Morse Taper Connection Implants Research Articles

Short implants: Influence of different diameters, torques, and transmucosal heights of straight prosthetic abutments on screw preload loss after cycling.

This study evaluated the influence of different implant diameters, insertion torques, and transmucosal heights on the loosening of abutments installed on short implants, after mechanical cycling. The Morse taper connection implants (n=96) tested were 5mm high, divided according to the platform diameter: 4 or 6mm. A universal abutment was coupled to each implant (with different transmucosal heights: 1 or 5mm). The sets were subdivided into 20- and 32-Ncm torque. After the cycle fatigue test, the detorque values were measured with a digital torque indicator. After mechanical cycling, the mean detorque values obtained for the abutment with 20-Ncm insertion torque were lower than for implants with 32-Ncm insertion torque, regardless of the platform diameter or transmucosal height. In the 20-Ncm torque group, there was no statistically significant difference in the detorque values between platform diameters or transmucosal heights. Otherwise, for 32-Ncm sets, a smaller platform diameter (4mm), and a longer transmucosal height (5mm) showed the lowest detorque values. In conclusion, implants placed with 32-Ncm insertion torque and abutments with 1mm transmucosal height and a 6mm implant diameter demonstrated the highest detorque values.

Marginal Bone Level and Biomechanical Behavior of Titanium-Indexed Abutment Base of Conical Connection Used for Single Ceramic Crowns on Morse-Taper Implant: A Clinical Retrospective Study.

The goal of this retrospective clinical study was to evaluate the behavior of Morse-taper indexed abutments by analyzing the marginal bone level (MBL) after at least 12 months of function. Patients rehabilitated with single ceramic crowns between May 2015 and December 2020 received single Morse-taper connection implants (DuoCone implant) with two-piece straight abutment baseT used for at least 12 months, presenting periapical radiograph immediately after crown installation were enrolled. The position of the rehabilitated tooth and arch (maxilla or mandible), crown installation period, implant dimensions, abutment transmucosal height, installation site (immediate implant placement or healed area), associated with bone regeneration, immediate provisionalization, and complications after installation of the final crown were analyzed. The initial and final MBL was evaluated by comparing the initial and final X-rays. The level of significance was α = 0.05. Seventy-five patients (49 women and 26 men) enrolled had a mean period of evaluation of 22.7 ± 6.2 months. Thirty-one implant-abutment (IA) sets had between 12-18 months, 34 between 19-24 months, and 44 between 25-33 months. Only one patient failed due to an abutment fracture after 25 months of function. Fifty-eight implants were placed in the maxilla (53.2%) and 51 in the mandible (46.8%). Seventy-four implants were installed in healed sites (67.9%), and 35 were in fresh socket sites (32.1%). Thirty-two out of these 35 implants placed in fresh sockets had the gap filled with bone graft particles. Twenty-six implants received immediate provisionalization. The average MBL was -0.67 ± 0.65 mm in mesial and -0.70 ± 0.63 mm in distal (p = 0.5072). The most important finding was the statistically significant difference comparing the values obtained for MBL between the abutments with different transmucosal height portions, which were better for abutments with heights greater than 2.5 mm. Regarding the abutments' diameter, 58 had 3.5 mm (53.2%) and 51 had 4.5 mm (46.8%). There was no statistical difference between them, with the following means and standard deviation, respectively, -0.57 ± 0.53 mm (mesial) and -0.66 ± 0.50 mm (distal), and -0.78 ± 0.75 mm (mesial) and -0.746 ± 0.76 mm (distal). Regarding the implant dimensions, 24 implants were 3.5 mm (22%), and 85 implants (78%) had 4.0 mm. In length, 51 implants had 9 mm (46.8%), 25 had 11 mm (22.9%), and 33 implants were 13 mm (30.3%). There was no statistical difference between the abutment diameters (p > 0.05). Within the limitations of this study, it was possible to conclude that better behavior and lesser marginal bone loss were observed when using abutment heights greater than 2.5 mm of transmucosal portion and when placed implants with 13 mm length. Furthermore, this type of abutment showed a little incidence of failures within the period analyzed in our study.

