Maxillary implant overdentures retained with bars or solitary attachments: A 5-year randomised controlled trial.

Purpose To compare the 5-year follow-up outcomes of maxillary overdentures retained by bars or solitary attachments.Methods Fifty consecutively selected fully edentulous patients experiencing problems with their conventional denture received four implants and were randomly allocated to receive a maxillary overdenture with either bar- or solitary attachment retention. Marginal bone level change (primary outcome), implant- and overdenture survival rate, clinical- and patient related outcome measures were recorded at baseline, and after 1 and 5 years. Biological and technical complications were recorded throughout the entire follow-up period.Results After 5 years, the mean marginal bone level change was higher in the solitary attachment group (-1.41±1.38mm, P=0.024) than in the bar group (-0.99±0.96mm). Also, fewer implants survived in the solitary attachment group (89.5%, P=0.027) than in the bar group (96.3%). The overdenture survival rate was 95.0% and 91.3% in the bar and solitary attachment group, respectively. Although the clinical and patient related outcomes were favourable and did not differ significantly between the groups, the peri-implantitis incidence was 25.8% in the solitary attachment group and 5.1% in the bar group. Any technical complications were minor.Conclusions In maxillary 4-implant overdenture therapy, the marginal bone level, implant survival rate and the number of complications are better with bar attachments than with solitary attachments. Both groups' clinical and patient related outcome measure scores were equal throughout the entire follow-up period.

Bone Level Tapered Implants in the Maxillary Esthetic Zone: A 1-Year Prospective Case Series in Healed Sites.

PURPOSE: Bone level tapered implants have an advantage in terms of stability and less need for additional bone augmentation procedures in healed sites, which might be advantageous for the esthetic zone. The aim of this study was to assess the clinical, radiographic, and esthetic performance of bone level tapered implants placed in healed sites in the maxillary esthetic region during a 1-year evaluation period. MATERIALS AND METHODS: Thirty participants (15 male, 15 female) with a single-tooth diastema that had healed without an alveolar ridge preservation procedure received a bone level tapered implant. Buccal bone augmentation procedures were performed at implant placement if the labial bone wall thickness was < 2 mm. A provisional crown was connected after a healing phase of 3 months. A definitive crown was placed 3 months after the provisional restoration. Implant stability, peri-implant soft and hard tissue health, esthetics, and patient-reported outcomes were recorded. RESULTS: All the placed implants demonstrated good stability. A labial bone augmentation technique was needed in 23 of the 30 cases. The median implant stability quotient value was 73 (68;76) at implant placement and had increased to 79 (76;81) when the definitive restoration was inserted (P < .005). All patients were present at the 1-year evaluation, and none had lost an implant. The mean loss of marginal bone was 0.07 ± 0.10 mm. The midbuccal mucosa-level recession was 0.14 ± 0.40 mm. There was an overall gain in papilla height: +0.05 ± 0.60 mm mesially and +0.06 ± 0.53 mm distally. Median values of the pink esthetic score and white esthetic score were 6 (4;7 interquartile range) and 8 (7;8.3 interquartile range), respectively. The participants' mean overall satisfaction was 90.1 ± 6.5 on a visual analog scale. No complications occurred. CONCLUSION: It can be concluded from a 1-year followup that treatment with the bone level tapered implant system resulted in good implant stability, healthy peri-implant soft and hard tissues, satisfying esthetics, and good patient-reported outcomes.

Implant-Supported Three-Unit Fixed Dental Prosthesis Using Coded Healing Abutments and Fabricated Using a Digital Workflow: A 1-Year Prospective Case Series Study.

