European Journal of Oral Implantology最新文献

Aim: The use of intraoral scanners (IOS) for making digital implant impressions is increasing. However, there is a lack of evidence on the accuracy of IOS compared with conventional techniques. Therefore, the aim of this systematic review was to collect evidence on the accuracy of digital implant impression techniques, as well as to identify the main factors influencing the accuracy outcomes.

Materials and methods: Two reviewers searched electronic databases in November, 2016. Controlled vocabulary, free-text terms, and defined inclusion and exclusion criteria were used. Publications in English language evaluating the accuracy outcomes of digital implant impressions were identified. Pooled data were analysed qualitatively and pertinent data extracted.

Results: In total, 16 studies fulfilled the inclusion criteria: one in vivo and 15 in vitro studies. The clinical study concluded that angular and distance errors were too large to be acceptable clinically. Less accurate findings were reported by several in vitro studies as well. However, all in vitro studies investigating the accuracy of newer generation IOS indicated equal or even better results compared with the conventional techniques. Data related to the influence of distance and angulation between implants, depth of placement, type of scanner, scanning strategy, characteristics of scanbody and reference scanner, operator experience, etc were analysed and summarised. Linear deviations (means) of IOS used in in vitro studies ranged from 6 to 337 µm. Recent studies indicated small angle deviations (0.07-0.3°) with digital impressions. Some studies reported that digital implant impression accuracy was influenced by implant angulation, distance between the implants, implant placement depth and operator experience.

Conclusions: According to the results of this systematic review and based on mainly in vitro studies, digital implant impressions offer a valid alternative to conventional impressions for single- and multi-unit implant-supported restorations. Further in vivo studies are needed to substantiate the use of currently available IOS, identify factors potentially affecting accuracy and define clinical indications for specific type of IOS. Data on Data on accuracy OF digital records, as well as accuracy of printed or milled models for implant-supported restorations, are of high relevance and are still lacking. Conflict-of-interest and funding statement: The authors state there is no conflict of interest.

Purpose: To examine differences in morphology and in immunophenotype subsets between chronic periodontitis (CP) and peri-implantitis (P-I) lesions and to test the diagnostic agreement (CP vs P-I) among three independent observers, based on histopathological features.

Materials and methods: This observational cross-sectional study included 15 gingival biopsies of CP lesions and 15 biopsies of P-I lesions for double-blinded examination by three independent pathologists. Inflammatory infiltrate intensity was assessed semiquantitatively on a 4-point scale, determining the percentage of lymphocytes, plasma cells, monocytes/macrophages, and granulocytes and the presence/absence of bacterial colonies. Immunohistochemical analyses were performed to verify the inflammatory infiltrate subset data (CD45, CD38, CD68 and myeloperoxidase [MPO]-positive), and number of vessels. Kappa statistic was used to evaluate the degree of diagnostic concordance among examiners.

Results: Inflammatory infiltrate was significantly more severe in P-I cases (P = 0.01), which showed a significantly higher percentage of plasma cells (P = 0.004) than in CP cases. Immunohistochemically, the percentage of leukocyte subsets was generally lower in CP (CD38: 32.05%; CD68: 6.45% and MPO: 8.62%) than in P-I (CD38: 61.13%; CD68: 9.09% and MPO: 7.47%) (CD38 P = 0.001, P = 0.955 and P = 0.463, for remaining subsets, respectively; Mann-Whitney U-test). The inter-observer diagnostic agreement was poor or slight (kappa = -0.18 to 0.13).

Conclusions: Despite the significantly more severe general inflammatory infiltrate and plasma cells in P-I cases, it proved difficult to detect reliable differential morphological features based on histopathological images of these CP and P-I soft-tissue samples, obtaining low inter-observer and intra-observer diagnostic agreement. Conflict of interest statement: This investigation was partially supported by Research Groups #CTS-138 and #CTS-583 (Junta de Andalucía, Spain). No conflict of interest.

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.

Purpose: To evaluate the clinical outcome of four to five implants immediately restored with metal-resin screw-retained cross-arch fixed prostheses in edentulous jaws 1 year after loading.

Materials and methods: In total, 104 consecutive patients received four 11 × 4.5 mm implants with a torque superior to 35 Ncm. If one implant did not reach a torque superior to 35 Ncm a fifth implant was added. If two implants did not reach a torque superior to 35 Ncm, loading was postponed after 3 months. A total of 127 metal-resin screw-retained fixed prostheses (59 mandibular and 68 maxillary) were to be delivered within 3 days. Outcome measures, evaluated by the treating clinician, were: prosthesis and implant failures, as well as complications.

