Immediately provisionalized tapered conical connection implants for single-tooth restorations in the maxillary esthetic zone: a 5-year prospective single-cohort multicenter analysis.

OBJECTIVES: This open, single-cohort, multicenter, prospective study investigated the efficacy of immediately provisionalized tapered conical connection implant for single-tooth restorations in the anterior and premolar regions of the maxilla after 5 years of function. MATERIALS AND METHODS: All implants were placed in healed sites and immediately provisionalized. MBLs, soft-tissue parameters, and oral-health impact profile (OHIP) were evaluated at implant insertion, 6, 12, 24, 36, and 60 months. Paired Wilcoxon signed-rank tests and Kaplan-Meier survival analysis was used for statistical and implant survival/success analyses, respectively. RESULTS: Seventy-seven patients (81 implants) completed the 5-year follow-up. The 5-year cumulative survival and success rates were 97.8%, and the mean MBL change from implant insertion to 5 years was - 0.80 ± 1.13 mm. Optimal papilla index scores were observed at 90.1% of sites at 5 years compared with 32.8% of sites at insertion. Pink esthetic score, modified bleeding and plaque indices, and OHIP showed statistically significant improvement at the 5-year follow-up. CONCLUSIONS: Immediately provisionalized tapered conical connection implants promote marginal bone stability and excellent esthetic outcomes after 5 years of function. CLINICAL RELEVANCE: This treatment is a viable option for patients requiring immediately provisionalized single-tooth restorations in the esthetic zone and shows favorable long-term clinical outcomes, including marginal bone stability and excellent esthetics.

A prospective multicenter evaluation of immediately functionalized tapered conical connection implants for single restorations in maxillary anterior and premolar sites: 3-year results.

OBJECTIVES: This multicenter prospective clinical trial investigated immediately provisionalized, anodized, conical connection, tapered implants with platform shifting in maxillary anterior and premolar sites. MATERIALS AND METHODS: Patients requiring single-tooth implant-supported restorations in maxillary anterior and premolar sites were enrolled. Implants were immediately provisionalized and evaluated at insertion, 6 months, and annually thereafter. Outcome measures were marginal bone level change (ΔMBL), cumulative survival rate (CSR), and success rate, soft-tissue parameters, and oral health impact profile (OHIP). ΔMBL and Pink Esthetic Score were analyzed using Wilcoxon signed-rank tests. CSR was calculated using life table analysis. Other soft-tissue parameters were analyzed using sign tests. RESULTS: Of 94 enrolled patients (99 implants), 84 (88 implants) attended the 3-year follow-up. After an initial bone loss between implant insertion and 6 months (- 0.92 ± 1.23 mm), bone levels stabilized from 6 months to 3 years (0.13 ± 0.94 mm) with no significant change. The 3-year CSR was 98.9%, and the cumulative success rate was 96.9%. Papilla index scores of 2 or 3 were observed at 88.6% of sites at the 3-year visit compared with 32.8% at implant insertion. Improvements were observed for all other outcomes, including bleeding on probing, esthetics, plaque, and OHIP. CONCLUSIONS: This restorative protocol was associated with high primary stability, patient satisfaction, stable bone levels, and an overall improvement of the soft tissue outcomes over a 3-year period. CLINICAL RELEVANCE: The presented treatment is a viable option for single-tooth restorations of maxillary anterior teeth and premolars with successful short- to mid-long-term clinical outcomes.

An open prospective single cohort multicenter study evaluating the novel, tapered, conical connection implants supporting single crowns in the anterior and premolar maxilla: interim 1-year results.