The Effect of Occlusal Contacts in the Stress Concentration of Implant-Supported Zirconia Restorations

The present article evaluated the effect of occlusal contacts in the stress concentration of implant-supported zirconia restorations, with Morse-taper connection implants. One implant model was analyzed according to the loading region (center of the crown or working cusp). Both systems received cement-retained zirconia crown. The peri-implant tissue was created as an isotropic resin, that has been fixed. The load of 500 N was applied in two different regions (center of the crown or working cusp). The results were analyzed in terms of von-Mises stress. The materials were assumed as isotropic, homogeneous, linear and elastic. The results showed that there is difference regarding the loading method for the calculated stress. The working cusps loadings increased the stress in the crown and the prosthetic connections. In conclusion, the occlusal contact region can modify the implant biomechanical behavior. In addition, the dentists should proper plan the prosthetic crown to reduce the stress in the zirconia crowns.

Analysis of Torque Maintenance and Fracture Resistance after Fatigue in Retention Screws Made of Different Metals for Screw-Retained Implant-Borne Prosthesis Joints.

Purpose The aim was to evaluate the effect of different metallic alloys used in the manufacture of retention screws for universal cast to long abutment (UCLA) abutments for external hexagon (HE) and Morse taper (MT) connection implants, as well as of mechanical cycling on torque maintenance and fracture resistance through electromechanical fatigue testing by mastication followed by compression testing. Methods Sixty implants were used, 30 MT and 30 HE, with their respective titanium UCLA abutments and retention screws of 5 different materials (n = 6): Ti cp grade 2, Ti cp grade 4, Ti cp grade 4 hard, Ti grade 5—Ti6Al4V and surgical steel (DSP® Biomedical). The assemblies were positioned in an electromechanical masticatory fatigue testing machine. The fracture strength test was performed by compression testing in a universal testing machine EMICDL-200. Results The cycled screws and new screws of each alloy group for each connection type were evaluated, obtaining the maximum force (FM), in order to verify the effect of mechanical cycling. The data were tabulated and submitted to appropriate statistical analysis (α = 0.05). Conclusion It was concluded that for the MT, the alloy with the best performance was steel, both in the maintenance of torque and in the compression test, and cycling negatively influenced the maintenance of preload for this connection. The alloy material did not influence torque maintenance for HE. The new screws that were subjected to EMIC showed higher strength. The alloy with the lowest strength was Ti grade 2.

Surgical and Prosthetic Outcomes of 967 Implants Under Immediate or Delayed Loading in Full-Arch Rehabilitation: a Retrospective Study With up To 5 Years of Follow-Up

Objective: The aim of this study was to evaluate implant and prosthesis survival rates in full-arch rehabilitation supported by implants with platform-switched Morse taper connection submitted to immediate or delayed loading, after up to 5 years of follow-up. Material and Methods: Data was retrospectively collected from clinical records of patients who were treated by means of implant-supported full-arch rehabilitation. Survival rates of implants and prostheses were evaluated according to immediate or delayed loading. Results: The sample comprised 967 implants. Of those, 627 were submitted to immediate loading (IL) while 340 to delayed loading (DL). After a follow-up period of up to 5 years, the implant survival rate for IL was of 99.7% (622/627 implants) and 97.2% (333/340 implants) for DL. The overall implant survival rate was 98.8% (955/967 implants). Prosthesis survival rate was 100% (N = 178) for both groups. Significantly more implants in the DL group presented bone loss (p > 0.01), either greater or lower than 2 mm, during the follow-up period. Conclusion: Within their limits, the present results suggest that full-arch rehabilitation with platform-switched Morse taper connection implants can lead to surgical and prosthetic predictable outcomes. Moreover, immediate loading protocol seems to be a good option for the rehabilitation of fully edentulous patients, as it involves a shorter treatment time, which may lead to greater patient satisfaction. Keywords Dental implants; Rehabilitation; Survival rate; Retrospective study.

Effect of Different Framework Materials in Implant-Supported Fixed Mandibular Prostheses: A Finite Element Analysis.

