Classification Systems for Peri-implantitis: A Narrative Review with a Proposal of a New Evidence-Based Etiology Codification

PURPOSE

To present the different definitions of peri-implantitis proposed in the literature and to propose a new evidence-based etiology-driven classification of peri-implantitis to accurately and fully describe the etiology of peri-implantitis.

MATERIALS AND METHODS

Full-text papers on the selected topic were obtained for all abstracts and titles that appeared to meet the inclusion criteria. Additional papers were included from the reference lists of the selected studies. No methodologic and reporting quality of the included papers was applied in order to collect the greatest number of articles.

RESULTS

One hundred twenty-two studies were found according to the search criteria. After filter activation, abstract evaluation, and duplicate removal, 16 articles were deemed useful for the aim of the present narrative review. A manual search using personal contact and references of published works and contributions by the authors included another 16 articles, resulting in a total of 32 articles. After full-text article selection and reading, 15 articles were finally included.

CONCLUSION

There is not a generally accepted classification system of the various degrees of peri-implantitis. An etiology-driven classification was proposed as a tool to assist the clinician in properly detecting and classifying etiology-based peri-implantitis. This classification may also support the assignment of prognosis, and if needed, therapy to arrest/prevent peri-implantitis.

One-stage horizontal guided bone regeneration with autologous bone, anorganic bovine bone and collagen membranes: Follow-up of a prospective study 30 months after loading

PURPOSE

To present the medium-term results of one-stage guided bone regeneration (GBR) using autologous bone and anorganic bovine bone, placed in layers, in association with resorbable collagen membranes, for the reconstruction of horizontal bony defects.

MATERIALS AND METHODS

This study was designed as an uncontrolled prospective study. Partially edentulous patients, having less than 6.0 mm and more than 4.0 mm of residual horizontal bone width were selected and consecutively treated with simultaneously implant installation and bone regeneration by using 2.0 mm of autologous bone and 2.0 mm of anorganic bovine bone that was placed in layers and then covered with a resorbable collagen membrane. Outcome measures were: implant and prosthesis failures, any complications, peri-implant marginal bone level changes, probing pocket depth (PPD) and bleeding on probing (BOP).

RESULTS

In total, 45 consecutive patients (20 male, 25 female) with a mean age of 52.1 years each received at least one GBR procedure, with contemporary placement of 63 implants. At the 3-year follow-up examination, no patient had dropped out and no deviation from the original protocol had occurred. No implant or prosthesis failed. In six patients (13.3%) the collagen membrane was slightly exposed 1 to 2 weeks after bone reconstruction. Four of these patients were moderate smokers. Post-hoc analysis using Fisher's exact test found significant association (P = 0.0139) between a smoking habit and early membrane exposure. Mean marginal bone loss experienced between initial loading and 30 months afterwards was 0.60 ± 0.20 mm (95% CI 0.54 - 0.66). The mean BOP values measured at the definitive restoration delivery were 1.23 ± 0.93, while 2 years later they were 1.17 ± 0.78. The difference was not statistically significant (-0.06 ± 0.76; P = 0.569). The mean PPD values measured at the definitive restoration delivery were 2.62 ± 0.59 mm, while 2 years later they were 2.60 ± 0.54 mm. The difference was not statistically significant (-0.03 ± 0.62; P = 0.765).

CONCLUSIONS

Within the limitations of the present study, the use of a 2.0 mm layer of particulated autologous bone on the implant threads, and a 2.0 mm layer of anorganic bovine to cover the resorbed ridge, in combination with the resorbable collagen membrane, seems to be a viable treatment option for the reconstruction of horizontal bony defects.

1-year results from a split-mouth randomised controlled pilot trial comparing implants with 0.75 mm of machined collar placed at bone level or supracrestally

PURPOSE

The present study evaluated the hypothesis that implants inserted at bone level or supracrestally have different outcomes in single tooth replacements against the alternative hypothesis of no difference.

MATERIALS AND METHODS

This study was designed as a randomised, split-mouth, controlled pilot trial. Ten patients, each missing two bicuspids or molars, were treated with 20 implants featuring 0.75 mm of machined collar. Each patient randomly received one implant inserted at bone level (BL) and one inserted 0.75 mm to 1 mm above the alveolar crest (SC), measured with a periodontal probe during surgery. All the implants were inserted into healed healthy bone with an insertion torque ranging between 35 Ncm and 45 Ncm. Both implants were loaded with screw-retained acrylic-resin temporary crowns 3 months after implant insertion and 3 months later with screw-retained zirconia-ceramic definitive crowns. Outcome measures were implant/crown failures, biological and prosthetic complications, radiographic marginal bone level changes (MBL), probing pocket depth (PPD) and bleeding on probing (BOP). Clinical data were collected at baseline (implant insertion) and 1 year after implant placement (9 months after initial loading).