OBJECTIVES: The aim of this multicenter prospective clinical study was to evaluate anodized tapered implants with a conical connection and integrated platform shifting placed in the anterior and premolar maxilla. MATERIALS AND METHODS: The study enrolled patients requiring single-tooth restorations in healed sites of maxillary anterior and premolar teeth. All implants were immediately temporized. Clinical and radiographic evaluations were conducted at implant insertion, 6 months, and 1 year. Outcome measures included bone remodeling, cumulative survival rate (CSR), success rate, soft-tissue health and esthetics, and patient satisfaction. Bone remodeling and pink esthetic score were analyzed using Wilcoxon signed-rank tests. CSR was calculated using life table analysis. Other soft-tissue outcomes were analyzed using sign tests. RESULTS: Out of 97 enrolled patients (102 implants), 87 patients (91 implants) completed the 1-year visit. Marginal bone remodeling was -0.85 ± 1.36 mm. After the expected initial bone loss, a mean bone gain of 0.11 ± 1.05 mm was observed between 6 months and 1 year. The CSR was 99.0%, and the cumulative success rate was 97.0%. Partial or full papilla was observed at 30.8% of sites at baseline, 87.2% at 6 months, and 90.5% at 1 year. Soft-tissue response, esthetics, and patient satisfaction all improved during the study period. CONCLUSIONS: Bone gain was observed following the expected initial bone loss, and soft-tissue outcomes improved suggesting favorable tissue response using anodized tapered conical connection implants. CLINICAL RELEVANCE: Rapid stabilization of bone remodeling and robust papilla regeneration indicate favorable tissue healing promoted by the conical connection, platform-shift design. TRIAL REGISTRATION: clinicaltrials.gov NCT02175550.

Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.

OBJECTIVES: The aim of the present investigation was the analysis of the factors presumptively affecting the accuracy outcome of cone-beam computed tomography (CBCT)-derived laboratory-based surgical guides for implant placement in partially edentulous patients. MATERIALS AND METHODS: In 52 partially edentulous patients a total of 132 implants were placed following CBCT diagnostics with the aid of laboratory-fabricated, tooth-borne templates. Based on the image fusion technique measurements were done to calculate linear and angular deviations between virtually planned and placed implants. The implant sites were stratified according to four factors that presumably may influence the transfer accuracy: (i) type of arch (maxilla/mandible), (ii) kind of template (single-tooth gap/interrupted dental arch/shortened dental arch/reduced residual dentition), (iii) surgical technique (flapless/open flap), (iv) number of sleeve-guided site preparation steps (fully guided placement/freehand placement/freehand final drilling). The data were analyzed using analysis of variance and the Bonferroni test. RESULTS: The transfer accuracy of shoulder level, apex level, and angulation was similar for maxilla and mandible as well as for flapless and open flap approach. The differences were small in magnitude and reached no or only a borderline statistical significance. At implant sites in the reduced residual dentition group, the discrepancies were more pronounced than in the single-tooth gap group, whereas no significant differences could be determined between free ending templates in the shortened dental arch and bilateral anchored templates in the interrupted dental arch. Implant placement through the guide allowed a more accurate implementation of the virtual plan to the surgical site than freehand insertion or freehand final drilling. CONCLUSION: CBCT-derived laboratory-based surgical templates enabled an implant placement in the cancellous maxilla as well as flapless procedures without compromising the transfer accuracy. The number and distribution of the remaining teeth as well as the number of sleeve-guided implant site preparation steps influenced the extent of deviation that can be achieved in partial edentulism.

Accuracy assessment of cone beam computed tomography-derived laboratory-based surgical templates on partially edentulous patients.

OBJECTIVES: The aim of the present prospective clinical study was to evaluate the match between the positions and axes of the virtually planned and the placed implants using laboratory-based surgical guides generated from cone beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 132 implants were placed with the aid of 3D-based transfer templates in 52 consecutive partially edentulous patients between April 2008 and March 2010. After individual adaptation of the scan templates and CBCT scanning, the acquired data for virtual implant planning and simulation were processed using the med3D software program. After finalizing the virtual placement of the implants the radiographic templates were converted into operative guides containing titanium sleeves for cavity preparation. Preoperative planning was merged with postoperative CBCT data to identify linear and angular deviations between virtually planned and placed implants. RESULTS: Compared with the planned implants the installed implants showed linear deviations in the median at the neck and apex of 0.27 mm (range 0.01-0.97 mm), and of 0.46 mm (range 0.03-1.38 mm), respectively. The angle deviation was 1.84° in median, with a range of 0.07-6.26°. The extent of deviation depends on the size of the tooth gap and the distribution of the remaining teeth. CONCLUSION: The results of this study suggested that laboratory-fabricated surgical guides using CBCT data may be reliable in implant placement under prosthodontic considerations in partial edentulism.

Three-dimensional analysis of bone formation after maxillary sinus augmentation by means of microcomputed tomography: a pilot study.