PURPOSE: To test the applicability of coded healing abutments, intraoral scanners, and monolithic zirconia for the fabrication of three-unit fixed dental prostheses (FDPs) on two dental implants. MATERIALS AND METHODS: Patients with three missing teeth in the posterior region of either the maxilla or mandible received two dental implants. After healing, coded healing abutments were placed. Full-arch intraoral scans were made to produce individual titanium abutments and a three-unit FDP. Peri-implant tissues were assessed 2 weeks after placement of the FDP and again after 1 year. Patient-reported outcome measures were registered prior to treatment and after 1 year. The quality of the FDPs was assessed using modified United States Public Health Service criteria after 1 year of service. RESULTS: A total of 54 patients were treated with 60 restorations, and 51 patients with 56 restorations were available at the 1-year follow-up. Implant survival was 99.1%, and prosthesis survival was 100%. The peri-implant tissues remained healthy, and patient satisfaction was high. However, the USPHS evaluation showed that some prostheses exhibited fit or color issues that needed to be addressed, although most were rated as successful (80.4%). CONCLUSION: The use of coded healing abutments and intraoral scanners to produce full-zirconia three-unit FDPs on two dental implants proved to be a feasible technique, with promising objective and subjective results. However, technical challenges still impacted the treatment results, resulting in a number of restorations having clinical or radiographic marginal gaps or reduced color match.

Influence of Cervical Crown Contour on Marginal Bone Loss Around Platform-Switched Bone-Level Implants: A 5-Year Cross-Sectional Study.

PURPOSE: To evaluate the influence of the cervical crown contour on marginal bone loss and soft tissue health around platform-switched, posteriorly placed, two-piece implants. MATERIALS AND METHODS: A dataset from two previously conducted studies was used. Patients with single two-piece, platform-switched implants in between two natural teeth or adjacent to one natural tooth were included. Clinical parameters and standardized periapical radiographs from 1 month and 5 years after final crown placement were assessed. A new measurement method was developed to analyze geometric values of the cervical crown contour. Inter- and intraexaminer reliability were assessed. Emergence angles were measured at 1, 2, and 3 mm above the implant shoulder. Linear correlations between variables were determined by calculating Pearson correlation coefficients. RESULTS: A total of 64 patients with 67 posterior implants met the inclusion criteria. At 1, 2, and 3 mm above the implant shoulder, mean emergence angles at the mesial implant sites were 0.5 ± 2.8, 12.8 ± 12.8, and 18.0 ± 11.3 degrees, respectively. At the distal sites, the corresponding values were 2.8 ± 8.3, 16.2 ±16.6, and 18.7 ± 13.8 degrees, respectively. Mean marginal bone loss between 1 month and the 5-year evaluations was 0.14 ± 0.34 mm at the mesial aspect and 0.26 ± 0.47 at the distal aspect of implants. No correlation with peri-implant bone loss or soft tissue health could be found. No implants showed signs of peri-implantitis. CONCLUSION: The cervical crown contour at platform-switched, posteriorly placed, two-piece implants showed no correlation with peri-implant marginal bone loss or soft tissue health up to 5 years after implant placement.

Outcome of Treatment with Single Implants in Preserved Versus Nonpreserved Alveolar Ridges: A 1-year Cohort Study.

PURPOSE: To evaluate the effect of placement of single implants in the esthetic zone of the maxilla in preserved alveolar ridges, compared with nonpreserved alveolar ridges, on the change in midlabial mucosal level, esthetics, marginal bone level, and patient satisfaction. MATERIALS AND METHODS: Patients with a failing single tooth, and demonstrating a large vertical defect (≥ 5 mm) of the labial wall of the extraction socket, were pre-augmented with a mixture of autologous bone and anorganic bovine bone. A mucosal graft sealed the pocket. After 4 months, a single implant was placed in the preserved alveolar ridge (test group; n = 20). The results were compared with those from patients who had one missing tooth and were treated with placement of an implant in a nonpreserved alveolar ridge, whereby the connective tissue graft was combined with the placement of the implant (control group; n = 20). Changes in midlabial mucosal level were scored on intraoral images. Intraoral radiographs were made to assess marginal bone level changes after definitive crown placement (1 month [T1], 12 [T12] months). The pink esthetic score/white esthetic score at T12 was used to determine esthetics. Patient satisfaction was assessed before treatment (Tpre), and at T1 and T12. RESULTS: The mean midlabial mucosal level changes were 0.07 ± 0.29 mm and -0.15 ± 0.23 mm at T1 and T12 for the control and test groups, respectively (P = .01). No significant changes were observed for the other outcome variables. CONCLUSION: Single implant treatment in a preserved alveolar ridge and nonpreserved alveolar ridge is accompanied by clinically nonrelevant changes in the midlabial mucosal level. Changes in marginal bone level, esthetics, and patient satisfaction were comparable between the groups.