RESULTS

After 1 year of follow-up, no patients dropped out, no implants failed, and no complications occurred. The mean MBL at the 1-year follow-up was 0.28 ± 0.21 mm in the SC group and 0.93 ± 0.37 mm in the BL group. While the difference in MBL was statistically significant between the two treatment groups (difference 0.65 ± 0.34; 95% CI = 0.59 to 1.01; P = 0.0001), the soft-tissue parameters were not statistically different. The mean PPD was 2.63 ± 2.4 in the SC group and 2.40 ± 0.70 in the BL group (P = 0.419) and mean BOP was 0.50 ± 0.71 in the SC group and 0.40 ± 0.70 in the BL group (P = 0.754).

CONCLUSIONS

The smooth-collar implants inserted supracrestally showed 0.7 mm less radiographic marginal bone loss compared with implants inserted at the bone level 9 months after loading.

Computer-guided vs freehand placement of immediately loaded dental implants: 5-year postloading results of a randomised controlled trial

PURPOSE

To compare planning and patient rehabilitation using 3D implant planning software and dedicated surgical templates with conventional freehand implant placement for the rehabilitation of partially or fully edentulous patients using flapless or mini-flap procedures and immediate loading.

MATERIALS AND METHODS

Patients requiring at least two implants to be restored with a single prosthesis, having at least 7 mm of bone height and 4 mm in bone width were consecutively enrolled. Patients were randomised according to a parallel group study design into two groups: computerguided group or conventional freehand group. Implants were loaded immediately with a provisional prosthesis, replaced by a definitive prosthesis 4 months later. Outcome measures assessed by a blinded independent assessor were: implant and prosthesis failures, any complications, marginal bone levels, number of treatment sessions, duration of treatment, post-surgical pain and swelling, consumption of pain killers, surgical and prosthetic time, time required to solve complications, and patient satisfaction. Patients were followed up to 5 years after loading.

RESULTS

Ten patients (32 implants) were randomised to the computer-guided group and 10 patients (30 implants) were randomised to the freehand group. At the 5-year follow-up examination one patient of the computer-guided group and one of the freehand group dropped-out (both moved to another country). No prostheses failed during the entire follow-up. Two implants failed in the conventional group (6.6%) vs none in the computer-guided group (P = 0.158). Ten patients (five in each group) experienced 11 complications (six in the computer-guided group and five in the freehand group), that were successfully solved. Differences between groups for implant failures and complications were not statistically significant. Five years after loading, the mean marginal bone loss was 0.87 mm ± 0.40 (95% CI: 0.54 to 1.06 mm) in the computer-guided group and 1.29 mm ± 0.31 (95% CI: 1.09 to 1.51 mm) in the freehand group. The difference was statistically significant (difference 0.42 mm ± 0.54; 95% CI: 0.05 to 0.75; P = 0.024). Patient self-reported post-surgical pain (P = 0.037) and swelling (P = 0.007) were found to be statistically significant higher in patients in the freehand group. Number of sessions from patient's recruitment to delivery of the definitive prosthesis, number of days from the initial CBCT scan to implant placement, consumption of painkillers, averaged surgical, prosthetic, and complication times, were not statistically significant different between the groups. At the 5-year followup, all the patients were fully satisfied with the function and aesthetics of their definitive prostheses.

CONCLUSIONS

Both approaches achieved successful results over the 5-year follow-up period. Statistically higher post-operative pain and swelling were experienced at sites treated freehand with flap elevation. Less marginal bone loss (0.4 mm) was observed in the computer-guided group, at 5 years follow-up.

Immediate non-occlusal versus delayed loading of mandibular first molars. Five-year results from a randomised controlled trial

PURPOSE

To compare outcomes of immediate non-occlusal loading with delayed implant loading in the bilateral replacement of mandibular first molars.