PURPOSE: Although many studies have analyzed the suitability of different grafting materials for maxillary sinus augmentation by means of histomorphometry in conventional histologic strains, the three-dimensional (3D) structure and remodeling of these grafts after healing beneath the sinus membrane remain unclear. The aim of the present study was to determine whether microcomputed tomography is a suitable method to evaluate the 3D structure and remodeling of grafts after sinus floor augmentation. MATERIALS AND METHODS: Sinus floor augmentation was performed in five patients using autogenous bone (AB) alone, AB and beta-tricalcium phosphate (b-TCP, Cerasorb), AB and b TCP/hydroxyapatite (HA) (BoneCeramic), AB and calcium carbonate (Algipore), and AB and HA (PepGen). Specimens from the grafted sites were harvested by means of a trephine bur 5 to 16 months after maxillary sinus augmentation. Microcomputed tomography of these specimens was performed with a nominal isotropic resolution of 6 x 6 x 6 µm² voxel size. After segmentation, 3D images were reconstructed, and the distribution of bone and substitute material was evaluated by means of volumetric and density measurements. RESULTS: In all images, both bone and substitute material could clearly be identified. The connectivity of trabeculae surrounding the substitute material was visible in the 3D reconstructions. Volumetric evaluation such as total bone volume, volume of substitute material, and trabecular thickness and spacing revealed differences between the different grafting materials. CONCLUSION: Microcomputed tomography is a promising method to evaluate the 3D structure of grafts after sinus floor augmentation with autogenous bone and bone substitute materials.

Randomized multicenter comparison of 2 IMZ and 4 TPS screw implants supporting bar-retained overdentures in 425 edentulous mandibles.

PURPOSE: Two treatment concepts for implant-supported bar retention of mandibular overdentures-2 intramobile cylinder (IMZ) implants and a Dolder bar and 4 titanium plasma-sprayed (TPS) screw implants and an angulated bar-were compared in a randomized controlled clinical trial with respect to postprosthetic efficacy and safety. MATERIALS AND METHODS: Four hundred twenty-five patients with edentulous mandibles were enrolled; 212 were randomized to TPS implants (control group) and 213 to IMZ implants (test group). Endpoints were occurrences of postprosthetic integration deficiency (ID), functional deficiency (FD), and complications. The trial was sized to detect a 10% difference in 5-year ID-free postprosthetic system lifetime with a power of 80%. RESULTS: With 340 protocol-completed cases, the trial achieved its predetermined power. The 2 systems did not show statistically significant differences in occurrences of postprosthetic ID and FD; 5-year occurrence-free postprosthetic system lifetime probabilities were estimated as 42.5% with IMZ and 42.8% with TPS, for ID; and as 82.6% with IMZ and 87.2% with TPS, for FD. However, at 3 to 6 months after surgery, mean Periotest values were significantly higher (P = .0001 without adjustment) with IMZ implants (5.6, SD 4.2) than with TPS implants (0.8, SD 4.3). TPS implants showed a higher incidence of inflammation and recession, while IMZ implants had a higher incidence of implant fracture after functional loading. DISCUSSION: The system-wise approach overcomes potential bias with implant-wise analyses. A combination of radiographic and clinical criteria distinguishes between desirable integration and functional anchorage. The in situ survival rates at 5 years in this study (95% for IMZ, 92% for TPS) match rates reported in the literature. CONCLUSION: This study demonstrated equivalent efficacy of 2 IMZ cylinders and 4 TPS screws in implant-supported, bar-retained mandibular overdentures and indicated a higher rate of complications with the TPS screw implants.

Residual ridge resorption in the edentulous maxilla in patients with implant-supported mandibular overdentures: an 8-year retrospective study.