Osseointegration of a Zirconia Implant: A Histologic Assessment.

PURPOSE: The aim of this study was to describe the histologic and histomorphometric features of a retrieved, functional endosseous zirconia implant in a human subject. MATERIALS AND METHODS: A maxillary zirconia implant (ZV3) placed in a 52-year-old man was retrieved after 2 years of uncompromised service and prepared for light microscopic evaluation. RESULTS: Histologic examination demonstrated good osseointegration. Bone contact measurements revealed a mean percentage of bone-to-implant contact of 55.8% (SD 3.8%). CONCLUSION: The histologic data provide further evidence of the potential of zirconia implants to osseointegrate to a similar degree as titanium in humans.

Immediate Loading of Anterior Single-Tooth Implants Placed in Healed Sites: Five-Year Results of a Randomized Clinical Trial.

PURPOSE: The aim of this study was to compare the 5-year outcome of immediate loading with that of conventional loading for anterior single-tooth implants placed in healed sites. It was hypothesized that immediate loading is not inferior to conventional loading. MATERIALS AND METHODS: A total of 62 patients with a missing maxillary anterior tooth were included. At random, patients were treated with an implant that was restored either with a nonoccluding temporary crown within 24 hours after implant placement (immediate group) or according to a two-stage procedure after 3 months (conventional group). All implants were placed in healed sites. Follow-up visits were performed after definitive crown delivery and 1 and 5 years thereafter. Outcome measures were radiographic marginal bone level changes, implant survival, complications, soft tissue aspects (probing depth, plaque, bleeding, soft tissue level changes), esthetic outcome, and patient satisfaction. RESULTS: Three patients in each study group were lost to follow-up. No significant differences were found in terms of marginal bone loss (1.16 ± 0.93 mm in the immediate group and 1.20 ± 1.10 mm in the conventional group), survival (one implant lost in the immediate group), complications, soft tissue aspects, esthetic outcome, and patient satisfaction. CONCLUSION: For anterior single-tooth implants placed in healed sites, the outcome of immediate loading is not inferior to conventional loading.

Impact of Crown-Implant Ratio of Single Restorations Supported by 6-mm Implants: A Short-Term Case Series Study.

PURPOSE: High crown-implant ratios might affect the biologic and technical performance of a reconstruction. The aim of this study was to assess whether a higher crown-implant ratio of single restorations on 6-mm implants resulted in more peri-implant bone loss and more prosthetic complications during a 1-year followup period. MATERIALS AND METHODS: A group of 37 patients were provided with 47 single-implant-supported restorations on 6-mm implants. Implants were placed in the posterior mandible or maxilla, where limited bone height was available. The clinical crown-implant ratio was determined on digitized casts. Peri-implant bone changes were analyzed on intraoral radiographs. Prosthetic complications were scored throughout the evaluation period. RESULTS: The mean crown-implant ratio was 2.14 ± 0.42. The mean peri-implant bone loss was 0.13 ± 0.36 mm. No complications occurred. CONCLUSION: High crown-implant ratios are not accompanied by increased peri-implant bone changes or prosthetic complications during a 1-year follow-up period.

Clinical Bonding of Resin Nano Ceramic Restorations to Zirconia Abutments: A Case Series within a Randomized Clinical Trial.