MATERIALS AND METHODS

This study was designed as a split-mouth, randomised controlled trial. Twenty patients with bilaterally missing mandibular first molars randomly received immediately or conventionally loaded single implants. One molar was restored with a non-occlusal temporary crown within 24 hours after implant placement (immediate loading group, IL) while the contralateral molar was restored with a definitive crown 4 to 5 months later (delayed loading group, DL). A total of 40 implants were installed. All implants were inserted in healed bone with an insertion torque between 35 and 45 Ncm. Outcome measures were implant failure, complications, radiographic marginal bone level changes, probing pocket depths (PPDs) and bleeding on probing (BOP). Clinical data were collected at implant placement, and after 6, 12 and 60 months.

RESULTS

No patients dropped out and no implant failed. Only minor prosthetic complications were observed (two provisional acrylic crown fractures in the IL group and four ceramic chipping in the DL group). Two patients had bilateral peri-implant mucosal inflammation with BOP after 6 months. The differences between groups were not statistically significant (OR = 0.500; 95% CI: 0.045 to 3.489; P = 0.6831). At the 1-year follow-up examination, the mean marginal bone level was 0.83 ± 0.16 mm (95% CI: 0.75 to 0.91) in the IL group and 0.86 ± 0.16 mm (95% CI: 0.78 to 0.94) in the DL group, with no statistically significant differences between groups (difference = 0.03 ± 0.15 mm; 95% CI: -0.07 to 0.07; P = 0.53). After 5 years, mean marginal bone level was 1.06 ± 0.38 mm (95% CI: 0.97 to 1.15) in the IL group and 1.07 ± 0.32 mm (95% CI: 0.95 to 1.16) in the DL group, with no statistically significant differences between groups (difference = 0.01 ± 0.22 mm; 95% CI: -0.10 to 0.10; P = 0.96). The mean marginal bone loss after 5 years was 0.62 ± 0.45 mm in the IL group and 0.69 ± 0.33 mm in the DL group (difference = 0.07 ± 0.32 mm; 95% CI: -0.10 to 0.18; P = 0.567). At the 5-year follow-up the mean PPD and BOP values were 2.82 ± 0.65 mm and 1.17 ± 0.92 in the IL group, and 2.85 ± 0.53 mm and 1.17 ± 0.86 in the DL group, respectively. No significant differences were found (difference = 0.03 ± 0.15 mm; 95% CI: -0.15 to 0.21; P = 0.990; and 0.01 ± 0.07; 95% CI: -0.06 to 0.08; P = 1.000, respectively).

CONCLUSIONS

Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of immediate versus delayed loading of implants in mandibular fist molar sites is comparable.

Minimally Invasive Sinus Augmentation Procedure Using a Dedicated Hydraulic Sinus Lift Implant Device: A Prospective Case Series Study on Clinical, Radiologic, and Patient-Centered Outcomes

The aim of this study was to evaluate clinical and radiologic outcomes of a novel device that allows simultaneous hydraulic sinus membrane elevation, bone grafting, and implant placement. A sample of 18 consecutive participants with severe atrophy of the posterior maxilla underwent transcrestal elevation of the sinus membrane and implant placement. At the 6-month follow-up, the following parameters were assessed: implant success, any complications, marginal bone loss (MBL), three-dimensional (3D) graft measurements, implant stability quotient (ISQ), and graft density. No implants failed during follow-up (10.8 ± 2.8 months; range: 7-14 months). No membrane tears or other adverse events were observed. Mean residual alveolar ridge height was 4.78 ± 0.88 mm. Six months after the procedure, the mean MBL was 0.18 mm. The mean sinus membrane elevation was 12.78 ± 2.18 mm (range: 10.7-14.23). Along the basic 3D reference planes, the dimensions of grafted bone measured around implants were as follows: axial area = 239.7 ± 57.68 mm²; sagittal area = 257.0 ± 60.83 mm²; coronal area = 143.3 ± 29.46 mm². The mean volume of the graft was 2.38 ± 0.26 mL at baseline and 2.05 ± 0.24 mL 6 months after graft maturation (difference: 0.33 ± 0.29 mL, P = .0090). Graft density (in Hounsfield units [HU]), improved during healing from 322.0 ± 100.42 HU to 1,062.0 ± 293.7 HU; difference 740.0 ± 295.35 HU (P = .0001). The mean ISQ value was 65.5 at implant placement, and it increased to 74.1 at the 6-month examination (P = .0014). Of 18 patients, 12 experienced no pain (66.6%) and 10 experienced no swelling (55.5%). No severe pain or swelling was reported in any of the cases. The mean number of analgesic tablets consumed was 0.78 ± 0.67. Mean surgical time was 24.0 ± 4.07 minutes. The iRaise Sinus Lift System may provide a new option for minimally invasive transcrestal sinus surgery with minimal patient discomfort. A physiologic contraction of 13.9% of its original volume was experienced during healing. Long-term clinical studies are needed to confirm these preliminary results.

