Single crowns in the posterior maxilla supported by either 11-mm long implants with sinus floor augmentation or by 6-mm long implants: A 10-year randomized controlled trial.

OBJECTIVES: To compare the clinical performance of single crowns in the posterior maxilla supported by either 11-mm long implants combined with maxillary sinus floor augmentation (MSFA) surgery or by 6-mm long implants during a 10-year follow-up period. MATERIALS AND METHODS: Subjects were randomly allocated to receive one 11-mm long implant in combination MFSA or to receive one 6-mm long implant without any grafting. Twenty-one implants in 20 patients were placed in the 6-mm group and 20 implants in 18 patients were placed in the 11-mm group. Both groups were followed by clinical and radiographic examinations up to 10 years. Patients' satisfaction was also scored before treatment. RESULTS: Two patients died and eight patients moved during the follow-up. Two patients lost an implant in the 6-mm group and one implant was lost in the 11-mm group (implant survival 89.5% and 90.9%, respectively). From loading to 10 years' follow-up, mean ± SE marginal bone loss in the 6-mm group and 11-mm group was 0.18 ± 0.10 mm and 0.26 ± 0.12 mm, respectively, without a significant difference between the groups at 10 years (p = .650). In both groups, indices scores for plaque, calculus, gingiva and bleeding were low as well as mean pocket probing depth. Patients' satisfaction at 10 years was high in both groups; mean overall satisfaction in the 6-mm group and 11-mm group was 9.6 ± 0.6 and 9.2 ± 0.8, respectively (p = .168). CONCLUSIONS: Placement of 6-mm implants or 11-mm implants combined MFSA are equally successful during a 10-year follow-up period when applied for supporting a single restoration.

Comparison of 6-mm and 11-mm dental implants in the posterior region supporting fixed dental prostheses: 5-year results of an open multicenter randomized controlled trial.

OBJECTIVE: The aim of this multicenter, randomized controlled trial was to compare the clinical and radiographic outcomes of 6-mm or 11-mm implants, placed in the posterior maxilla and mandible, during a 5-year follow-up period. MATERIALS AND METHODS: Ninety-five patients with adequate bone height for 11-mm implants, were randomly allocated to a 6-mm group (test group with short implants) or an 11-mm group (control group with standard-length implants). Two or three implants of the same length were placed in each patient and after 6 weeks loaded with a splinted provisional restoration. This was followed by definitive splinted restoration 6 months after implant placement. Clinical and radiographic parameters, including the occurrence of complications were recorded. RESULTS: A total of 49 patients were enrolled to receive 6-mm implants (n = 108) and 46 patients to receive 11-mm implants (n = 101). Three implants (two of 6 mm and one of 11 mm in length) were lost before loading and one 6-mm implant after 15 months of function, and one 11-mm implant was lost during the first year of function. The 5-year survival rates were 96.0% and 98.9% in the 6-mm and 11-mm group, respectively. The mean marginal bone level changes 5 years post-loading were 0.01 ± 0.45 mm (bone gain) in the 6-mm group and -0.12 ± 0.93 mm (bone loss) in the 11-mm group (p = .7670). Clinical parameters, including plaque, bleeding on probing and pocket probing depth were not significantly different between the groups, and also technical complications were low. CONCLUSION: The clinical and radiographic outcomes of 6-mm short and 11-mm standard-length implants were not different during a 5-year evaluation period.

Marginal bone level and survival of short and standard-length implants after 3 years: An Open Multi-Center Randomized Controlled Clinical Trial.