To evaluate the biomechanical behaviors of different framework materials in implant-supported fixed mandibular prostheses using three-dimensional (3D) finite element analysis. A model of a severely resorbed edentulous mandible was obtained from a tomography database. Morse taper-connection implants and multi-unit abutments were cut with an electro-erosion machine and scanned using a 3D scanner. The implants were positioned on the model at the bone level and distributed equally to support a fixed complete prosthesis. The simulations were divided into six groups according to the framework material: titanium (Ti); cobalt-chromium (Co-Cr); zirconia (ZrO2); polyether ether ketone (PEEK); carbon fiber-reinforced polyether ether ketone (CFR-PEEK); and polymethyl methacrylate (PMMA). The resultant load applied was obtained from the masseter, temporal, lateral, and medial pterygoid muscles. The principal stresses and von Mises equivalent stresses were analyzed and compared among the framework materials, and the results were described both quantitatively and qualitatively. PEEK and PMMA frameworks showed the highest total deformation values, showing decreases of von Mises stresses in the frameworks, implants, and abutments, but with a high tensile stress in the trabecular bone that achieved critical values. CFR-PEEK frameworks achieved their failure limit, whereas the ZrO2, Co-Cr, and Ti frameworks exhibited principal stresses in the bone region within physiologic limits. From a biomechanical point of view, the Ti, Co-Cr, and ZrO2 frameworks demonstrated the most favorable outcomes.

Early-predictors of marginal bone loss around morse taper connection implants loaded with single crowns: A prospective longitudinal study.

Few studies estimated the joint effect of implant design (length and diameter), peri-implant, and occlusal variables on early marginal bone loss. The monitoring of these factors during the first year after implant loading may be effective in preventing early implant failure. This prospective longitudinal study aimed to identify early-predictors of marginal bone loss around morse-tapered connection implants 12months after implant loading. Participants (n=33) received 109 morse taper implants inserted subcrestally (diameter: 3.5 to 5mm, length: 6 to 15mm) loaded with single crowns. Implants were radiographically examined at the implant placement (baseline) and 12months after prosthetic loading. Implant, peri-implant, and occlusal-related independent variables were analyzed by decision tree analysis. Mixed-effects multilevel analysis was used to estimate adjusted predictive values of marginal bone loss based on the early-predictors identified in decision tree analysis. Higher marginal bone loss was observed at mesial (mean of 0.87mm; ranged from 0.5 to 1.19) than at distal sites (mean of 0.73mm; ranged from 0.4 to 1.12mm). The predictive model revealed of the largest marginal bone loss in association with cement-retained prostheses, a platform diameter of 3.5mm, papilla sizes up to 2mm, keratinized mucosa width inferior to 3mm, implant lengths above 8.5mm, inadequate occlusal relations, presence of bleeding on probing and deep peri-implant pocket. As implant dimensions, peri-implant and occlusal-related factors were associated with early marginal bone loss around morse taper implant, intervention in these factors might prevent early marginal bone loss.

Short (7–8 m) morse taper connection implants placed in posterior jaws for single crowns – 3‐year prospective study

Short (7–8 m) morse taper connection implants placed in posterior jaws for single crowns – 3‐year prospective study

Do Oblique Cyclic Loads Influence the Tensile Strength of Different Morse Taper Connection Abutments?

The purpose of this in vitro study was to evaluate the behavior of abutments attached to Morse taper connection implants, with and without internal index, against oblique cyclic loads. Twenty test pieces composed of abutments connected to Morse taper implants solely by friction action were subdivided into two groups (n = 10): group NI (no index) and group I (index). The test units were submitted to tensile tests, before and after cycling loads. Paired t tests were used for intragroup data at different times, and independent t tests were used for the comparisons between the groups. There was a statistically significant difference in both the groups when the precycling and postcycling tensile values were compared. In the comparison between the no index and index groups, there was no statistically significant difference in precycling and postcycling tests. Within the limitations of this in vitro study, it can be concluded that the cyclic loads increased the tensile strength of abutments on Morse taper implants regardless of the index presence. On the other hand, the presence of an index did not significantly alter the values of tensile tests, before and after cyclic loads.

A Novel Full-Digital Protocol (SCAN-PLAN-MAKE-DONE®) for the Design and Fabrication of Implant-Supported Monolithic Translucent Zirconia Crowns Cemented on Customized Hybrid Abutments: A Retrospective Clinical Study on 25 Patients.