Definitive Abutments Placed at Implant Insertion and Never Removed: Is It an Effective Approach? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

To assess whether repeated abutment disconnections and reconnections have any impact on peri-implant bone resorption and soft tissue healing.

MATERIALS AND METHODS

Electronic and manual searches were conducted for English-language articles published up to March 2017 that identified a relation between repeated disconnections of implant abutments (PA group) and prosthetic or implant failures, complications, marginal bone loss (MBL), soft tissue healing, and esthetic evaluation (pink esthetic score [PES]) after at least 1 year of function compared with implants receiving a final abutment at the time of implant placement (DA group).

RESULTS

Fourteen articles (535 patients with 994 implants) were selected for qualitative analysis. Six of these were included in the meta-analysis. Five prostheses failed in the PA group and 1 failed in the DA group (P = .1047). Seven biologic complications occurred in the PA group and 6 occurred in the DA group (P = .8121). MBL was significantly less in the DA group (difference, 0.279 mm; P = .000). Greater buccal recession occurred in the PA group (difference, 0.198 mm; P = .0004). The PES evaluation showed no differences between groups (P = .289).

CONCLUSIONS

Repeated abutment disconnections and reconnections considerably increased MBL and buccal recession. Further studies are needed to confirm these results.

Mucosa Thickness and Peri-implant Crestal Bone Stability: A Clinical and Histologic Prospective Cohort Trial

PURPOSE

To correlate soft tissue thickness and peri-implant bone remodeling of platform-switching implants.

MATERIALS AND METHODS

This comparative prospective trial evaluated, for up to 3 years after implant loading, the influence of soft tissue thickness on changes in peri-implant marginal hard tissue levels. Any patient who was partially edentate in the mandible and required at least two adjacent implant-supported restorations was recruited at the University of Valencia in Spain. A 3-mm tissue punch biopsy, which corresponded to a diameter slightly smaller than the coronal diameter of the implants, was performed using a circular mucotome. Afterward, implants with a length of 10 to 13 mm and a diameter of 3.8 mm were inserted. Outcome measures were implant and prosthesis survival rates, marginal hard tissue changes, any complications, and results of morphologic and histomorphometric analyses. Correlation between mucosa width components (epithelium, connective tissue, and epithelium and connective tissue) and radiographic bone loss at 1 and 3 years after loading was performed at the patient level. Statistical significance was set at P ≤ .05.

RESULTS

A total of 26 samples in 26 patients with 68 implants were analyzed. The specimens were divided into two groups: group 1 (16 patients, 40 implants), with thin mucosa (≤ 2 mm), and group 2 (10 patients, 28 implants), with thick mucosa (> 2 mm). Two dropouts (two specimens) were recorded at the 3-year follow-up. None of the implants or definitive prostheses failed during the healing period, resulting in an overall implant and prosthesis cumulative survival rate of 100%. No major biologic or mechanical complications were recorded. The mean (standard deviation, SD) epithelium thickness was 430.33 (250.21) μm; the mean (SD) connective tissue thickness was 1,324.31 (653.46) μm, and the mean (SD) mucosa thickness was 1,751.29 (759.53) μm. Comparisons of radiographic bone loss between group 1 and group 2 failed to show any statistically significant differences at the 1-year (P = .290) or 3-year (P = .090) follow-up examinations.

CONCLUSION

The initial mucosa thickness surrounding a bone-level platform-switching implant seems not to influence the pattern of physiologic marginal bone loss.

Vertiginous crisis following temporomandibular joint athrocentesis: a case report

Temporomandibular joint arthrocentesis and arthroscopy have recently exceeded open surgeries for disorders that failed to respond to conservative treatment. The efficacy of arthrocentesis in reestablishing normal mouth opening and reducing pain and dysfunctions is now commonly accepted, but in contrast to arthroscopy, there are no large series studies on arthrocentesis complications. We report the major complication occurred in our experience: a case of a patient that complained of a violent vertigo, without hearing disorders, following the procedure.

