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

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

Which substances loaded onto collagen scaffolds influence oral tissue regeneration?-an overview of the last 15 years.

BACKGROUND: Collagen scaffolds are widely used for guided bone or tissue regeneration. Aiming to enhance their regenerative properties, studies have loaded various substances onto these scaffolds. This review aims to provide an overview of existing literature which conducted in vitro, in vivo, and clinical testing of drug-loaded collagen scaffolds and analyze their outcome of promoting oral regeneration. MATERIALS AND METHODS: PubMed, Scopus, and Ovid Medline® were systematically searched for publications from 2005 to 2019. Journal articles assessing the effect of substances on oral hard or soft tissue regeneration, while using collagen carriers, were screened and qualitatively analyzed. Studies were grouped according to their used substance type-biological medical products, pharmaceuticals, and tissue-, cell-, and matrix-derived products. RESULTS: A total of 77 publications, applying 36 different substances, were included. Collagen scaffolds were demonstrating favorable adsorption behavior and release kinetics which could even be modified. BMP-2 was investigated most frequently, showing positive effects on oral tissue regeneration. BMP-9 showed comparable results at lower concentrations. Also, FGF2 enhanced bone and periodontal healing. Antibiotics improved the scaffold's anti-microbial activity and reduced the penetrability for bacteria. CONCLUSION: Growth factors showed promising results for oral tissue regeneration, while other substances were investigated less frequently. Found effects of investigated substances as well as adsorption and release properties of collagen scaffolds should be considered for further investigation. CLINICAL RELEVANCE: Collagen scaffolds are reliable carriers for any of the applied substances. BMP-2, BMP-9, and FGF2 showed enhanced bone and periodontal healing. Antibiotics improved anti-microbial properties of the scaffolds.

A multicenter randomized controlled trial using a novel collagen membrane for guided bone regeneration at dehisced single implant sites: Outcome at prosthetic delivery and at 1-year follow-up.

OBJECTIVES: To compare clinical performance of a novel resorbable non-cross-linked collagen membrane (CXP) with a reference membrane (non-cross-linked resorbable membrane; BG) for simultaneous implant placement and guided bone regeneration (GBR) at dehisced single implant sites. MATERIALS AND METHODS: Preliminary data from this randomized controlled trial were reported previously; this is the 12-month report. The primary outcome measure was defected height at 6 months post-GBR. Secondary outcomes included implant cumulative survival rate (CSR) and success rate since placement; bone level changes, pink esthetic score (PES), and patient satisfaction since definitive prosthesis delivery; patient quality of life since pretreatment; and the 1-year bleeding index. Non-parametric statistical analyses were performed. RESULTS: Among patients, 24 were treated with CXP and 25 with BG. The 1-year implant CSR and success rate were 100% (n = 42). Bone level change between definitive prosthetic delivery and 1 year was not significantly different between the CXP and BG groups (BG + 0.42 mm, CXP + 0.01 mm). The PES increased from 7.55 to 8.10 for the CXP group and from 6.48 to 7.48 for the BG group; 1-year bleeding indices were 0 (16 CXP, 18 BG) and 1 (4 CXP, 2 BG). Patient quality of life changed from an OHIP-14 score of 6.5 at pretreatment to 1.9 at 1 year. Overall satisfaction (visual analogue score) with function and esthetics was 9.9 and 9.7, respectively. Inter-group differences were not significant for assessed outcomes. No device-related adverse events were reported. CONCLUSIONS: The use of CXP and BG for simultaneous implant placement and GBR at dehisced implant sites similarly reduced defect height and improved secondary measures, indicating non-inferiority.

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

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

The Influence of Type 2 Diabetes Mellitus on the Osseointegration of Titanium Implants With Different Surface Modifications-A Histomorphometric Study in High-Fat Diet/Low-Dose Streptozotocin-Treated Rats.

