Less Invasive Surgical Procedures Using Narrow-Diameter Implants: A Prospective Study in 20 Consecutive Patients

Abstract

Narrow-diameter implants (NDIs) are increasingly produced and used in implant dentistry, especially since the introduction of new, more resistant materials. The objective of the present study was to evaluate the clinical performance of NDIs (3.3 mm) placed in thin alveolar crests. Twenty consecutive patients needing implant-supported fixed partial dentures and presenting an alveolar thickness ≤6 mm were treated with 1 or several NDIs. The surgical protocol was chosen according to the clinical situation: (1) flapless, (2) mini-cervical flap, (3) wide flap, (4) wide flap + guided bone regeneration (GBR). Implants were immediately loaded if the primary stability was higher than 20 Ncm. Implant survival and success, prosthodontic success rates, and patient-centered outcomes were evaluated after a follow-up period of 1 year. A total of 39 implants were placed in 20 patients, 12 and 27 implants in the anterior regions and in the posterior mandible, respectively. All but 1 implant reached an insertion torque higher than 20 Ncm and were loaded within 48 hours. The implant survival and success rates both reached 94.7%. The need for GBR was avoided in 60% of the implant sites. The mean peri-implant bone remodeling after a follow-up period of 1 year was −0.35 mm at the implant level. Peri-implant bone remodeling was higher in the posterior region, when the alveolar crest was thinner than 4 mm and GBR was required in addition. In conclusion, use of NDIs to restore partial edentation in sites with limited horizontal thickness seems to be an effective treatment option that prevented GBR in the majority of the present cases. Immediate provisionalization of NDIs does not seem to impair the results.

Fatigue Failure of Narrow Implants with Different Implant‐Abutment Connection Designs

“…Clinically, the survival rates of NDIs are encouraging (94.7% to 97.25%) and comparable to standard‐diameter implants. Fatigue and clinical studies are still necessary to characterize and provide guidelines to clinicians for the multitude of variables that can be incorporated in the restoration process of NDIs, such as implant bulk material, retention method (screwed vs. cemented), single versus multiple units, and many others that have been already reported for standard diameter implants.…”

Narrow‐diameter implants: A systematic review and meta‐analysis

“…However, there were several studies showing promising results for NDI of Category 3 for the posterior jaw. A recent review on the clinical performance of narrow‐diameter titanium–zirconium implants (TiZr) indicated that these implants could be reliable for restorations in the posterior region, even when replacing single missing molars (Badran et al., ; F. E. Lambert et al., ; Tolentino et al., ). However, long‐term data are rare so far.…”

Narrow‐ (3.0 mm) Versus Standard‐Diameter (4.0 and 4.5 mm) Implants for Splinted Partial Fixed Restoration of Posterior Mandibular and Maxillary Jaws: A 5‐Year Retrospective Cohort Study

“…Bone availability in the edentulous ridge determines implant dimensions, and NDIs may represent a minimally invasive treatment alternative for the rehabilitation of narrow posterior ridges (≤5.5 mm), 16 , 23 , 24 which would require a bone augmentation surgery before placement of SDIs. However, caution has been suggested in the use of NDIs in posterior areas with high occlusal loading due to risk of fatigue fracture of titanium implants, as reported in some studies 25–27 .…”

“…This result seems to contradict findings of previous experimental studies using finite element analyses, in which implant diameter reduction was associated with a greater stress and strain concentration around the head of the implants 14 , 31 . The non‐significant between‐group difference in marginal bone loss suggests that splinting multiple NDIs could protect against generating excessive stress and resorption in the marginal peri‐implant bone 24 , 32 , 33 . Romeo et al 28 found similar mean MBL values for NDIs and SDIs in a partially dentate population, with a significant tendency toward increased mean bone loss passing from start of loading and the latest examination after 1 to 7 years.…”