Background/Aim. Low-level laser therapy (LLLT) has been proven to stimulate bone repair, affecting cellular proliferation, differentiation and adhesion, and has shown a potential to reduce the healing time following implant placement. The aim of this clinical study was to investigate the influence of postoperative LLLT osseointegration and early success of self-tapping implants placed into low-density bone. Methods. Following the split-mouth design, self-tapping implants (n = 44) were inserted in the posterior maxilla of 12 patients. One jaw side randomly received LLLT (test group), while the other side was placebo (control group). For LLLT, a 637 nm gallium-aluminum-arsenide (GaAlAs) laser (Medicolaser 637, Technoline, Belgrade, Serbia) with an output power of 40 mW and continuous wave was used. Low-level laser treatment was performed immediately after the surgery and then repeated every day in the following 7 days. The total irradiation dose per treatment was 6.26 J/cm? per implant. The study outcomes were: implant stability, alkaline-phosphatase (ALP) activity and early implant success rate. The follow-up took 6 weeks. Results. Irradiated implants achieved a higher stability compared with controls during the entire follow-up and the difference reached significance in the 5th postoperative week (paired t-test, p = 0.030). The difference in ALP activity between the groups was insignificant in any observation point (paired t-test, p > 0.05). The early implant success rate was 100%, regardless of LLLT usage. Conclusion. LLLT applied daily during the first postoperative week expressed no significant influence on the osseointegration of selftapping implants placed into low density bone of the posterior maxilla. Placement of self-tapping macro-designed implants into low density bone could be a predictable therapeutic procedure with a high early success rate regardless of LLLT usage.

Background: The data on polyetheretherketone (PEEK) influence on the peri-implant soft tissues in clinical settings are deficient. The aims of this pilot study were to analyze and compare soft tissues’ response to PEEK and titanium (Ti) healing abutments (HA) by means of histological and immunohistochemical analyses.Methods: A total of 22 implants with PEEK or Ti HA were placed in 11 patients, applying the “split-mouth” study design. Three months later, soft tissue specimens were harvested from 20 implants for histology in order to qualitatively detect the inflammatory cells’ presence, to semi-qualitatively analyze the inflammation intensity and to assess the inflammatory responses type by immunohistochemical analysis using LCA, CD3, CD20 and CD68 antibodies.Results: Epithelial infiltrate followed by an intensive inflammation in sub-epithelium was observed in 100% around PEEK HA. A number of LCA+ and CD 68+ cells was significantly higher in PEEK comparing to Ti group (p = 0.001 andp = 0.020, respectively), while CD 20+ and CD3+ counted cells were found in a significantly higher amount in Ti than in PEEK group (p = 0.006 andp = 0.010, respectively).Conclusion: PEEK HA seems to evoke the more intense tissue inflammatory response demonstrated predominantly by histocytes’ and plasmacytes’ activation, while Ti HA triggers the inflammatory reaction of lower intensity, dominantly mediated by B-cells.Trial registration: The study registered atClinicalTrials.gov(NCT04436939).