OBJECTIVES: Type 2 diabetes mellitus (T2DM) is a systemic disease that also compromises the bone healing capacity. In healthy individuals, surface modifications of dental implants are proven to increase bone response and implant success. The aim of this study was to clarify if the surface modifications also improve osseointegration in a setting with diabetes mellitus. METHODS: T2DM was induced in 7 rats by a high-fat diet/low-dose streptozotocin injection. All animals received a hydroxyapatite (HA) implant, a sandblasted and acid-etched (SLA) implant, and a standard machined titanium implant for control in the tibia. After 4 weeks, thin-ground sections were produced, and the volume of new bone formation (nBV/TV) and bone-to-implant contact (nB.I/Im.I) were histomorphometrically analyzed. RESULTS: Both surface modifications led to an increase of osseointegration compared with the machined surface implant in rats with T2DM. nBV/TV was highest in the SLA implants, whereas nB.I/Im.I was highest in the HA group. Regardless of the surface modification, a superordinate regional pattern of new bone formation over the length of the implant was observed. CONCLUSIONS: Implants with HA coating and SLA surface modifications seem to have the potential to increase osseointegration also in T2DM rats when compared with a conventional machined surface.

Evaluation of implant esthetics using eight objective indices-Comparative analysis of reliability and validity.

OBJECTIVES: The aim of the present study was to give a detailed analysis on eight proposed implant esthetic indices including a total of 48 parameters with respect to validity and reproducibility as well as its correlation to patients' perception of esthetics. MATERIAL AND METHODS: Standardized intraoral photographs of 189 patients with 189 implant-supported crowns and adjacent peri-implant soft tissue in the esthetic zone (central and lateral incisors, canine, first premolar) served as basis for this evaluation. Eight indices (Papilla Index [PI], Pink Esthetic Score [PES], Implant Crown Aesthetic Index [ICAI], Pink and White Esthetic Score [PES/WES], Complex Esthetic Index [CEI], Implant Aesthetic Score [IAS], Subjective Esthetic Score [SES], and Rompen Index) with a total of 48 parameters were selected. Esthetic evaluation was performed twice by five examiners with an interval of 4 weeks between the evaluations. RESULTS: A total of 1,890 evaluations including eight esthetic indices served as basis for the statistical analysis. Among the overall main scores tested for inter-rater reliability, the highest ρ^inter values were computed for CEI, PES, PI, and IAS scores. By contrast, SES and Rompen showed the worst inter-rater reliability, respectively. The highest level of intra-rater reproducibility was noted for PI, PES, and CEI. The lowest level of intra-rater reproducibility showed Rompen, SES, and ICA. The Papilla Index demonstrated the highest level of inter-rater reliability. The remainder of the single variables (n = 46) did not reach the ρ^inter level of 0.6. The single variables PI mesial, PI distal as well as CEI P4 showed the highest ρ^intra with statistical significance higher than 0.8. The lowest agreement was observed among the variables ICA3, WES5, and IASm2. In general, VAS did not show any good correlation to the esthetic indices proposed so far. The influence of esthetic parameters on subjective patient satisfaction was generally low. CONCLUSION: In conclusion, significant differences regarding reliability and validity could be observed in the present comparison of eight esthetic indices. Objective evaluation of the esthetic outcome of implant therapy inherently fails to reflect subjective patient opinion, however, requires consistency of results to enable between-study comparison and meta-analysis.

Immediate provisionalization in the esthetic zone: 1-year interim results from a prospective single-cohort multicenter study evaluating 3.0-mm-diameter tapered implants.