Aesthetic and Functional Evaluation of Total Nasal Reconstructions

The loss of a portion or the totality of the nose has great relevance on the perception of the beauty of a face and can result in a catastrophic quality of life impairment. Several surgical techniques are currently available for the reconstruction of the nasal pyramid. However, there are very few nasal reconstruction quality evaluation protocols that allow the surgeon to choose objectively the best technique for each kind of defects. Six total nasal reconstruction performed in University of Sassari Maxillofacial Unit were evaluated with a protocol that investigate objectively and subjectively the surgical aesthetic and functional outcome. Sensitivity recovery on the reconstructive flaps was also assessed. Patients reported a satisfactory nasal reconstruction both functionally and aesthetically. Sensitivity recovery on the forehead flap was always present even after pedicle resection or in case of traumatic section of the infraorbital nerve. The use of a three layer reconstruction has proved a viable technique both aesthetically and functionally. In particular the use of the forehead flap to reconstruct the outer layer of the nose allows to carry a tissue with very similar characteristics to the original with a recovery of the sensitivity almost complete.

Crestal sinus lift using an implant with an internal L-shaped channel: 1-year after loading results from a prospective cohort study

PURPOSE

To evaluate the clinical and radiographic outcomes of a one-stage crestal sinus elevation procedure using a self-tapping endosseous implant system (iRaise, Maxillent, Herzliya, Israel) developed for sinus augmentation, 1 year after loading.

MATERIALS AND METHODS

Patients needing restoration in the posterior maxilla with a residual alveolar crest of 3 to 8 mm in height and 5 mm in width distal to the canine as measured on CBCT scan were treated using the iRaise sinus lift system. Outcome measures were: implant and prosthetic failures, any complications, increased bone height (iBH), marginal bone loss (MBL), implant stability quotient (ISQ), radiographic tissue remodelling patterns using the sinus grafting remodelling index (SGRI), volumetric measurements of sinus graft, patient self-reported post-surgical swelling, consumption of pain medication and histological analysis.

RESULTS

A total of 30 consecutive participants with a mean age of 54.2 ± 9.4 years underwent a transcrestal elevation of the sinus membrane, insertion of bone graft, and implant placement. A total of 50 implants were placed (30 iRaise system implants and 20 adjunctive iSure implants, Maxillent). The mean follow-up was 15.8 ± 2.1 months after implant loading. One patient dropped out at the 1-year after loading follow-up examination. No implants and no prostheses failed during the entire follow-up. One patient experienced a small membrane tear. Before implant insertion, the mean residual alveolar ridge height was 4.64 ± 0.86 mm (range: 3.4-6.4 mm; 95% CI: 4.39-5.01 mm). One year after loading, the bone height was 16.86 ± 3.13 mm (95% CI 15.83-18.07 mm). At the 1-year after loading follow-up, the mean MBL was 0.19 ± 1.05 mm (95% CI 0.02-0.78 mm). The mean ISQ at implant placement was 65.2 ± 5.4 (95% CI 63.6-67.4) and increased during the healing period reaching the mean value of 73.6 ± 3.7 (95% CI 73.1-75.9; range 62-79). The difference was statistically significant (8.4 ± 5.3; 95% CI 5.9-39.7; P = 0.0000). One year after loading, SGRI score was evaluated in 23 implants. Overall, the mean SGRI value was 2.29 ± 2.41 mm (95% CI 1.22-2.98 mm). Bone volume at implant placement was 2.41 ± 0.25 CC (95% CI 2.22-2.48 CC). During the 6-month, submerged healing period, a slight bone contraction of 11.3% were observed. (2.13 ± 0.24 CC;95% CI 2.02-2.26; difference = 0.27 ± 0.25 CC; 95% CI 0.10-0.36; P = 0.0011). At the first year post-loading period, the bone graft remained stable (2.11 ± 0.22 CC; 95% CI 2.02-2.24). The difference was not statistically significant (0.02 ± 0.07 CC; 95% CI 0.01-0.04; P = 0.2166). From the patient's point of view, the mean pain value was 0.52 ± 0.74 (range 0-3); mean swelling value was 0.27 ± 0.52 (range 0-2); and the mean consumption of analgesic was 0.87 ± 4.94 tablets (range 0-4) 3 days after surgery. Morphological and histomorphometric analyses showed that all the samples had a normal structure without inflammatory infiltrate, six months after healing. The following fractions (%) were found: bone (immature bone + mature bone): 44.07 ± 4.91; residual biomaterial: 23.98 ± 2.64; medullary spaces: 31.95 ± 3.16.

CONCLUSIONS

Sinus floor augmentation can be successfully accomplished with a transcrestal approach using a dedicated implant system. A physiologic contraction of 11.3% of the original volume of the bone graft was experienced during the first 6 months of healing; afterwards, no additional graft volume reduction was observed. Long-term clinical studies are needed to confirm these preliminary results.

