Purpose: To compare osteocalcin and crestal bone loss in implants placed under an immediate loading (IL) compared to a delayed loading (DL) protocol.
Materials and Methods: This preliminary, split-mouth, randomized controlled trial included 14 participants who required replacement of both mandibular first molars opposing a completely dentate maxillary arch. Two implants were placed in each participant. According to the split-mouth randomization method, a temporary crown was used for the IL protocol and a healing abutment was used for the DL protocol in each participant. Definitive crowns were cemented 3 months after implant placement. Osteocalcin levels were determined using ELISA, and crestal bone loss was evaluated using radiographs at 2 weeks, 3 months, and 12 months after implant placement.
Results: The mean osteocalcin level was significantly higher with IL than DL at each point (P < .001), with 95% CI of –262.89 to –439.10 (2 weeks); –238.02 to –375.98 (3 months); and –83.24 to –211.61 (12 months). Higher crestal bone loss was observed in IL when compared to DL implants at 2 weeks (P = .458, 95% CI: –0.10 to 0.21). Less crestal bone loss was observed with IL than DL at 3 months (P = .935) and 12 months (P = .42).
Conclusion: Osteocalcin levels increased in both IL and DL implants, but higher levels were observed with IL. Higher crestal bone loss was observed with IL during the initial stages of treatment only.