Results: In total, 549 implants were placed (195 immediate post-extractive implants). Twelve maxillary prostheses were delayed loaded, whereas all others were loaded immediately. One year after loading, six patients dropped out, 12 implants failed in eight patients (two patients lost three implants each), and 87 prostheses were remade in 68 patients, one because of three implant failures and then again in the recall programme (replaced twice), one because of tree implant failures and five prosthesis fractures, 10 because of prostheses fractures and 74 in a recall programme for prosthesis replacement. All patients were wearing the planned fixed prostheses at the end of the first year in function. Ninety-eight complications occurred in 66 patients, but all were successfully solved.

Conclusions: Immediately loaded cross-arch prostheses supported by four to five implants are a viable therapeutic option, if prostheses are made with resistant frameworks.

This section presents a brief review of articles on dental implants considered of special interest for the reader, in order to encourage the development of research, the interest for data analysis and the attention to scientific publications. Your comments are welcome. Please contact Dr Michele Nieri at michelenieri@gmail.com.

Aims: This review assessed the available evidence on the performance of CAD/CAM monolithic implant-supported restorations bonded to titanium (Ti) inserts and bases, which has become a popular concept.

Materials and methods: An electronic and manual search of PubMed databases was conducted to identify studies published in English between 2000 and 2016 on the performance of monolithic ceramic implant restorations with Ti inserts.

Results: The initial search revealed 505 titles. Full-text screening was carried out for 70 studies, yielding 25 articles that met the inclusion criteria. No clinical studies could be identified regarding the performance of monolithic ceramic restorations bonded to Ti inserts. Laboratory studies on selected aspects and studies on similar prosthetic designs indicate that Ti inserts improve the overall fracture strength of ceramic abutments and crowns, protect the implant connection from wear, and offer a better marginal fit when compared with all-ceramic abutments.

Conclusions: While laboratory studies and evaluations of similar designs indicated promising outcomes, clinical studies that evaluate the performance of CAD/CAM monolithic implant-supported restorations bonded to Ti inserts and bases are needed.

Purpose: The aim of this study was to compare clinical and radiographic bone level assessments to intra-surgical bone level registration around implants with peri-implantitis and to identify the clinical variables rendering peri-implant bone level assessment accuracy.

Materials and methods: The study sample included 50 implants with peri-implantitis in 23 patients. Registration methods included probing of the vertical distance between the implant/abutment interface and the bottom of the pocket (= VPD), intraoral radiography, bone sounding without flap elevation and intra-surgically assessed interproximal bone level. The latter was considered the true bone level (gold standard). Twenty clinicians evaluated all radiographs.

Results: VPD and intraoral radiography resulted in a significant underestimation of the true bone level by 1.0 mm (95% CI: 0.495-1.585; P < 0.001) and 2.3 mm (95% CI: 1.650-2.980; P < 0.013) respectively. Bone sounding without flap elevation did not differ significantly from the true bone level (mean difference 0.2 mm; 95% CI: -0.775 - 0.335; P = 0.429). Duplicate magnification registration of 50 implants resulted in excellent intra- and inter-rater reliability (ICC intra ≤ 0.99; ICC inter = 0.964; P < 0.001). Radiographic underestimation was significantly affected by defect depth (P < 0.001). Variation among clinicians was substantial (mean underestimation range 1.1 mm to 3.8 mm); however, clinical experience had no impact on radiographic underestimation (P = 0.796).

Conclusions: Bone sounding without flap elevation was the best predictor of peri-implant bone level, whereas intraoral radiography was the most inferior. Consequently, peri-implantitis may be under-diagnosed if examination is only based on radiographs. Conflict-of-interest statement: Prof Hugo De Bruyn is associated with education and research collaboration agreements with Dentsply Sirona and Southern Implants, on behalf of Ghent University. Prof Cosyn has a collaboration agreement with Nobel Biocare. All other authors declare that they have no conflict of interest.

Purpose: To compare the outcome of dental implants placed following full-thickness flap surgery with flapless surgery in controlled type 2 diabetic patients.

Materials and methods: A total of 92 controlled type 2 diabetic patients, who needed missing mandibular first molars to be replaced by implants, were selected for a single-centre, parallel group, double-blinded randomised controlled trial. Patients were randomly allocated into two groups: flap (46 patients) vs flapless (46 patients) implant placement. Implants were loaded with metal-ceramic crowns, 4 months after placement in both groups.

