Implants Placed with a Flapless Technique: A 4-Year Clinical Study

Background: The present study aims to analyze the use of Laser-Lok microtextured neck implants placed with a transmucosal surgical approach. The marginal bone level (MBL) and periodontal parameters were evaluated in a cohort prospective 4-year clinical study. Methods: A total of 41 implants were placed in 36 healthy consecutive patients (16 males, 20 females, mean age 60 ± 9 years). Tapered tissue level implants, characterized by a 2.0 mm laser-microtextured neck, were used with a flapless approach. Customized abutments and provisional resin crowns were positioned. Definitive metal-ceramic crowns were cemented approximately 4 months after insertion. Periapical radiographs were taken after 1, 3, 6, 12, 36 and 48 months from implant placement to evaluate MBL. Gingival thickness (thin/thick), plaque score (PS) and bleeding on probing (BoP) were evaluated. Results: After 48 months, all implants were safe from complications. No complications, peri-implantitis, early implant failures or mucositis occurred. The survival rate was 100%. Mean MBL during the follow-up was -0.15 ± 0.18 at T1, -0.29 ± 0.29 at T3, -0.45 ± 0.37 at T6, -0.53 ± 0.45 at T12, -1.06 ± 1.13 at T 36 and -1.10 ± 0.89 at T 48. Implants placed 2-3 months after tooth extraction revealed lower MBL variation when compared to those placed immediately (in fresh extraction sockets) or in completely healed ridges (delayed group). Narrower diameter implants (3.8 mm) showed significantly higher MBL variation when compared to 4.6 diameter implants. Multilevel analysis at T48 revealed that among all the evaluated variables, implant diameter was the factor mostly associated with MBL modifications (p = 0.027). Conclusion: This 4-year clinical study supports the use of Laser-Lok implants placed at tissue level with a flapless approach. A limited bone loss during the 48-month follow-up was observed. Periodontal parameters were stable with no sign of inflammation or soft tissue alteration. The use of Laser-Lok implants with transmucosal surgery represents a suitable technique with a minimally invasive approach.