A comparative analysis of dual-axis implants placed into maxillary anterior extraction sockets versus virtual planning with uniaxial implants: A simulated cone beam computed tomography study of implant length and diameter.

OBJECTIVE: The biaxial nature of the anterior maxilla poses a surgical and restorative challenge in implant dentistry. The present study sought to investigate the apical socket perforation rate (ASPR) from a simulated uniaxial implant placement and to determine the effect of implant length and diameter on ASPR when a uniaxial implant was placed compared with the orientation of the pre-existing dual-axis implant. MATERIAL AND METHOD: Cone beam computed tomography (CBCT) scans from the database of three private practices were searched for patients who received dual-axis implants within the esthetic zone in immediate tooth replacement therapy. A uniaxial implant was virtually placed using the pre-existing screw access channel of the dual-axis implant as a reference. The closest length and diameter were selected for the simulated implant. ASPR by the uniaxial implant was recorded. In addition, the affordable maximum length of a corresponding uniaxial implant that would avoid apical socket perforation was measured. RESULT: Eighty-one patients with a total of 101 dual-axis dental implants were selected for analysis. A simulated virtual surgical planning with uniaxial implants revealed high ASPR (48.51%). When the length of the uniaxial implant was reduced to 11 and 9 mm, ASPR was decreased to 41.58% and 20.79%, respectively. CONCLUSION: Dual-axis implant design effectively evades anatomical challenges in the anterior maxilla (esthetic zone). Considering the current evidence, efforts should be made to carefully consider the angular disparity between the extraction socket-alveolus complex and the future restorative emergence so that a harmonious biologic-esthetic result may be more predictably and consistently obtained.

Outcomes of a 1-Year Prospective Single-Arm Cohort Study Using a Novel Macro-Hybrid Implant Design in Extraction Sockets: Part 1.

A novel macro-hybrid implant design was introduced to afford high apical primary stability and more coronal space to preserve the circumferential extraction socket architecture. This study presents 1-year data from a prospective single-arm cohort study. The data was distilled based on the following criteria: (1) single-tooth immediate tooth replacement therapy (ITRT) in the maxillary anterior and premolar regions in intact (Type 1) extraction sockets that were (2) treated with the dual-zone grafting technique. The clinical and radiographic outcomes of 48 ITRT implants were evaluated. The mean ± SD labial plate dimension changes were 0.33 ± 0.41 mm at the implant abutment interface (L1) and 0.34 ± 0.40 mm at 5.0 mm below (L2). The mean labial plate dimension (thickness) at the 1-year recall was 2.27 ± 0.88 mm (L1) and 1.95 ± 0.95 mm (L2). At ITRT, the ridge contour at the free gingival margin and 3.0 mm below it were 7.54 ± 0.93 mm and 9.44 ± 2.36 mm, respectively; after final restoration delivery, the corresponding values were 7.45 ± 0.95 mm and 10.23 ± 2.30 mm, respectively. The peri-implant soft tissue thickness (PISTT) at the time of implant-level impression-making was 3.29 ± 0.73 mm, with an average Pink Esthetic Score of 12.79. A macro-hybrid implant design showed high levels of primary stability (~60 Ncm), stable ridge contour at 1 year, a labial plate dimension between 1.5 and 2.0 mm, and PISTT > 3.0 mm, which may be a critical factor in providing stable, long-term esthetic outcomes.

Use of a Novel Implant with an Inverted Body-Shift and Prosthetic Angle Correction Design for Immediate Tooth Replacement in the Esthetic Zone: A Clinical Case Series.

A clinical case series of three patients is presented using a novel implant design to not only address primary stability but also to prevent damage to the labial bone plate and improve the interdental space for papillae preservation with immediate tooth replacement therapy. This unique implant design features an apicocoronal inverted body-shift in diameter (wide to narrow), shape (tapered to cylindrical), thread depth (deep to shallow), and thread pattern (V-shaped to square) to achieve uncompromised primary stability and esthetics, particularly in extraction sockets, in a singular body form. In addition, the implant possesses a prosthetic angle correction within the implant body to facilitate screw-retention of the restoration and avoid the risk of apical socket perforation.

Complex Dental Implant Cases: Algorithms, Subjectivity, and Patient Cases Along the Complexity Continuum.