Purpose: To present a novel, full-digital protocol for the design and fabrication of implant-supported monolithic translucent zirconia crowns cemented on customized hybrid abutments. Methods: The present retrospective clinical study was based on data from patients who had been treated with single Morse-taper connection implants (Exacone®, Leone Implants, Florence, Italy) and were prosthetically restored with monolithic translucent zirconia crowns, cemented on customized hybrid abutments. The full-digital protocol (SCAN-PLAN-MAKE-DONE®) consisted of 8 phases: (1) intraoral scan of the implant position with scanbody; (2) computer-assisted design (CAD) of the individual abutment (saved as “supplementary abutment design” in external folder) and temporary crown; (3) milling of the individual zirconia abutment and of the temporary polymethyl-methacrylate (PMMA) crown, with extraoral cementation of the zirconia abutment on the relative titanium bonding base, to generate an individual hybrid abutment; (4) clinical application of the individual hybrid abutment and cementation of the temporary PMMA crown; (5) two months later, intraoral scan of the individual hybrid abutment in position; (6) CAD of the final crown with margin line design on the previously saved “supplementary abutment design”, superimposed on the second scan of the abutment in position; (7) milling of the final crown in monolithic translucent zirconia, sintering, and characterization; and (8) clinical application of the final crown. All patients were followed for a period of 1 year. The primary outcomes of this study were the marginal adaptation of the final crown (checked clinically and radiographically), the quality of occlusal and interproximal contact points at delivery, and the aesthetic integration; the secondary outcomes were the 1-year survival and success of the implant-supported restoration. An implant-supported restoration was considered successful in the absence of any biological or prosthetic complication, during the entire follow-up period. Results: In total, 25 patients (12 males, 13 females; 26–74 years of age; mean age 51.1 ± 13.3 years) who had been restored with 40 implant-supported monolithic translucent zirconia crowns were included in this study. At delivery, the marginal adaptation was perfect for all crowns. However, there were occlusal issues (2/40 crowns: 5%), interproximal issues (1/40 crowns: 2.5%), and aesthetic issues (1/40 crowns: 2.5%). The overall incidence of issues at delivery was therefore 10% (4/40 crowns). At 1 year, one implant failed; thus the survival of the restorations was 97.5% (39/40 crowns in function). Among the surviving implant-supported restorations, three experienced complications (one loss of connection between the hybrid abutment and the implant, one decementation of the zirconia abutment, and one decementation of the zirconia crown). The success of restorations amounted to 92.4%. Conclusions: The restoration of single Morse-taper connection implants with monolithic translucent zirconia crowns cemented on customized hybrid abutments via the novel SCAN-PLAN-MAKE-DONE® full-digital protocol seems to represent a reliable treatment option. However, further studies on a larger number of patients and dealing with different prosthetic restorations (such as implant-supported fixed partial prostheses) are needed to confirm the validity of this protocol.

Prosthetic Complications Affecting Single-Tooth Morse-Taper Connection Implants.

To evaluate the long-term cumulative implant survival rate (CISR%) and cumulative implant-crown success rate (CICSR%) of single-tooth Morse-taper connection implants, with particular attention to documenting the incidence of prosthetic complications. The customized records of all patients who had been treated with single-tooth Morse-taper connection implants in 2 dental centers during the period between January 2002 and December 2012 were revisited. These records included patient-related (gender, age at surgery, smoking, bruxism), implant-related (date of insertion, site/location, and length/diameter of the implant, previous/concomitant bone regeneration), and restoration-related (date of delivery of the provisional and final crown) information. In addition, these records contained information about any implant failure and biologic and/or prosthetic complication that occurred during the follow-up period as well as the radiographic documentation. The follow-up period comprised between 5 and 15 years. The main outcomes were CISR% and CICSR%, with the latter being defined as the condition in which no complication had affected the surviving implant-supported crown during the entire follow-up. Life-table analysis was used for the analysis of CISR% and CICSR%. Peri-implant marginal bone resorption (PIMBR) at 5, 10, and 15 years was a secondary outcome of this study. In total, 578 patients who had received 612 implants were included in this study. The overall CISR% at 15 years was 94.8% (94.2% maxilla, 95.3% mandible). Among the surviving crowns, the overall CICSR% at 15 years was 94.5% (93.1% and 94.9% for anterior and posterior crowns, respectively), and the incidence of prosthetic complications was low (1.5%). The PIMBL amounted to 0.38 ± 0.29 mm, 0.49 ± 0.35 mm, and 0.94 ± 0.58 mm at the 5-, 10-, and 15-year follow-ups, respectively. Morse-taper connection implants represent a reliable treatment procedure for the restoration of single-tooth gaps in the long term, with high CISR% (94.8%) at 15 years, a very low incidence of complications, and a high CICSR% (94.5%).