OBJECTIVES: The present multi-center randomized controlled clinical trial sought to compare the marginal bone level (MBL) changes and survival of 6- and 11-mm implants. MATERIAL AND METHODS: Ninety-five patients receiving a total of 209 dental implants were enrolled. Subjects were randomly allocated to two cohorts: test (4.0 × 6 mm; N = 108) or control (4.0 × 11 mm; N = 101) implant groups. To be randomized, all edentulous sites were anatomically qualified to receive 11 mm implant. Two to three implants were placed in maxillary or mandibular posterior regions and loaded with splinted provisional restoration after 6 weeks and definitive restoration 6 months thereafter. Test and control implants were followed by clinical and radiographic examinations on an annual basis up to 3 years. RESULTS: Radiographic assessment of MBL 3 years after loading revealed the bone to be located at 0.27 mm (±0.40) and 0.44 mm (±0.74) apical to the implant platform in the test and control groups, respectively. During the 3 years of follow-up since loading, 0.04 mm (±0.43) MBL gain and 0.02 mm (±0.76) of MBL loss were observed in the 6-mm (test) and 11-mm (control) groups, respectively. The MBL's for test and control were significantly different (p = 0.000) in favor of short implants. The cumulative survival rates from placement after 3 years were 96% and 99% for the 6- and 11-mm implants, respectively, with no statistical significance. CONCLUSIONS: Reconstruction of partially edentulous posterior maxilla or mandible with 6- or 11-mm implants led to stable marginal bone level and high implant survival rate after 3 years.

Biomechanical aspects: Summary and consensus statements of group 4. The 5th EAO Consensus Conference 2018.

OBJECTIVES: The aim of the present publication was to report on the EAO Workshop group-4 discussions and consensus statements on the five reviews previously prepared. These reviews provided the scientific evidence on the effect of crown-to-implant ratio, on reconstructions with cantilevers in fully and partially edentulous patients, on biological and technical complications of tilted in comparison with straight implants, and on the effects of osseointegrated implants functioning in a residual dentition. MATERIAL AND METHODS: The group discussed, evaluated, corrected where deemed appropriate, and made recommendations to the authors regarding the following five reviews submitted: (a) Is there an effect of crown-to-implant ratio on implant treatment outcomes?; (b) Implant-supported cantilevered fixed dental rehabilitations in fully edentulous patients; (c) and in partially edentulous patients; (d) Biological and technical complications of tilted implants in comparison with straight implants supporting fixed dental prostheses; (e) What are the adverse effects of osseointegrated implants functioning among natural teeth of a residual dentition? Based on the five manuscripts and the discussion among the group as well as the plenum members, the major findings were summarized, consensus statements were formulated, clinical recommendations were proposed, and areas of future research were identified. RESULTS: Crown-to-implant ratios ranging from 0.9 to 2.2 did not influence the occurrence of biological or technical complications also in single-tooth restorations. Reconstructions with cantilevers for the rehabilitation of fully and partially edentulous jaws showed high implant and reconstruction survival rates. In contrast, the rate of complications-in particular associated with veneering material-was high during the observation period of 5-10 years. The data reported were primarily derived from studies with high risk of bias. The data for single-implant reconstructions were small. There was no evidence that distally tilted implants were associated with higher failure rates and increased amounts of marginal bone loss. The data supporting these findings, however, were at high risk of bias and frequently incompletely reported. Frequent positional changes occurred between the natural teeth and the implant-supported restorations. These changes were more pronounced in younger individuals, and even though they were reduced with age, they still occurred in adult patients. Even though these changes were frequent, potential implications for the patient are unclear. CONCLUSIONS: The use of single-tooth restorations with crown-to-implant ratio in between 0.9 and 2.2 may be considered a viable treatment option. Multiunit reconstructions with cantilevers are a viable treatment option in fully and partially edentulous patients. Clinicians and patients should be aware, however, that complications are frequent and primarily related to resin material used for veneering. There is some evidence that tilting an implant does affect stability of the implant and the surrounding bone. Treatment options to tilted implants should carefully be considered, as the effect on soft tissues and on prosthesis behavior is poorly reported for tilted implants. Positional changes in the dentition in relation to implant-supported restorations occur frequently. The patient should be informed about the possible need for a treatment related to these changes in the long term.

Single crown restorations supported by 6-mm implants in the resorbed posterior mandible: A 10-year prospective case series.

