This clinical study was conducted to evaluate the effect of different dental implant designs on implant stability and peri-implant bone levels during the early healing phase. Dental implants are widely used for the replacement of missing teeth, and their long-term success depends on achieving adequate primary stability and maintaining the surrounding bone. Variations in implant design, including thread configuration and body geometry, may influence the mechanical and biological behavior of implants, thereby affecting treatment outcomes.

The purpose of this study was to compare two different implant designs: double-threaded straight-body implants and triple-threaded conical-body implants. A total of 30 patients requiring implant-supported restorations in the posterior mandibular region were included in the study. Participants were randomly allocated into two groups, with each group receiving one type of implant design.

Implant stability was assessed using resonance frequency analysis (RFA), which provides implant stability quotient (ISQ) values as an objective measure of stability. In addition, peri-implant marginal bone levels were evaluated using standardized intraoral radiographs. These measurements were recorded at three time points: at the time of implant placement (baseline), at 3 months, and at 6 months after placement.

The primary objective of the study was to determine whether implant design influences implant stability over time. The secondary objective was to evaluate and compare marginal bone loss around the implants between the two groups during the early healing period.

The main research question addressed in this study was: Does the difference in implant thread design and body geometry significantly affect implant stability and peri-implant marginal bone loss during the early healing phase?

It was hypothesized that implants with a conical body design and multiple thread configuration may provide higher stability due to improved bone engagement and load distribution, while maintaining comparable bone levels around the implant.

The findings of this study are expected to provide clinically relevant evidence regarding the influence of implant macro-design on treatment outcomes. This may assist dental practitioners in selecting appropriate implant systems to enhance primary stability, promote successful osseointegration, and improve long-term prognosis in implant therapy.

Dental implants have become a widely accepted and predictable treatment modality for the rehabilitation of partially and completely edentulous patients. The long-term success of dental implants is primarily dependent on achieving and maintaining adequate implant stability and preserving peri-implant bone levels. Implant stability is influenced by several factors, including bone quality, surgical technique, and implant design. Among these, implant macro-design-particularly thread configuration and body geometry-plays a critical role in determining primary stability and stress distribution at the bone-implant interface.

Implant designs vary in terms of thread pitch, depth, and number of threads, as well as body shape (straight/cylindrical versus tapered/conical). Conical implants are believed to enhance primary stability by generating compressive forces within the surrounding bone, especially in areas of low bone density. Similarly, multiple-thread configurations may increase bone-to-implant contact and improve insertion efficiency and mechanical engagement. However, the combined influence of thread design and implant body geometry on implant stability and peri-implant bone behavior remains an area requiring further clinical investigation.

The present study was designed as a randomized, prospective interventional clinical trial with a parallel-group design to evaluate and compare implant stability and peri-implant marginal bone loss between two implant systems with different macro-design characteristics. A total of 30 patients requiring implant-supported restoration in the posterior mandibular region were included. Participants were randomly assigned into two groups using a computer-generated randomization method to ensure unbiased allocation.

Group A received double-threaded straight-body implants, while group B received triple-threaded conical-body implants. All implant placements were performed under standardized clinical conditions using a two-stage surgical protocol. Preoperative clinical and radiographic assessments were carried out to determine bone quality, quantity, and suitability for implant placement. Implant dimensions (diameter and length) were selected based on available bone at the implant site.

Primary implant stability was measured immediately after implant placement using resonance frequency analysis, which provides implant stability quotient values as an objective and non-invasive measure of stability. The same measurements were repeated at 3 months and 6 months postoperatively to evaluate changes in stability over time, reflecting the transition from primary mechanical stability to secondary biological stability during osseointegration.

Peri-implant marginal bone levels were assessed using standardized intraoral periapical radiographs obtained using a paralleling technique with grid calibration. Mesial and distal bone levels were measured relative to the implant platform at baseline, 3 months, and 6 months. These measurements were used to evaluate bone remodeling and marginal bone loss during the early healing phase.

All patients were followed up at regular intervals to monitor clinical healing, implant stability, and peri-implant tissue health. Postoperative care and follow-up protocols were standardized for all participants to minimize variability. Radiographic measurements were performed twice by the same examiner to ensure consistency, and intra-examiner reliability was evaluated.

The primary objective of the study was to compare implant stability between the two implant designs over time. The secondary objective was to evaluate and compare peri-implant marginal bone changes associated with each implant design during early healing.

The underlying hypothesis of the study was that triple-threaded conical-body implants would demonstrate superior implant stability due to enhanced mechanical engagement and compressive force distribution, while both implant designs would show comparable peri-implant bone response within clinically acceptable limits.

The results of this study are expected to contribute to the existing body of clinical evidence regarding the role of implant macro-design in influencing stability and bone preservation. This information may assist clinicians in selecting appropriate implant systems based on clinical requirements, thereby improving treatment outcomes and long-term success in implant dentistry.

Inclusion criteria:

• Patients aged 18 years and above
• Patients with missing mandibular premolars or molars requiring implant-supported restoration
• Presence of adequate bone volume and density at the implant site for proper implant placement
• Patients with good general health and no systemic conditions affecting healing
• Patients maintaining satisfactory oral hygiene
• Patients who are cooperative and able to understand the treatment procedure
• Patients willing to undergo implant surgery and attend follow-up visits
• Patients who provide written informed consent

Exclusion criteria:

• Patients with active infection or pathology at the implant site
• Patients with insufficient bone quality or volume for implant placement
• Patients with systemic diseases or conditions that may impair healing
• Patients with a history of bleeding disorders or on anticoagulant therapy
• Immunocompromised or medically compromised patients
• Patients with poor oral hygiene or non-compliance
• Pregnant or lactating women
• Patients unwilling to participate or unable to provide informed consent

De-identified individual participant data, including demographic details (age, sex), implant characteristics (type, size), implant stability quotient values recorded at baseline, 3 months, and 6 months, and peri-implant marginal bone measurements (mesial and distal bone levels and calculated bone loss) at corresponding time points, will be shared.

Data will be available starting 6 months after publication of the study and will remain available for a period of 5 years.

Access to de-identified individual participant data (IPD) and supporting documents will be provided to qualified researchers who submit a methodologically sound research proposal. Researchers will be required to state the study's purpose and demonstrate its scientific validity. Data will be limited to variables necessary to achieve the approved research objectives, including implant stability (ISQ values) and peri-implant bone measurements.

Requests should be directed to the corresponding author, and access will be granted upon review and approval of the proposal. Data and supporting documents will be shared via email or a secure data-sharing platform, in compliance with institutional ethical guidelines and patient confidentiality requirements.

In this study, the examiner responsible for radiographic measurements and statistical analysis was blinded to the group allocation to minimize measurement and assessment bias. Due to the nature of the surgical procedure and differences in implant design, blinding of participants and care providers was not feasible.