Influence of Abutment Surface Treatments on Screw Loosening of Morse Taper Implants.

To evaluate the effect of blasting and bonding on abutment surface to prevent screw loosening in Morse taper connections. Twenty-eight Morse taper connection implants were divided into 4 groups: no treatment (G1), blasting (G2), bonding (G3), and blasting + bonding (G4). In groups G2 and G4, the abutments were blasted with aluminum oxide granules; in groups G3 and G4, the conical abutment region was covered with a thin layer of bond thread lock agent. In all implants, the abutment-implant joint was tightened at a torque of 35 Ncm. The specimens were submitted to the mechanical cycling, under an oblique load for 1.0 × 10 cycles. The torque was measured with a digital torque meter. Data were analyzed by the t test, one-way analysis of variance, and Tukey tests (95%). The loosening strength was significantly higher in group G4 (35.83 ± 3.02 Ncm). There was no significant difference among groups G1 (25.86 ± 1.96 Ncm), G2 (25.86 ± 3.29 Ncm), and G3 (26.14 ± 2.12 Ncm). The association of blasting and bonding on abutment surface can be used to prevent screw loosening in Morse taper implants.

Clinical Comparison of Screw-Retained and Screwless Morse Taper Implant-Abutment Connections: One-year Postloading Results.

The purpose of this study was to clinically evaluate the screwless Morse taper implant-abutment connection type, in which the retention screw is totally eliminated, in terms of stability, success, periodontal parameters, and marginal bone levels after 1 year of function by comparing it with a passive fit internal implant-abutment connection, wherein a space exists between the matching components. Each edentulous subject received an implant with a screwless Morse taper connection (MT) in the left canine area of the mandible and an implant with a screw-retained implant-abutment connection (SR) in the right canine area of the mandible. All implants were loaded 6 weeks later. All cases were restored with a cemented bar-retained mandibular overdenture opposing a maxillary complete denture. Clinical recalls at 6 months and 12 months postloading were scheduled and the MT and SR implants were compared in terms of success, survival, primary and secondary implant stability, marginal bone loss, soft tissue response, and mechanical complications. The results were statistically analyzed. A total of 20 subjects were included (10 females, 10 males; average age: 61.60 years) and a total of 40 implants were inserted. No implant failure or technical problem was detected for either MT or SR implants. Marginal bone loss around MT and SR implants did not show any significant differences at 6 weeks after surgery (time of loading) or at 6 months or 12 months postloading (P > .05). Periodontal parameters such as gingival index and probing pocket depth of MT and SR implants likewise did not differ significantly at 6 months and 12 months postloading (P > .05). Primary stability values of MT and SR implants did not differ significantly when measured with the insertion torque device (mean of 68.10 Ncm for MT and 64.20 Ncm for SR implants; P = .564), nor when measured with the electronic percussive testing device (mean of -5.30 for the MT and -5.35 for the SR implants; P = .398). However, MT implants showed lower stability at the time of loading (6 weeks) and 6 months postloading (P = .037 and P = .003, respectively). Stability values did not show any significant differences 12 months postloading (P > .05). Within the limitations of this clinical study, it can be concluded that implants with screwless Morse taper and passive fit internal connections show comparable technical and biologic results after 1 year of function.

Morse Taper Connection Implants Placed in Grafted Sinuses in 65 Patients: A Retrospective Clinical Study with 10 Years of Follow-Up.

Purpose To investigate the 10-year survival and complication rates of Morse taper connection implants (MTCIs) placed in grafted sinuses. Methods This study reports on patients treated with maxillary sinus augmentation (with the lateral window technique (LWT) or the transalveolar osteotomy technique (TOT)) and installed with MTCIs supporting fixed restorations (single crowns (SCs) and fixed partial dentures (FPDs)), in two dental clinics. The outcomes of the study were the 10-year implant survival and complication rates. Results Sixty-five patients (30 males and 35 females) with a mean age of 62.7 (±10.2) years were installed with 142 MTCIs: 79 fixtures were inserted with the LWT and 63 were placed with the TOT. After ten years, five implants failed, for an overall survival rate of 96.5%. Three implants failed in the LWT group, for a survival rate of 96.3%; two implants failed in the TOT group, for a survival rate of 96.9%. The 10-year incidence of biologic complications was 11.9%. Prosthetic complications were all technical in nature and amounted to 7.6%. Conclusions MTCIs seem to represent a successful procedure for the prosthetic restoration of the grafted posterior maxilla, in the long term. This study was registered in the ISRCTN registry with number ISRCTN30772506.