PURPOSE: To assess marginal bone level changes, implant and restoration survival, condition of the peri-implant mucosa, and the patient's satisfaction with the single restoration supported by a 6-mm long implant in the posterior mandible after 10 years in function. MATERIALS AND METHODS: Twenty-one consecutive patients missing premolars or molars in the posterior mandible, with a bone volume consisting of a width of at least 6 mm and an estimated height of 8 mm between the top of the ridge and alveolar nerve, were included. Each patient received one or more 6-mm implants. After 3 months, the implants were restored with custom-made titanium abutments and cemented zirconia-based porcelain crowns. The clinical examination and radiograph data were assessed at restoration placement and after 12, 60, and 120 months. The patients answered a questionnaire to score their satisfaction before treatment and after 12, 60, and 120 months with the restoration in function. RESULTS: A total of 31 implants were placed. Implant survival was 100%. The 10-year mean marginal bone loss was 0.18 mm (SE: 0.08). The plaque, calculus, gingiva, and bleeding indices scores were low as was the mean pocket probing depth. The patients' satisfaction was high. CONCLUSION: The 10-year follow-up data of this limited case series study reveal that 6-mm dental implants inserted in the resorbed posterior mandible provide a solid basis for single tooth restorations.

Implants of 6 mm vs. 11 mm lengths in the posterior maxilla and mandible: a 1-year multicenter randomized controlled trial.

BACKGROUND AND AIM: In cases with limited bone height, short implants could be a good alternative to augmentation procedures. The aim of this randomized controlled trial was to compare the clinical performance of implants of 6 mm or 11 mm in length in the posterior region. MATERIALS AND METHODS: In this multicenter trial (six study sites), 95 subjects were included. Subjects were randomly allocated to receiving implants with lengths of either 6 or 11 mm both with a diameter of 4 mm (OsseoSpeed(™) 4.0 S; Astra Tech AB; Mölndal, Sweden). In all cases, there had to be sufficient bone height to allow placement of an implant of at least 11 mm in length. Two or three implants were placed per subject using one-stage surgery with a 42-48 days' healing period before loading. They were restored with a screw-retained splinted fixed prosthesis. Clinical and radiographic examinations were performed preoperatively, postsurgery, at loading, and 6 and 12 months after prosthesis placement. RESULTS: A total of 208 implants were inserted in 49 subjects receiving 6-mm implants (test) and in 46 subjects receiving 11 mm implants (control). Two 6-mm implants failed before loading and one 6 and 11 mm implants failed before 1-year evaluation. From loading to the 12 months' follow-up, a mean marginal bone gain of 0.06 mm in the 6 mm group and 0.02 mm in the 11 mm group was found (P = 0.478). Soft tissue behavior was equal in both groups (Bleeding and plaque [P = 1.0] probing depth [P = 0.91]). CONCLUSION: One-year data indicate that treatment with the 6 mm implants is as reliable as treatment with the 11 mm implants. This provides a good treatment option in situations with limited bone height in the premolar and molar regions. Whether or not short implants provide a predictable treatment alternative to bone augmentation procedures remains to be investigated in the future randomized controlled clinical trials.

Single implant-supported two-unit cantilever fixed partial dentures in the posterior region: a retrospective case series with a mean follow-up of 6.5 years.

BACKGROUND: The aim of this retrospective study was to evaluate the implant survival, clinical and radiographic outcomes, and patient satisfaction of single implant-supported two-unit cantilever fixed partial dentures in the posterior region. METHODS: Patients who received a single implant-supported fixed partial denture with a cantilever in the posterior region between January 2004 and February 2018 were included. Survival rate of the implants and the fixed partial dentures and data regarding the marginal bone level, presence of plaque, calculus, bleeding on probing, mucosa health, pocket probing depth, and patient satisfaction were collected during an evaluation visit. Complications were recorded from the medical records. RESULTS: Twenty-three patients (mean age 64 ± 13 years) with 28 implants could be included in the study. The mean follow-up period was 6.5 ± 4.8 years at the time of data collection. The survival rate of the implants and fixed partial dentures was 100%. Mean marginal bone loss for the mesial and distal side of the implants was 0.41 mm (SD 1.18 mm) and 0.63 mm (SD 0.98 mm) respectively. A high prevalence of peri-implant-mucositis (89.3%) and peri-implantitis (17.9%) was observed as well as a limited number of technical complications. Patients were quite satisfied, as reflected by a mean VAS score of 94.0 ± 7.2 points (range 0-100) and a OHIP-NL49 score of 10.8 (range 0-196). CONCLUSIONS: Single implant-supported fixed partial dentures with a mesial or distal cantilever can be a predictable treatment option in the posterior region, with stable peri-implant bone levels, minor technical complications, and very content patients. However, the prevalence of peri-implant mucositis and peri-implantitis was high. TRIAL REGISTRATION: ISRCTN, ISRCTN79055740 , Registered on March 14, 2021 - -Retrospectively registered.