OBJECTIVES: The aim of this interim analysis of a 5-year prospective multicenter study is to evaluate clinical and radiological performance of immediately provisionalized 3.0-mm-diameter tapered implants. MATERIALS AND METHODS: Patients needing implant rehabilitation of maxillary lateral incisors or mandibular lateral and central incisors were treated with 3.0-mm-diameter implants placed in extraction or healed sites and immediately provisionalized. Clinical and radiographic examinations were performed at implant insertion, 6 months thereafter, and are ongoing. Marginal bone levels and changes, complications, the papilla, plaque, and bleeding indices, and the pink esthetic score (PES) were evaluated at each follow-up visit. RESULTS: Of 112 enrolled patients, 77 patients (91 implants) met the inclusion criteria. Seventy-one patients with 82 implants completed the 1-year follow-up. Three implants failed yielding a CSR of 96.7%. All failures occurred within the first 3 months after implant insertion. Marginal bone level changes from insertion to 6 months was - 0.57 ± 1.30 mm (n = 75) and from insertion to 12 months - 0.25 ± 1.38 mm (n = 72). Fifteen non-serious complications were recorded. Papilla index score and PES improved at the 1-year follow-up. Plaque formation and bleeding-on-probing showed no statistically significant differences between the 6-month and the 1-year visit. CONCLUSIONS: This 1-year analysis demonstrated high survival, stable bone levels, and healthy soft tissue with 3.0-mm-diameter implants. CLINICAL IMPLICATIONS: Narrow diameter implants are a safe and predictable treatment option in patients with limited bone volume and/or limited interdental space and eligible for immediate loading protocols.

A multicenter randomized controlled clinical trial using a new resorbable non-cross-linked collagen membrane for guided bone regeneration at dehisced single implant sites: interim results of a bone augmentation procedure.

OBJECTIVE: To compare clinical performance of a new resorbable non-cross-linked collagen membrane, creos xenoprotect (CXP), with a reference membrane (BG) for guided bone regeneration at dehisced implant sites. MATERIALS AND METHODS: This randomized controlled clinical trial enrolled patients with expected dehiscence defects following implant placement to restore single teeth in the maxillary and mandibular esthetic zone and premolar area. Implants were placed using a two-stage surgical protocol with delayed loading. Bone augmentation material placed at the implant surface was immobilized with CXP or BG membrane. Soft tissue health was followed during the healing period, and the defect size was measured at reentry and 6 months after implant placement. RESULTS: Of the 49 included patients, 24 were treated with CXP and 25 with BG. Patient characteristics did not differ between the two arms. In the CXP arm, the defect height at implant insertion was (mean ± SD) 5.1 ± 2.1 mm (n = 24) and reduced at reentry by 81% to 1.0 ± 1.3 mm (n = 23). In the BG arm, the defect height at implant insertion was 4.9 ± 1.9 mm (n = 25) and reduced at reentry by 62% to 1.7 ± 2.1 mm (n = 24). Assuming a margin of non-inferiority of 1 mm, CXP was non-inferior to BG. Membrane exposure rate was highest at week 3 in both arms, reaching 16.7% for BG and 8.7% for CXP. CONCLUSIONS: The new resorbable non-cross-linked collagen membrane facilitates bone gain to support implant placement in expected dehiscence defects. The observed trend toward higher mean bone gain and lower exposure rate with CXP compared to BG should be further investigated.

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

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

Multiple Perforations of the Sinus Floor During Maxillary Sinus Floor Augmentation to Provide Access to the Bone Marrow Space: A Technical Report.

INTRODUCTION: Sinus floor augmentation is a routinely used surgical technique for increasing the bone height/volume of the atrophic posterior maxilla. Optimal integration of the implanted augmentation material within the newly formed bone will-at least partly-depend on adequate vascularization to ensure sufficient recruitment of osteoblast and osteoclast precursor cells. METHODS: The present technical note describes a modification intended to facilitate increased blood inflow into the augmented space. After preparation of the lateral window and elevation of the Schneiderian membrane, the cortical bone of the sinus floor is perforated several times either by using a piezoelectric device or a microsurgical handpiece with the corresponding tip or bur; these perforations should extend into the trabecular bone. RESULTS AND CONCLUSION: The experiences with this modified technique after 12 patients are presented and discussed. It is expected that by means of this relatively simple technique, increased blood and cell inflow into the augmented space is achieved. This may, in turn, enhance new bone formation and improve the integration of the augmentation material.