PURPOSE: This retrospective study radiologically investigated alveolar bone resorption in the edentulous maxilla in patients with implant-supported mandibular overdentures. MATERIALS AND METHODS: This study consisted of 35 healthy, completely edentulous patients with a mean age of 59.7 years. They had received two implants between the mental foramina. New bar-retained mandibular overdentures and maxillary complete dentures were fabricated. Standardized panoramic radiographs taken subsequent to loading and at annual recall visits for up to 8 years were measured for alveolar bone loss in the maxilla. Bone areas and areas of reference not subject to resorption were measured with a planimetry program. The proportional value between both was expressed as a ratio (R). Bone loss was expressed as a change in R between two time points. Differences in the resorption rate between the anterior and posterior parts of the maxilla were investigated. RESULTS: Residual ridge resorption continued during the follow-up period and revealed high individual variability. With a range of 5% to 11% (median) loss in the original bone height, it was significantly (P < .031) more pronounced in the anterior than posterior maxilla (2% to 7%) from the second through eighth years. Regression analysis of the medians revealed a relatively high correlation between time and bone loss in both anterior and posterior parts of the maxilla. CONCLUSION: The anterior anchorage of mandibular overdentures by means of two implants and an ovoid bar was associated with slightly higher resorption in the anterior than in the posterior part of the edentulous maxilla.

Randomized multicenter comparison of two coatings of intramobile cylinder implants in 313 partially edentulous mandibles followed up for 5 years.

Intramobile cylinder (IMZ) implants with either of two coatings, hydroxyapatite (HA) or titanium plasma-flame (TPF), as distal abutments for combined tooth implant-supported restorations, were compared in 313 partially edentulous mandibles with respect to postprosthetical failure patterns and complication frequencies in a randomized multicenter clinical trial. Within the treatment protocols, the two coatings do not show evidence of different efficacy with respect to occurrence of postprosthetical integration deficiency (ID) or functional deficiency (FD). Statistical equivalence for an absolute effect of +/-15% in event-free survival could only be demonstrated for FD, not for ID, however. Intent-to-treat and per-protocol population analyses gave consistent results. Hazards of occurrence of ID and FD, adjusted for years of follow-up, were estimated for ID as 7% per year (95%CI 4-10% per year) with HA and 5% per year (95%CI 3-7% per year) with TPF, and for FD as 5% per year (95%CI 3-7% per year) with HA and 4% per year (95%CI 2-6% per year) with TPF. The 5-year cumulative success rates for no ID were 69.5% (95%CI 58-81%) with HA and 82.2% (95%CI 74-91%) with TPF. With respect to frequencies of complications, there was no relevant statistically significant difference between the two coatings.

A 5-year longitudinal study of the clinical effectiveness of ITI solid-screw implants in the treatment of mandibular edentulism.

PURPOSE: The aim of this longitudinal study was to gain 5-year clinical documentation of the 1-stage surgical technique in connection with ITI solid-screw implants used in the edentulous mandible. MATERIALS AND METHODS: One hundred patients with totally edentulous mandibles were treated with bar-retained overdentures supported by a total of 340 consecutively placed ITI solid-screw implants. The patients were followed at annual intervals for at least 5 years to evaluate implant success, longitudinal reactions of the peri-implant hard and soft tissues, and incidences of biologic and mechanical complications. RESULTS: During the trial period, a total of 4 implants failed, all prior to loading, and 51 implants were lost to follow-up, resulting in a cumulative survival rate of 98.8% after 5 years of functional service. The success analysis included additional strictly defined events (either "first occurrence of marginal bone loss > or = 4 mm" or "first occurrence of pocket depth > or = 4 mm" and "first occurrence of crevicular fluid flow rate > or = 2.5 mm) and resulted in a cumulative 5-year success rate of 95.7%. The median marginal bone loss experienced between implant placement and prosthetic treatment was 0.5 mm, followed by an annual bone level change of 0.1 mm for the functional period of 5 years. The increasing incidence of remarkable plaque deposits from 19% to 50% represented the difficulties of the patients in maintaining a high level of oral hygiene, particularly for the lingual surfaces. Sulcus Bleeding Index, probing depth, attachment level, and crevicular fluid flow rate were used to describe the health of the peri-implant soft tissues and remained almost within acceptable standards. DISCUSSION: Survival and success rates of implants, amount of marginal bone loss, and periodontal indices of peri-implant soft tissues were consistent with those reported in the literature regarding implants with the submerged healing concept. CONCLUSION: With a cumulative survival rate of 98.8%, a cumulative success rate of 95.7%, and a median marginal bone loss of 0.5 mm during the healing period, followed by an annual rate of 0.1 mm after loading, non-submerged ITI solid-screw implants confirm the good clinical outcome of implant-supported treatment concepts for the rehabilitation of totally edentulous patients in a medium-term perspective.