Single crowns in the resorbed posterior maxilla supported by either 11-mm implants combined with sinus floor elevation or 6-mm implants:A 5-year randomised controlled trial.

PURPOSE: To assess the clinical performance of single crowns in the posterior maxilla supported by either 11-mm-long implants combined with maxillary sinus floor elevation surgery or 6-mm-long implants during a 5-year follow-up period. MATERIALS AND METHODS: A total of 38 consecutive patients, missing a premolar or a molar in the posterior maxilla and residual bone height underneath the maxillary sinus between 6 to 8 mm, were included. Subjects were randomly allocated to receive one 11-mm-long implant in combination with maxillary sinus floor augmentation or to receive one 6-mm-long implant without any grafting. A total of 41 implants (21 implants in 20 patients in the 6-mm group, and 20 implants in 18 patients in the 11-mm group) were placed and subsequently restored after 3 months with custom-made titanium abutments and cemented zirconia-based porcelain crowns. Both groups were followed by clinical (implant survival, restoration survival, complications, pocket probing depth and presence of plaque, calculus, bleeding and peri-implant inflammation) and radiographic examinations up to 5 years. The patient satisfaction was scored before treatment, and 12 and 60 months after functional implant restoration. RESULTS: One patient (11-mm group) died before the 12-month evaluation and one patient (6-mm group) moved away. In addition, one patient in the 6-mm group lost one implant and no implants were lost in the 11-mm group. Two patients lost three restorations in the 6-mm group and no restorations were lost in the 11-mm group. From loading until the 60-month assessment, the mean marginal bone loss in the 6-mm group and the 11-mm group was 0.12 ± 0.36 mm and 0.14 ± 0.63 mm, respectively, without a significant difference (mean difference 0.02 mm; 95% CI -0.32 to 0.37; P = 0.884). Implant loss, restoration loss, screw loosening and porcelain chipping were defined as complications. Four patients in the 6-mm group and one patient in the 11-mm group had one or more complications, without a significant difference between the groups (95% CI 0.019 to 0.244; P = 0.198). The patient satisfaction was high in both groups (mean overall satisfaction in the 6-mm and the 11-mm groups was 9.4 ± 0.8 and 9.2 ± 0.8, respectively; mean difference 0.2; 95% CI -0.33 to 0.76; P = 0.434). CONCLUSIONS: Reconstructions performed using an 11-mm implant combined with maxillary sinus floor augmentation or a 6-mm implant in the resorbed posterior maxilla are equally successful in supporting a single restoration over 5 years.

Single crown restorations supported by 6-mm implants in the resorbed posterior mandible: A five-year prospective case series.

PURPOSE: To assess clinical performance of single restorations supported by 6-mm long implants in the posterior mandible after 5 years in function. MATERIALS AND METHODS: Twenty-one consecutive patients with the absence of premolars or molars in the posterior mandible and an estimated bone volume of at least 6 mm in width and an estimated height of 8 mm between the top of the ridge and alveolar nerve were included. Each patient received one or more 6-mm implants. Custom-made titanium abutments with cemented zirconia-based porcelain crowns were placed after a 3-month osseointegration period. Data of clinical examinations and radiographs were assessed at placement of the restoration and 12 and 60 months thereafter. The patients answered a questionnaire to score the satisfaction before treatment and after 12 and 60 months with the restoration in function. RESULTS: Implant survival was 100%. Five-years' mean marginal bone loss was 0.14 mm (SD: 0.4). Indices scores for plaque, calculus, gingiva, and bleeding were low as well as mean pocket-probing depth. Patients' satisfaction was high. CONCLUSION: Five-year follow-up data of this limited case series study revealed that 6-mm dental implants inserted in the resorbed posterior mandible provide a solid basis for single tooth restoration.

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.

Single Restorations in the Resorbed Posterior Mandible Supported by 6-mm Implants: A 1-Year Prospective Case Series Study.