Outcome measures: Implant and crown success, complications, post-operative pain and swelling, plaque index, sulcular bleeding index, pocket depth and HbA1c level. Follow up examinations were made after 24 h, and on the third and seventh days for soft tissue healing, pain and swelling evaluation; then at 6 months and 12 months (after loading) for dental plaque, sulcular bleeding, pocket depth, and HbA1c level evaluation.

Results: After 16 months of implant placement, no dropouts occurred. Five implants failed, two in the flap group and three in the flapless group (4.34% vs 6.52%, McNemar test P = 1, difference = 0.4457, 95% CI of difference = 4.554 to 47.234). Seven prosthesis failures occurred, three in the flap group and four in the flapless group (McNemar test P = 1; difference = 0.4239; 95% CI of difference = 29.95 to 3.86). Two patients in each group were affected by complications. There were statistically insignificant differences in the incidence of complications between the groups (McNemar test P = 1; difference = 0.457; 95% CI of difference = 90.75 to 5.33). After 24 h, the flapped group patients showed significantly greater pain compared with the flapless group (24 h: P = 0.017, difference = 0.37 and 95% CI = 0.673 to -0.067). After the third and seventh postoperative days, the mean pain level in both groups decreased linearly after the treatments (third day: P = 0.183, difference = 0.19 and 95% CI = -0.472 to 0.092; seventh day: P = 0.225, difference = 0.09 and 95% CI = -0.237 to 0.056). The frequency of post-operative swelling "some + a lot" at the third day was significantly higher in the full thickness flap group compared with the flapless group (P = 0.002, difference = 0.1835 and 95% CI = -0.0409 to 0.4079). Most of the cases in either of the study groups demonstrated no swelling (P =1.00, difference = 0.00 and 95% CI = -0.3034 to 0.3034) on the seventh post-operative day. The mean plaque index (6 months: 1.00 ± 0.47 vs 0.83 ± 0.79, P = 0.230, difference = 0.17 and 95% CI = -0.450 to 0.110 and 12 months: 1.30 ± 0.67 vs 1.04 ± 0.86, P = 0.123, difference = 0.26 and 95% CI = 0.593 to 0.073), mean sulcular bleeding index (6 months: 1.40 ± 0.52 vs 1.04 ± 0.83, P = 0.018, difference = 0.36 and 95% CI = 0.658 to 0.062 and 12 months: 1.90 ± 0.48 vs 1.17 ± 0.57, P

Purpose: To compare prosthesis and implant failure, patient satisfaction, prosthetic complications and peri-implant marginal bone loss of mandibular overdentures (IOD) supported by a single or two implants.

Materials and methods: Manual and electronic database (PubMed and Cochrane) searches were performed to identify randomised controlled trials, without language restriction, comparing single vs two implant supported mandibular overdentures. Two investigators extracted data independently. The Cochrane tool was used for assessing the quality of included studies. Meta-analyses were performed for the included RCTs.

Results: Six publications corresponding to four RCTs were identified. Three RCTs (corresponding to five publications) were included and one trial was excluded. Follow-ups in function were 1, 3 and 5 years after loading. All included studies were considered to be at a high risk of bias. The pooled result revealed more prosthesis failures at overdentures supported by two implants at 1 year (three trials) (P = 0.02; Risk Difference: -0.12, 95% CI: -0.22, -0.02), however, there were non-significant differences at 3 years (two trials) (P = 0.22; Risk Difference: -0.32, 95% CI: -0.83, 0.19) and at 5 years (one trial) (P = 0.95; Risk Difference: 0.01, 95% CI: -0.22, 0.24). Regarding implant failures, there were more implant losses in overdentures supported by two implants at 1 year (three trials) (P = 0.02; Risk Difference: -0.12, 95% CI: -0.22, -0.02) and at 5 years (one trial) (P = 0.95; Risk Difference: -0.15, 95% CI: -0.28, -0.02), however, there were non-significant difference at 3 years (two trials) (P = 0.2; Risk Difference: -0.33, 95% CI: -0.84, 0.18). After 5 years in function, meta-analyses revealed that there were non-significant differences regarding overall prosthetic complications when mandibular overdentures supported by a single implant were compared with overdentures supported by two implants (P = 0.43; RD: 0.04, 95% CI: -0.06, 0.15).

Conclusion: Mandibular overdentures retained by a single implant have comparable results to those retained by two implants. However, this should be interpreted with caution as all the included studies were considered at a high risk of bias.