Peri-implant bone loss around platform-switched Morse taper connection implants: a prospective 60-month follow-up study

The aim of this study was to measure the crestal bone level changes at 60 months of follow-up and to evaluate the influence of biologically relevant, anatomical, and implant-related variables. A prospective study design was used. STROBE guidelines were followed. A total of 576 implants were inserted in 270 patients needing an implant-supported, partial, fixed dental prosthesis or a single crown. Standardized peri-apical radiographs were obtained at 2 months (time of implant–abutment connection and prosthetic loading) and 60 months of follow-up. Descriptive statistics were used and inter- and intra-examiner reliability determined. A mixed model was used to evaluate the predictor variables. The correlation among multiple implants inserted in a single patient was considered. Significance was assessed using the type 3 test. Sensitivity analyses, least-squares means analyses, t-tests, and χ2 tests were also conducted. The statistical analysis was performed at the implant level; P<0.05 indicated statistical significance. At the 60-month follow-up, the mean marginal bone remodelling was −0.59±1.34mm (range −5.70 to 3.65mm). Marginal bone loss was significantly influenced by implant depth, implant location, and the interactions implant depth×jaw, implant location×timing of implant placement, and jaw×implant diameter. At the 60-month follow-up, a low mean marginal bone loss was found, which was significantly higher with subcrestal implants and anterior implants.

Marginal Bone Loss around Morse Taper Connection Implants in Osseointegration Period

Reason and purpose of the study: Bone loss, particularly at the level of the marginal bone crest, continues to be one of the main complications of implant treatment that compromises osseointegration and the rehabilitation. The aim of the present study was to evaluate radiographic marginal bone loss around short Morse taper connection implants and the survival rate of these implants 7, 30 and 90 days after placement in severely resorbed jaws. Methods: Twelve patients were divided into two groups: a study group consisting of 20 implants measuring 6 mm in length and 3.75 mm in diameter, and a control group consisting of 20 implants measuring 8 mm in length and 3.75 mm in diameter. All surgeries were performed according to the protocol of morse taper connection implant of the Kopp System. The results were compared by one-way analysis of variance and the Tukey test. Results: There was no significant difference between groups at any of the time points studied. The mean bone crest/implant shoulder distance was 1,36 mm (SD=1.01) on the mesial surface and was 1,10 mm (SD=0.87) on the distal surface for the 6-mm implants and 1,42 mm (SD=0.83) on the mesial surface and was 1,15 mm (SD=0.76) on the distal surface for the 8-mm implants after 90 days of implant placement. Two of the 40 implants were lost (one per group), corresponding to a survival rate of 95%. Conclusion: Within the limitations of this study, we conclude that 6-mm long Morse taper connection implants present levels of crestal bone remodeling similar to those of 8-mm long implants.

A 36-month follow-up prospective cohort study on peri-implant bone loss of Morse Taper connection implants with platform switching.

A prospective cohort study was designed to measure marginal bone level changes at 36-month follow-up and to evaluate the influence of biologically relevant, anatomic and stress-related variables. STROBE guidelines were followed. Totally, 748 implants were inserted into 350 patients. Standardized periapical radiographs were taken at 2- (stage-two surgery), 12-, 24-, and 36-month follow-ups. Descriptive statistics were used and inter- and intra-examiner reliability were determined. A mixed-model was used to evaluate predictor variables. Statistical analysis was performed at implant level (statistical significance: P < 0.05). A total of 34 (4.5%) implants failed; of the 34 implants, 6 were early failures (0.8%) and 28 were late failures (3.7%). A total of 576 implants reached 36-month follow-up (mean follow-up: 25.58 months; SD: 10.32). Mean marginal bone remodeling was -0.56 mm. (SD: 1.30; range: -6.80 ± 3.65). A statistically significant, higher marginal bone loss was found for subcrestal implants and subcrestal implants inserted into the maxilla, for implants inserted into patients aged over 50 years, and for early-delayed implants inserted into patients aged over 50 years. In conclusion, a low, mean crestal bone loss at 36-month follow-up was recorded but implant positioning in the apico-occlusal dimension was found to be the most significant variable that influenced bone loss. (J Oral Sci 58, 49-57, 2016).