Molar replacement with 7 mm-wide diameter implants: to place the implant immediately or to wait 4 months after socket preservation? 1 year after loading results from a randomised controlled trial

PURPOSE

To test the hypothesis that there is no difference in clinical, radiographic and aesthetic outcomes positioning single post-extractive 7 mm-diameter implants or waiting 4 months after molar extraction and socket preservation procedure.

MATERIAL AND METHODS

Patients requiring one implant-supported single restoration to replace a failing tooth in the molar region of both maxilla and mandible were selected. Patients were randomised according to a parallel group design into two arms: implant installation in fresh extraction sockets grafted with cortico-cancellous heterologous bone and porcine derma (group A) or delayed implant installation 4 months after tooth extraction and socket preservation using the same materials (group B). Implants were submerged for 4 months. The primary outcome measures were the success rates of the implants and prostheses and the occurrence of any surgical and prosthetic complications during the entire follow-up. Secondary outcome measures were: peri-implant marginal bone level (MBL) changes, resonance frequency analysis (ISQ) and pink esthetic score (PES) values at implant placement (baseline) up to 1 year after loading.

RESULTS

Twelve patients were randomised to group A and 12 to group B. No patient dropped out within 1 year after loading. No implant and prosthesis failed and no complications occurred during the entire follow-up. One year after loading, statistically significant higher mean MBL loss was experienced in group A (0.63 mm ± 0.31 mm) compared to group B (0.23 mm ± 0.06 mm); difference 0.41 mm (95% CI 0.17-0.53; P = 0.001). Six months after implant placement, mean ISQ value was 78.8 ± 2.8 for group A and 79.9 ± 3.6 for group B, showing no statistically significant difference between groups (difference 1.1; 95% CI: 0.04 to 2.96; P = 0.422). One year after loading, mean PES was 10.6 ± 1.8 [range: 8 to13] in group A and 12.2 ± 1.2 [range: 11 to 14] in group B. The difference was statistically significant (1.6 ± 2.7; 95% CI -0.55-2.55; P = 0.019) with better results for group B.

CONCLUSIONS

Within the limitations of this study, both procedures achieved successful results over the 1-year follow-up period, but waiting 4 months after tooth extraction and socket preservation procedure was associated with less marginal bone loss and a better aesthetic outcome. Conflict-of-interest statement: Dr Marco Tallarico is Research Project Manager of Osstem AIC Italy. However no company supported this study and all authors declare no conflicts of interest.

Sinus lift grafting with anorganic bovine bone vs 50% autologous bone mixed with 50% anorganic bovine bone: 2 years after loading results from a randomised controlled trial

PURPOSE

To compare the outcome of implants inserted in maxillary sinuses augmented with anorganic bovine bone (ABB) grafts vs mixed 50% ABB and 50% autologous bone graft, using a lateral window approach.

MATERIALS AND METHODS

This study was designed as a randomised controlled trial of parallel groups. Patients in need of an implant-supported prosthesis in a maxillary posterior area with a residual alveolar bone height no greater than 4 mm (range 0-4 mm) were recruited for lateral sinus grafting. Patients were randomly allocated to receive 50% ABB and 50% autogenous bone (group A) or 100% ABB (group B). After 7 months, tapered implants were inserted with an insertion torque between 20 and 45 Ncm. After 3 months, implants were loaded with screw-retained temporary crowns. Definitive crowns were delivered 3 months later. Outcome measures were implant survival, complications, radiographic marginal bone-level changes, probing pocket depths (PPD) and bleeding on probing (BOP). Clinical data were collected at definitive prosthesis delivery, 1 and 2 years after loading.

RESULTS

Thirty-two consecutive patients were treated with 32 sinus lift procedures (16 group A, 16 group B). A total of 46 implants were installed. No patient dropped out. No crown/implant failed by the end of the study. Three complications (one sinus membrane perforation and two chipping of the ceramic) were observed in three patients in group A, vs none in group B (RR 0.81; 95% CI 0.64 - 1.03 mm; P = 0.225). At the 2-year after final loading follow-up, the mean marginal bone loss was 1.18 ± 0.50 mm (95% CI 0.95 - 1.45 mm) in group A and 1.28 ± 0.48 mm (95% CI 0.97 - 1.43 mm) in group B, with no statistically significant differences between the two groups (difference 0.11 ± 0.22 mm; 95% CI -0.06 - 0.16 mm; P = 0.586). At the same follow-up, the mean PPD value was 2.70 ± 0.39 for group A and 2.54 ± 0.66 for group B, with no statistically significant difference between groups (difference 0.17 ± 0.39 mm; 95% CI 0.06 - 0.32 mm; P = 0.456), while the mean BOP value was 1.21 ± 0.79 for group A and 1.28 ± 0.68 for group B, (difference: 0.06 ± 0.49 mm; 95% CI -0.23 - 0.25 mm; P = 0.297).