PURPOSE: The aim of this prospective case series study was to assess the clinical performance of single restorations in the posterior mandible supported by 6-mm implants. MATERIALS AND METHODS: Twenty-one consecutive patients with one or more missing premolars or molars in the posterior mandible and with an estimated bone height of 8 mm between the top of the ridge and alveolar nerve were included. Each patient was to receive one or more 6-mm implants (OsseoSpeed 4.0 S, Astra Tech Implant System, Dentsply Implants, Mölndal, Sweden) without any grafting. After a 3-month osseointegration period, the implants were restored with custom-made titanium abutments (Atlantis abutment, Dentsply Implants) and cemented zirconia-based porcelain crowns. Clinical and radiographic examinations were performed at placement of the restoration and 12 months thereafter. Next to this, patients' satisfaction was scored before treatment and after 12 months with the restoration in function. RESULTS: Implant survival was 100%. From loading to the 12-month follow-up, mean marginal bone loss was 0.14 mm (SD: 0.4). Mean scores for plaque, calculus, gingiva, bleeding, and pocket probing depth were low. Patients' satisfaction was high. CONCLUSION: One-year follow-up data revealed that 6-mm dental implants inserted in the resorbed posterior mandible provide a solid basis for single tooth restoration.

Single crowns in the resorbed posterior maxilla supported by either 6-mm implants or by 11-mm implants combined with sinus floor elevation surgery: a 1-year randomised controlled trial.

PURPOSE: The aim of this randomised controlled trial was to assess the clinical performance of single crowns in the posterior maxilla supported by either 6-mm or 11-mm implants combined with maxillary sinus floor elevation. MATERIALS AND METHODS: 41 consecutive patients with one missing premolar or molar in the posterior maxilla and with an estimated bone height of 6 to 8 mm in that area were included. Each patient was randomly allocated to one of the two treatment groups, namely to receive an 11-mm implant (Osseo Speed 4.0 S, Dentsply Implants, Mölndal, Sweden) in combination with maxillary sinus floor elevation surgery or to receive a 6-mm implant (Osseo Speed 4.0 S) without any grafting. After a 3-month osseointegration period, all implants were restored with custom-made titanium abutments and cemented zirconia-based porcelain crowns. Outcome measures were: implant survival; radiographic bone changes; plaque accumulation; bleeding tendency; peri-implant inflammation; presence of dental calculus; biological and technical complications; and patients' satisfaction. Clinical and radiographic examinations were performed at placement of the crown and 12 months thereafter. Patients' satisfaction was scored before treatment and after 12 months of functioning of the crown. RESULTS: One patient of the 11 mm implant group died during the follow-up. No implant failed and no biological or technical complications occurred. From loading to the 12 months follow-up, no difference was found in mean marginal bone changes between the groups (bone resorption in both groups 0.1 ± 0.3 mm). Clinical items revealed very healthy peri-implant soft tissues in both groups. Patients' satisfaction scores were high in both groups. CONCLUSIONS: 6-mm implants and 11-mm implants combined with sinus floor elevation surgery are equally successful to support a single crown in the resorbed posterior maxilla after 1-year follow-up.

Mandibular overdentures supported by 6-mm dental implants: a 1-year prospective cohort study.

BACKGROUND: The extremely resorbed edentulous mandible, with a bone height of 8 mm or less, is still a challenge in implant dentistry. Recently, dental implants of 6 mm in length have been developed. PURPOSE: The purpose of this 1-year prospective cohort study was to evaluate treatment outcome of mandibular overdentures supported by four 6-mm dental implants. MATERIALS AND METHODS: Twelve edentulous patients with a mandibular height between 6 and 8 mm participated. The patients were treated with an overdenture supported by four 6-mm OsseoSpeed dental implants (Astra Tech AB, Mölndal, Sweden). Clinical and radiographic parameters were evaluated 1 year after completion of the prosthetic treatment. Patients' satisfaction was scored before implant surgery and 1 year after prosthetic treatment. RESULTS: One-year implant survival rate was 96% (two implants were lost). One patient had a fracture of the mandible in the region of one of the implants 3 weeks after implant surgery. Mean scores for plaque, calculus, gingiva, bleeding, and pocket probing depth were low. Patients' satisfaction was high. CONCLUSION: One-year follow-up data revealed that four 6-mm dental implants inserted in an extremely resorbed edentulous mandible provided a solid basis for a bar-retained overdenture.