Algorithms for predictable outcomes, or checklists in health care, have been widely supported due to their highly effective outcomes. This article shares "algorithmic roadmaps" to restore single-tooth, partially edentulous, and fully edentulous complex dental implant cases in the patient population. A review of the current literature is presented to provide systematic assessments followed by criteria in a checklist format that allows the surgeon and restorative dentist to determine whether a removable or fixed implant prosthesis is the best patient option. Several cases have been chosen to illustrate the algorithms the authors used to provide an optimized prognosis for surgical/restorative success.

Angulated Implants for Fabrication of Implant Supported Fixed Partial Denture in the Maxilla.

Until recently, angled abutments have been the only solution to correcting the trajectory of the emergence profile of labially inclined implants in the maxilla. However, the clinical implications of angled abutments reveal several shortcomings. Newly designed angulated implants with a 12-degree restorative platform angulation are an alternative to angled abutments. The purpose of this article was to report a case utilizing new angulated implants (Co-axis, Keystone dental, Burlington, MA, USA) in the premaxilla thereby facilitating fabrication of a multi-unit implant retained fixed dental prosthesis.

Managing maxillary proclination with novel designed angulated implants.

Implant-supported removable dental prostheses may be supported by a variety of splinted (bar and clip) attachment systems or nonsplinted abutment-based attachments (ball, magnets, and resilient stud attachments such as locators [Zest Anchors], ERA [Sterngold], and nonresilient-stud attachments such as ANKYLOS SynCone [Dentsply Implants]). Nonsplinted attachments are preferred as they are more economical, less technique sensitive, easier to clean, repair, and maintain than splinted (bar and clip) attachment systems, but they work favorably only when implants in the arch are placed parallel to each other. Often implants in the anterior maxilla have to be placed with a labial inclination (due to the proclination of the premaxilla), resulting in lack of parallelism between the anterior and posterior implants, making it challenging to fabricate a removable dental prostheses supported by nonsplinted attachments, and necessitating the use of angled abutments. Recently, a novel implant design with a 12° restorative platform angulation has been introduced by Southern Implants (Co-axis, Keystone Dental, Inc., Burlington, MA, USA). These new angulated implants aid in minimizing the divergence between the anterior and posterior maxillary implants without using angled abutments. The purpose of this article was to report a case utilizing the novel angulated implants (Co-axis, Keystone Dental, Inc., Burlington, MA, USA) in the premaxilla for fabrication of maxillary removable dental prostheses supported and retained by nonsplinted attachments.

Accuracy and reliability of stitched cone-beam computed tomography images.

PURPOSE: This study was performed to evaluate the linear distance accuracy and reliability of stitched small field of view (FOV) cone-beam computed tomography (CBCT) reconstructed images for the fabrication of implant surgical guides. MATERIALS AND METHODS: Three gutta percha points were fixed on the inferior border of a cadaveric mandible to serve as control reference points. Ten additional gutta percha points, representing fiduciary markers, were scattered on the buccal and lingual cortices at the level of the proposed complete denture flange. A digital caliper was used to measure the distance between the reference points and fiduciary markers, which represented the anatomic linear dimension. The mandible was scanned using small FOV CBCT, and the images were then reconstructed and stitched using the manufacturer's imaging software. The same measurements were then taken with the CBCT software. RESULTS: The anatomic linear dimension measurements and stitched small FOV CBCT measurements were statistically evaluated for linear accuracy. The mean difference between the anatomic linear dimension measurements and the stitched small FOV CBCT measurements was found to be 0.34 mm with a 95% confidence interval of +0.24 - +0.44 mm and a mean standard deviation of 0.30 mm. The difference between the control and the stitched small FOV CBCT measurements was insignificant within the parameters defined by this study. CONCLUSION: The proven accuracy of stitched small FOV CBCT data sets may allow image-guided fabrication of implant surgical stents from such data sets.

Single tooth replacement utilizing implants in the esthetic zone: a case report.

Replacing a single tooth with an implant has become a common dental procedure; however, careful evaluation is necessary before placing one in the esthetic zone. Thorough diagnosis and planning - including the use of transposed diagnostic casts and cone beam computed tomography scans - can help dentists predict the final esthetic result prior to treatment, and help inform the patient of the potential result prior to performing any irreversible therapy. In the present case, the primary concern was the presurgical location of the facial free gingival margin (FGM) of the implant-supported crown, in relation to the adjacent teeth. Steps taken to correct the position of the facial FGM prior to implant placement led to a successful esthetic result.