CONCLUSIONS

Within the limitations of this study, the present data seem to confirm the hypothesis that the clinical outcome of implants inserted in sinuses grafted with ABB vs implants inserted in sinuses grafted with mixed 50% ABB and 50% autologous bone are comparable. Conflict-of-interest statement: This study was not supported by any company. All the authors declare no conflict of interest.

A novel implant system dedicate to hydraulic Schneiderian membrane elevation and simultaneously bone graft augmentation: An up-to 45 months retrospective clinical study

PURPOSE

To evaluate clinical and radiographic performance of a novel implant system that allows for hydraulic Schneiderian membrane elevation and simultaneously bone graft augmentation.

MATERIALS AND METHODS

Sixty-two consecutive patients with a mean age of 53.1 years and a severe atrophy of the posterior maxilla (3.0 to 7.0 mm) underwent 64 transcrestal sinus floor elevations and submerged implant placement. The following clinical and radiographic parameters were assessed: implant failure, any complications and bone gain measured using cone beam computed tomography.

RESULTS

No patient dropped out. No implants failed and all the prostheses were uneventful at the last follow-up examination (mean 23.0 months; range 12-45). All the procedures were completed successfully, with elevation of the sinus membrane and insertion of bone graft and the dental implant at the planned site. No intraoperative or postoperative adverse events were observed, such as membrane tears or facial hematoma. The mean residual alveolar ridge height was 5.2 ± 1 mm (range 3.3-7.0 mm). Mean bone gain was 10.9 ± 2.43 mm (range 5.3-16.5) after an average healing period of 8 months.

CONCLUSIONS

Hydraulic elevation of the Schneiderian membrane using the iRaise sinus-lift system (Maxillent Ltd) can be considered a valuable treatment option for the rehabilitation of atrophic edentulous posterior maxillae.

Single post-extractive ultra-wide 7 mm-diameter implants versus implants placed in molar healed sites after socket preservation for molar replacement: 6-month post-loading results from a randomised controlled trial

PURPOSE

To test the hypothesis that there is no difference in clinical, radiographic and aesthetic outcomes positioning single post-extractive ultra-wide 7 mm-diameter implants or waiting 4 months to place implant, after molar extraction and the socket preservation procedure.

MATERIAL AND METHODS

Patients requiring one implant-supported single restoration to replace a failed tooth in the molar region of both maxilla and mandible were selected. Patients were randomised according to a parallel group design into two arms: implant installation in fresh extraction sockets augmented with corticocancellous heterologous bone and porcine derma (group A) or delayed implant installation 4 months after tooth extraction and socket preservation using the same materials (group B). Ultra-wide 7 mm-diameter implants were submerged for 4 months. Outcome measures were implant success and survival; complications; horizontal dimensional changes measured on cone beam computed tomography (CBCT) scans at three levels, localised 1, 2 and 3 mm below the most coronal aspect of the bone crest (level A, B and C); peri-implant marginal bone level changes; implant stability quotient (ISQ); and pink esthetic score (PES).

RESULTS

Twelve patients were randomised to group A and 12 to group B. No patients dropped out. No implant failed or complications occurred up to 6-months post-loading. Six months after loading there was more horizontal alveolar bone reduction at immediate post-extractive implants, which was statistically significant. At level A was 1.78 mm ± 1.30 in group A, 0.45 mm ± 0.42 in group B, (difference 1.33 mm ± 1.39; 95% CI: 0.38 to 1.95; P = 0.003); at level B was 0.98 mm ± 1.13 in group A, 0.14 mm ± 0.22 in group B, (difference 0.84 mm ± 1.16; 95% CI: 0.24 to 1.07; P = 0.019); at level C was 0.55 mm ± 0.74 in group A, 0.03 mm ± 0.24 in group B, (difference 0.51 mm ± 0.76, 95% CI: 0.01 to 0.87; P = 0.032). One year after implant placement, mean peri-implant marginal bone loss was 0.43 mm ± 0.37 for group A and 0.10 mm ± 0.10 for group B, showing a statistically significant difference between groups (difference 0.33 mm ± 0.30; 95% CI: 18 to 0.52; P = 0.010). Mean ISQ value was 78.8 ± 2.8 for group A and 79.9 ± 3.6 for group B, showing no statistically significant differences between groups (difference 1.1 ± 2.6; 95% CI: 0.04 to 2.96; P = 0.422). Mean PES was similar in both groups (10.7 ± 1.5 [range: 8 to 13] in group A and 11.7 ± 1.2 [range: 10 to 13] in group B; difference 1.0 ± 2.2; 95% CI: -0.23 to 2.23; P = 0.081).

