Rehabilitation of Atrophic Mandible with Ultrashort Implants Combined with Photobiomodulation Therapy: A Split-Mouth Design Study

BACKGROUND: Atrophic edentulous mandible is a challenging clinical condition. Studies assessing the use of ultrashort implants to support overdentures are scarce; the optimum photobiomodulation (PBM) dose for enhancing osseointegration is yet unknown. OBJECTIVE: This study aimed to evaluate and compare mandibular overdentures assisted by two versus four ultrashort implants with adjunctive PBM therapy using two doses. MATERIALS AND METHODS: A total of 36 implants were placed in 12 edentulous male participants and they were randomly allocated to Group I (mandibular overdentures assisted by two ultrashort implants) or Group II (by four ultrashort implants). Fully guided implant placement was performed, and then a split-mouth design was implemented. The participants received PBM by diode laser (660 nm). Dose A (3.75 J/cm(2)) and Dose B (7.5 J/cm(2)) were applied to the right and left implant (s), respectively. Implant stability, peri-implant probing depth (PIPD), and modified gingival index (MGI) were evaluated at baseline, and at 6 and 12 months after loading. RESULTS: After 12 months, the implant stability values were significantly higher in Group II compared with Group I (P < 0.001). A significant difference was observed in between the PIPDs of both groups (Group I: 2.35 ± 0.54 mm; Group II: 1.69 ± 0.35 mm;P= 0.001). The mean MGI values were low for both groups (Group I: 0.75 ± 0.58; Group II: 0.51 ± 0.41). CONCLUSIONS: Mandibular overdentures supported by four ultrashort implants had a more favorable clinical outcome, while PBM doses A and B were comparable in all evaluated parameters. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03540316.