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Statement of problemIn patients with an altered skeletal maxillomandibular relationship and bone resorption, the rehabilitation of edentulous jaws by combining 4 implants, 2 straight medially and 2 tilted distally, may be preferred to avoid a bone augmentation procedure.PurposeThe purpose of this single cohort 1-year prospective study was to evaluate the clinical performance of a 4-implant overdenture fully supported by a computer-aided designed and computer-aided manufactured (CAD-CAM) titanium bar.Material and methodsThis single cohort prospective study included edentulous participants rehabilitated with a 4-implant overdenture in 1 of the 2 jaws. The outcomes were implant and prosthetic survival and success rates, any biologic and technical complications, periimplant marginal bone loss, changes in the oral health impact profile (OHIP), bleeding on probing, and the plaque index.ResultsEighteen participants received 72 implants. One year after implant placement, no implants or prosthesis had failed, and no biologic or technical complications had been observed. At the 1-year follow-up, the mean marginal bone loss was 0.29 ±0.16 mm. The OHIP summary scores demonstrated a significant improvement in oral health-related quality of life. At the 1-year follow-up, positive bleeding was found in 2 participants (11.1%) around 3 implants (4.1%). Three participants (16.6%), accounting for 5 implants (6.9%), showed a slight amount of plaque.ConclusionsA 4-implant overdenture supported by a CAD-CAM titanium bar may be a reliable option for the treatment of the edentulous mandible and maxilla over a 1-year period. Oral health-related quality of life significantly improved in all treated participants.

PurposeThe study aims to evaluate clinically the thickness of the alveolar ridge mucosa underneath a zirconia implant-supported restoration with a modified ovate pontic.Materials and methodsSixty-five patients, 32 women and 33 men (mean age: 65.5 years; range 38-81), were included. A total of 383 implants (303 in the maxilla; 80 in the mandible), supporting 81 full or partial fixed dental prostheses (65 in the maxilla; 16 in the mandible), were either cement- or screw-retained. Three years after loading, a total of 219 pontic sites (153 in the maxilla; 66 in the mandible) were measured, and the thickness of the alveolar ridge mucosa between the prosthetic surface and the underlying bone crest were recorded.ResultsThe overall implant and prosthesis survival rates at 3 years were 98.7% and 100%, respectively. No implant complications were reported, scoring a cumulative implant success rate of 100%. In the maxilla, the overall mean thickness of the alveolar ridge mucosa was 2.32 ± 0.57 mm. In the mandible, the overall mean thickness of the alveolar ridge mucosa was 2.20 ± 0.62 mm. There was no statistical difference between the overall mean values in the maxilla and mandible (p = .471).ConclusionThis radiologic retrospective study suggests the existence of a physiological barrier, named prosthetic biological width, underneath a novel pontic-designed restoration.

PurposeThe study aims to evaluate clinically the thickness of the alveolar ridge mucosa underneath a zirconia implant-supported restoration with a modified ovate pontic.Materials and methodsSixty-five patients, 32 women and 33 men (mean age: 65.5 years; range 38-81), were included. A total of 383 implants (303 in the maxilla; 80 in the mandible), supporting 81 full or partial fixed dental prostheses (65 in the maxilla; 16 in the mandible), were either cement- or screw-retained. Three years after loading, a total of 219 pontic sites (153 in the maxilla; 66 in the mandible) were measured, and the thickness of the alveolar ridge mucosa between the prosthetic surface and the underlying bone crest were recorded.ResultsThe overall implant and prosthesis survival rates at 3 years were 98.7% and 100%, respectively. No implant complications were reported, scoring a cumulative implant success rate of 100%. In the maxilla, the overall mean thickness of the alveolar ridge mucosa was 2.32 ± 0.57 mm. In the mandible, the overall mean thickness of the alveolar ridge mucosa was 2.20 ± 0.62 mm. There was no statistical difference between the overall mean values in the maxilla and mandible (p = .471).ConclusionThis radiologic retrospective study suggests the existence of a physiological barrier, named prosthetic biological width, underneath a novel pontic-designed restoration.

