This randomized controlled clinical trial aims to evaluate the effect of different biological drilling speeds (50, 150, and 300 rpm) during implant osteotomy preparation in the mandible on marginal bone level changes and implant stability. Thirty-nine patients requiring a single dental implant in the mandible will be randomly allocated into three groups according to drilling speed. All implants will be placed using a biological drilling protocol without irrigation. Implant stability will be measured using resonance frequency analysis at implant placement and follow-up visits. Marginal bone levels will be evaluated radiographically using standardized periapical radiographs during the follow-up period up to 12 months. The study aims to determine whether different low-speed drilling protocols influence peri-implant bone remodeling and implant stability.

This randomized parallel-group clinical trial will investigate the influence of different biological drilling speeds on radiographic marginal bone level changes and implant stability in mandibular dental implant placement.

Thirty-nine partially edentulous adult patients requiring a single implant in the mandible will be recruited from the outpatient clinic of the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Cairo University. Eligible participants will be randomly assigned to one of three groups according to drilling speed used during osteotomy preparation: 50 rpm, 150 rpm, or 300 rpm.

Implant site preparation will be performed using the same sequential drilling protocol and implant system in all groups. Biological drilling will be performed without irrigation, with careful control of drilling pressure and intermittent drilling to minimize thermal trauma.

Implant stability will be measured using resonance frequency analysis (RFA) at implant placement and during follow-up visits. Radiographic assessment of marginal bone levels will be conducted using standardized periapical radiographs obtained using the paralleling technique. Radiographic measurements will be performed at baseline and during follow-up visits up to 12 months.

The primary outcome of the study will be marginal bone level changes measured radiographically in millimeters. The secondary outcome will be implant stability expressed as Implant Stability Quotient (ISQ) values.

The results of this study may help identify the optimal biological drilling speed that preserves bone vitality while maintaining adequate implant stability and favorable peri-implant bone remodeling.

Inclusion Criteria:

• Adult patients aged 20-60 years.
• Partially edentulous patients requiring a single dental implant in the mandible.
• Adequate bone height and width at the implant site to accommodate the planned implant dimensions without the need for advanced grafting.
• Good oral hygiene (full-mouth plaque and bleeding scores within acceptable limits).
• Patients willing to participate, available for 12-month follow-up, and able to sign informed consent.

Exclusion Criteria:

• Systemic diseases or conditions that may compromise bone healing (e.g. uncontrolled diabetes, immunosuppression, recent radiotherapy in head and neck region).
• Smoking more than 10 cigarettes/day or heavy vaping.
• Pregnant or lactating women.
• History of bisphosphonate or other anti-resorptive therapy affecting bone metabolism.
• Active periodontal disease or poor oral hygiene.
• Acute infection or pathology at the planned implant site.
• Need for simultaneous major bone grafting at the same site.
• Bruxism or severe parafunctional habits.

Outcome assessors evaluating radiographic marginal bone levels and implant stability measurements will be blinded to group allocation. The surgeon cannot be blinded due to the nature of the intervention.