Facial Peri-implant Soft Tissue Topography of Posterior Single Implant-Supported Restorations and Relationship to Adjacent Teeth: A Retrospective Analysis.

The aim of this study was to retrospectively evaluate the factors affecting facial peri-implant mucosa topography of posterior single implant-supported restorations. The cohort comprised 25 patients with a single implant-supported restoration with platform switching and Morse taper-connection implants. Patients were divided into three groups based on facial soft tissue topography. Patients of group A (n = 8), group B (n = 9), and group C (n = 8) had a facial peri-implant tissue margin at the level of, coronal to, and apical to the zenith of the facial gingival margins of the adjacent teeth, respectively. Variables possibly associated with the facial peri-implant tissue margin level were obtained from clinical measurements, periapical radiographs, and cone beam computed tomograms. Implants in group C were placed in a more subcrestal position than implants of group B (1.50 ± 0.53 mm vs 0.44 ± 0.88 mm). Implants in group C had their platform in a more apical position in relation to the bone level of the adjacent teeth than implants of group B (3.45 ± 1.32 mm vs 1.53 ± 1.17 mm). The horizontal distance between adjacent teeth was greater for group C than for group A and group B (13.53 ± 2.37 mm vs 10.65 ± 2.09 mm and 9.82 ± 1.77 mm, respectively). In this study, facial peri-implant mucosa margins for implants in the posterior region with platform switching and a Morse taper connection were significantly affected by the distances from the implant platform to the buccal aspect of the ridge at the time of implant placement and from the implant platform to the bone level of the adjacent teeth and by the horizontal spaces between the adjacent teeth.

Measurement of loosening torque of prosthetic components in Morse taper connection implants

AIM: The aim of this study was to verify two different types of interfaces in Morse taper connection implants, relating the mechanical resistance to a loosening torque that is required to separate or move the prosthetic abutment. MATERIAL AND METHODS: Ten Morse taper connection implants and their respective abutments were divided into two groups (n = 5), DH (double hexagon) interface and OI (octagonal implant) interface. A standard insertion of implants was performed in a stainless steel base, where each abutment received a sequence of two consecutive tightening torques at a 10-minute interval, followed by a loosening torque, which was measured using a digital torque gauge. The Student’s t-test with a 5% significance level was used for data analysis. RESULTS: The results showed a statistically significant difference in the loosening torque values compared with DH torque values (p &lt; 0.05). However, the difference between tightening and loosening torque values was not statistically significant in the OI group (p = 0.465). CONCLUSION: The study concluded that there was a difference in the torque required to loosen the abutment screws between the DH group and the OI group, with the latter showing better results.

Esthetic Evaluation of Implants Placed after Orthodontic Treatment in Patients with Congenitally Missing Lateral Incisors

The aim of this retrospective study was to evaluate the esthetic outcome of single tooth Morse taper connection implants used to replace congenitally missing lateral incisors after orthodontic treatment by means of the pink esthetic score (PES) and white esthetic score (WES) index. Twenty consecutive patients who were treated with a single tooth Morse taper connection implants (Leone Implant System®, Florence, Italy) were enrolled in this study. An independent calibrated examiner applied the PES/WES index to 20 implant-supported restorations 3 months and 3 years after implant placement. No implants were lost. All 20 implants fulfilled the established success criteria for dental implants with regard to osseointegration and prosthetic complications, with an overall implant-crown success of 100.0%. At the 3 year examination, the mean distance between the implant shoulder and the first visible bone-implant contact was of 0.49 ± 0.18 mm (95% confidence interval 0.41-0.57); the mean PES was 8.15 ± 1.69, and the mean WES was 8.70 ± 0.92. The placement of single-tooth Morse taper connection implants for rehabilitation of congenitally missing lateral incisors after orthodontic treatment represents a successful procedure in the medium term. Further studies are necessary in order to assess the long-term esthetic score. This paper evaluates the esthetic outcome of Morse taper connection implants placed to restore congenitally missing lateral incisors after orthodontic treatment.