PurposeTo evaluate the clinical and radiological performance of an immediately loaded novel implant design over a 3-year period.Materials and methodsThis prospective study includes 54 consecutive partially edentulous patients treated between December 2010 and October 2011. Outcome measures were: implant and prosthetic failures; biological and mechanical complications; marginal bone loss (MBL); sulcus bleeding index (SBI); and plaque score (PS).ResultsA total of 118 (29 narrow platform, 70 regular platform and 19 wide platform) NobelReplace Conical Connection implants were placed in both post-extraction sockets and healed sites and immediately loaded. The mean insertion torque was 63.4 ± 7.1 Ncm. One hundred out of 118 implants (84.7%) were inserted with a torque ranging between 55 and 70 Ncm. Each patient received a single prosthesis. At the 3-year follow-up, no patient dropped out and only two post-extractive implants failed (1.7%) in two patients (3.7%). The only complication (1.9%) observed was an event of periimplantitis, consisting of a mean mesiodistal peri-implant bone loss of 3.2 mm reported in a healed site of a smoker patient at the 2-year follow-up examination. No prosthesis failures were detected. The cumulative mean MBL between implant placements at the 3-year follow-up was 0.68 mm (95% CI: 0.44, 0.92). At the 3-year follow-up session, the SBI and PS were 5.7% and 15.4%, respectively.ConclusionsThe NobelReplace Conical Connection implant can be considered as a valuable treatment option for immediate implant placement and loading in the partially edentulous patients over a 3-year period. Insertion torques ranging between 55 and 70 Ncm are not detrimental to osseointegration.

PurposeTo compare the clinical and radiological outcomes of two implant designs with different prosthetic interfaces and neck configurations.Materials and methodsThirty-four partially edentate patients randomly received at least one NobelActive implant (Nobel Biocare, Göteborg, Sweden) with back-tapered collar, internal conical connection and platform shifting design, and one NobelSpeedy implant (Nobel Biocare) with external hexagon and flat-to-flat implant-abutment interface according to a split-mouth design. Follow-up continued to 3 years post-loading. The primary outcome measures were the success rates of the implants and prostheses, and the occurrence of any surgical and prosthetic complications during the entire follow-up. Secondary outcome measures were: horizontal and vertical peri-implant marginal bone level (MBL) changes, resonance frequency analysis values at implant placement and loading (4 months), sulcus bleeding index (SBI) and plaque score (PS).ResultsNo drop-out occurred. No implants and prostheses failures were observed to the 3-year follow-up. MBL changes were statistically significant different with better results for the NobelActive implants for both horizontal and vertical measurements (P = 0.000). After 3 years post-loading, the NobelActive implants underwent a mean vertical bone resorption of 0.66 mm, compared with 1.25 mm for the NobelSpeedy Groovy implants (P = 0.000); the mean horizontal bone resorption was 0.19 mm for the NobelActive implants and 0.60 mm for the NobelSpeedy Groovy implants (P = 0.000). A high ISQ value was found for both implants, and no statistically significant difference was found for ISQ mean values between interventions (P = 0.941 at baseline; P = 0.454 at implantabutment connection; P = 0.120 at prosthesis delivery). All implants showed good periodontal health at the 3-year-in-function visit, with no significant differences between groups.ConclusionThe results of this research suggest that in well-maintained patients, the MBL changes could be affected by the different implant design. After 4 months of unloaded healing, as well as after 3 years in function, both implants provided good results, however vertical and horizontal bone loss had statistically significant differences between the two groups (difference of 0.58 ± 0.10 mm for the vertical MBL, and 0.4 ± 0.05 mm for the horizontal MBL), with lower values in the Nobel Active implants, compared to the NobelSpeedy Groovy implants.