One-Year Clinical Performance and Insertion Torque Pattern of a Contemporary Tapered Implant System: A Multicentre...

Primary stability, commonly quantified by insertion torque (ITV) and resonance frequency analysis (RFA/ISQ), is pivotal for predictable osseointegration and for making loading decisions with oral implants.

To report 1-year survival, stability, marginal bone level (MBL) changes, safety, and particularly the insertion torque characteristics of a contemporary tapered implant system (PrimeTaper EV, Dentsply Sirona Implants, Mölndal, Sweden).

This open-label, single-arm, multicentre investigation enrolled 138 subjects (intention-to-treat [ITT]; per-protocol [PP]=136) across five centres. Implants were placed according to the manufacturer's protocol. ITV (final and maximum) was recorded from machine-driven insertion; estimated peak manual torque was noted for manually placed implants. ISQ was measured at implant placement (IPV) and at permanent restoration (PR). Radiographic MBL was assessed at IPV, PR and PR+1 year. Descriptive statistics with 95% confidence intervals (CIs) were calculated. Survival at PR+1 year was compared to a performance goal of 89% using a one-sided binomial test (α=0.025). Torque curve data were processed in a dedicated technical analysis using normalized insertion time.

At PR+1 year, implant survival was 98.5% (PP, 134/136; 95% CI: 94.8 99.8%; p=0.000021 vs 89%) and 98.6% (ITT, 136/138; 95% CI: 94.9-99.8%; p=0.000017). For machine-driven placements (n=129), mean final ITV was 31.2±12.7 Ncm and mean maximum ITV 33.6±11.7 Ncm. Manual implant insertion occurred in 5.1% (7/136), yielding an estimated peak torque of 30.7±14.3 Ncm. Final manual seating with a torque wrench was performed in 15.5% (20/129) of the machine insertions, with a mean additional insertion depth of 1.5±0.8 mm. ISQ increased from 71.8±11.2 at IPV to 79.3±6.9 at PR (Δ+7.4; p<0.0001). The MBL change from PR to PR+1 year was -0.06±0.46 mm, and the cumulative change from IPV to PR+1 year was -0.16±0.51 mm. No serious adverse device effects (SADEs) were reported. Two implants were lost by the 1-year follow-up.

This implant design demonstrated high 1-year implant survival, minimal early crestal bone remodeling, and consistent torque profiles with mean final/peak torques of ~31/34 Ncm for machine insertions. Stability (ISQ) increased significantly by PR. Torque-curve analysis indicated continuous torque build-up throughout implant seating. Ongoing follow-up will clarify long-term performance. Scientific rationale: Primary implant stability is a key determinant for predictable osseointegration and loading protocols. The PrimeTaper EV implant features a conical, tapered design intended to enhance insertion torque and stability across varying bone qualities. However, prospective clinical data correlating intra-operative stability parameters with early clinical performance remain limited, justifying systematic evaluation of this implant design.

The PrimeTaper EV implant achieved primary stability values within common loading guidelines (~25-40 Ncm) while maintaining favourable hard tissue outcomes at 1 year.

By quantifying intra-operative insertion torque and early implant stability of the PrimeTaper EV system, this study provides clinically relevant reference values for daily practice. These data may assist clinicians in interpreting primary stability at placement and in making informed decisions regarding early clinical management.