BACKGROUND: New dental materials are introduced and promoted in the field without extensive clinical testing. Using those materials in a clinical setting might result in unacceptable early failure rates. PURPOSE: The purpose of this paper was to analyze bonding of a new dental restorative material to either zirconia stock abutments or zirconia customized abutments. MATERIALS AND METHODS: Fifty participants seeking single implant treatment were included in a prospective study. Resin Nano Ceramic (RNC, Lava Ultimate, 3M ESPE, Seefeld, Germany) crowns were digitally manufactured and extraorally bonded to either a stock or a customized zirconia abutment (ZirDesign and ATLANTIS, DENTSPLY Implants, Mölndal, Sweden) by means of a resin composite cement (RelyX Ultimate in combination with Scotchbond Universal, 3M ESPE), strictly following the manufacturer's recommendations. The final restorations were screw-retained to the implants and followed during 12 months. Primary outcome parameter was uncompromised survival of the restoration, and secondary outcome parameter was mode of failure. RESULTS: No implants were lost. The uncompromised survival rate of the RNC crowns bonded to zirconia abutments after 1 year of clinical service was only 14% (n = 7). Catastrophic failure occurred in three cases (6%), whereas bonding failure between RNC crowns and zirconia abutments occurred in 80% of the cases (n = 40) within the first year of service. No statistical significant difference in uncompromised survival rate could be identified between abutment types (χ2 = 1.495, p = .209). Uncompromised survival rate after 1 year was highly significantly different (χ2 = 104.173, p < .001) from a reference standard, which was set at 95%. CONCLUSION: RNC crowns luted to stock and customized zirconia implant abutments with the particular resin composite cement in this trial have a poor prognosis, regardless of the abutment type used.

A 15-Year Comparative Prospective Study of Surgical and Prosthetic Care and Aftercare of Overdenture Treatment in the Atrophied Mandible: Augmentation Versus Nonaugmentation.

BACKGROUND: Different treatment strategies for the atrophied mandible are described in literature. The need for long term care and aftercare for these strategies is sparsely described, however. PURPOSE: To prospectively assess the need for prosthetic and surgical care and aftercare of two implant treatment strategies for the atrophied mandible. MATERIALS AND METHODS: Forty edentulous elderly patients were randomly assigned according to a balanced allocation method to a treatment strategy: dental implants in combination with an augmentation procedure versus a nonaugmentation procedure. All surgical and prosthetic care and aftercare were scored from the first visit until 15 years after implant placement. RESULTS: Twenty elderly patients completed the 15-year follow-up. As expected, the augmentation group needed significantly more surgical time than the nonaugmentation group (338 vs 145 minutes), but the need for prosthetic care and surgical/prosthetic aftercare was comparable. Implant survival was lower in augmented mandibles (88.7% vs 98.7%, p < .05). Aftercare mainly consisted of routine inspections; the need for prosthetic adjustments was minor. Surgical aftercare was hardly needed. CONCLUSION: The only difference in the need for surgical and prosthetic (after) care was the extra time needed for performing augmentation surgery and the higher risk on implant loss in augmented mandibles. Otherwise, the need for care and aftercare was of the same magnitude. Thus, when applicable, nonaugmentation surgery is preferred as no general anesthesia is needed and the morbidity is low.

Treatment Outcome of Two Adjacent Implant-Supported Restorations with Different Implant Platform Designs in the Esthetic Region: A Five-Year Randomized Clinical Trial.

PURPOSE: The aim of this study was to evaluate the peri-implant soft and hard tissues and satisfaction in patients with two adjacent implant-supported restorations in the esthetic region, treated with two adjacent implants with a scalloped or flat platform. MATERIALS AND METHODS: The randomized clinical trial consisted of 40 patients allocated to either a scalloped implant group consisting of 20 patients or a flat implant group of 20 patients. Clinical and radiographic examinations were performed during a 5-year followup period, and patient satisfaction during the same period was assessed. RESULTS: The scalloped implant group showed significantly more marginal bone loss (scalloped: 3.2 ± 1.1 mm; flat: 1.5 ± 0.8 mm) and significantly greater bone loss at the interimplant bone crest (scalloped: 2.4 ± 1.0 mm; flat: 1.3 ± 1.0 mm). Furthermore, peri-implant soft tissues showed significantly more bleeding when provided with scalloped implants than with flat implants. Papilla index scores were low in both groups. Patient satisfaction was high in both groups. CONCLUSION: More bone loss and compromised interimplant papilla regeneration were noted around scalloped implants in the first year, and stable results were observed in the subsequent 4 years with both systems. Scalloped implants seem to offer no benefit when compared to conventional flat implants in the esthetic region.