CONCLUSIONS

Single post-extractive ultra-wide 7 mm-diameter implants, in combination with socket preservation, might be a possible strategy in the replacement of hopeless molars in both jaws, with high implant and prosthetic survival and success rates, and good aesthetic outcomes. Longer follow-ups are needed to properly evaluate this therapeutic option. Conflict-of-interest statement: Dr Marco Tallarico is Research and Scientific Project Manager of Osstem AIC Italy. However, this study was not supported by any company and all authors declare no conflicts of interest.

Platform switching versus regular platform implants: 3-year post-loading results from a randomised controlled trial

PURPOSE

To test the hypothesis that platform switching and regular platform implants would have different outcomes in single-tooth replacement against the alternative hypothesis of no difference.

MATERIAL AND METHODS

This study was designed as a randomised controlled split-mouth trial. Eighteen patients with bilaterally missing single premolars or molars to be restored with implant-supported single crowns, were consecutively enrolled. Implant sites were randomly assigned to be treated according to the platform switching concept (PS group), or with matching implant-abutment diameters (RP group). A total of 36 Nobel Replace Tapered Groovy implants were installed. All the implants were inserted in healed bone, with an insertion torque between 35 and 45 Ncm, according to a one-stage protocol. Both implant types were loaded with a screw-retained temporary crown 3 months after implant insertion. Definitive screw-retained single crowns were delivered 2 months later. Outcome measures were implant and prosthetic survival rates, biological and prosthetic complications, radiographic marginal bone level (MBL) changes, pocket probing depth (PPD) and bleeding on probing (BOP). Clinical data was collected at implant placement (baseline), and at 3, 9 and 36 months after loading.

RESULTS

No patients dropped out and no implant failed. No prosthetic complications were recorded. One patient experienced mucosal inflammation with positive BOP (RP group) after 3 months, three patients had bilateral peri-implant mucosal inflammation with positive BOP at 6, 24 and 30 months after loading, respectively. There were no statistically significant differences between groups for complications (3/18 versus 4/18; P = 1.0; Odds Ratio = 1.333; 95% CI: 0.3467 to 5.1272). Nine months after loading, the mean MBL was 0.93 ± 0.26 mm in the RP group and 0.84 ± 0.23 mm in the PS group, with no statistically significant differences between groups (mean difference = 0.09 mm, 95% CI: -0.22 to 0.04, P = 0.18). Three years after loading, mean MBL was 1.09 ± 0.31 mm in the RP group and 1.06 ± 0.24 mm in the PS group, with no statistically significant differences between groups (mean difference = 0.02 mm, 95% CI: -0.06 to 0.10, P = 0.70). Marginal bone level changes between 3 years and baseline were 0.72 ± 0.28 mm in the RP group and 0.71 ± 0.27 mm in the PS group, with no statistically significant differences between the groups (mean difference = -0.00 mm, 95% CI: -0.07 to 0.07, P = 0.89). Mean PPD was 2.70 ± 0.52 mm in the RP group and 2.46 ± 0.69 mm in the PS group at 36 months after loading, with no statistically significant differences between the groups (mean difference = 0.23 mm, 95% CI: -0.05 to 0.35, P = 0.43). Mean BOP was 0.83 ± 0.96 mm in the RP group and 0.89 ± 0.99 mm in the PS group at 36 months after loading, with no statistically significant differences between the groups (mean difference = 0.07 mm, 95% CI: -0.03 to 0.17, P = 0.77).
 Conclusions: The clinical and radiographic outcomes of implants restored according to the platform-switching concept versus implants restored with the matching implant-abutment diameters are comparable, 3 years after loading. Conflict of interest statement: This study was not supported by any company. All authors declare no conflict of interest.