Dental implants are a viable alternative for compensating oligodontia in adolescents.

OBJECTIVES: To clinically and radiographically evaluate dental implant treatment in adolescents with extensive oligodontia. METHODS: Patients with more than nine permanent teeth congenitally missing and implant treatment before the age of 16 years were included. Clinical follow-ups involved bleeding on probing, plaque index and peri-implant probing value. The peri-implant bone level was analysed on panoramic radiographs at time of implant treatment and at follow-up. Characteristics of the dental implants and patients were retrieved. RESULTS: This study involved 18 patients (nine males, nine females) having 71 dental implants. The lower left premolar was predominantly missing. The mean age at the time of dental implant treatment was 12.5 (± 2.6) years. The bleeding on probing value was determined negative on 44%. The mean pocket depth was 3.6 (± 1.1) mm. The peri-implant bone level correlated significantly negative with the age at time of implant placement (r = -0.346, P = 0.004). The region of implant habits had no influence on peri-implant bone level. Dental implant treatment in adolescents resulted in a survival rate of 89% (63/71) and a mean loading time of 11.0 (± 4.1) years. The implant crowns to be renewed resulted in 54% (9 of 18 patients, 38 of 71 crowns) after a period of 7.8 ± 4.5 years. CONCLUSION: Dental implant treatment in maturing adolescents with extensive oligodontia before is supported by the data of the present study. Providing that other treatment options are considered, the areas of skeletal growth are respected and the patients are well informed. To enhance quality of life of growing children with oligodontia clinicians are asked to evaluate their long-term outcome on dental implant treatment in adolescents.

Clinical and radiological evaluation of a template-guided (NobelGuide™) treatment concept.

OBJECTIVES: The study was designed to evaluate the clinical use of the NobelGuide(™) concept over a follow-up period of 12 months with respect to implant success and survival rates, development of soft tissue condition and recording of potential surgical and prosthetic complications. In addition, radiological assessment of peri-implant bone levels was performed at the 1-year follow-up post-implant placement. MATERIAL AND METHODS: Thirty patients (male/female = 15/15) with partially dentate and edentulous mandibles and maxillae were included. All patients were planned and operated on using the computer-aided, template-guided treatment concept NobelGuide(™). Overall, 163 implants (NobelReplace(®) Tapered Groovy) were placed (mandible/maxilla = 107/56 implants). Recall appointments were performed after 1-2 weeks, 1, 3, 6 and 12 months after implant placement. Clinical parameters of the soft tissue conditions [e.g. bleeding on probing (BoP), pocket probing depth ≥3 mm (PPD), marginal plaque index (mPI)] and the dentist's esthetic and functional evaluation using a visual analogue scale (VAS) were documented. Marginal bone level was evaluated on radiographs made at implant insertion and at the 1-year follow-up. RESULTS: All 30 patients with 161 implants completed the 1-year follow-up resulting in a cumulative survival rate of 98.8% (two implant losses). Clinical parameters improved in a majority of the implants. The mean marginal bone level at implant insertion and at 1-year follow-up was reported with 0.17 mm (SD 1.24; n = 125) and -1.39 mm (SD 1.27; n = 110), respectively. The mean change in bone level from implant insertion to 1 year was -1.44 mm (SD 1.35; n = 98). CONCLUSIONS: The 1-year follow-up showed a cumulative survival rate and success rate of 98.8% and 96.3%, respectively. Immediate or delayed loading of implants using a flapless, guided surgery approach (NobelGuide(™)) appears to be a viable concept demonstrating good clinical and radiographic outcomes at the 1-year time point.

A novel standardized bone model for thermal evaluation of bone osteotomies with various irrigation methods.

OBJECTIVES: Based on a novel standardized bovine specimen, the aim of this study was to investigate thermal effects of different irrigation methods during intermittent and graduated drilling. MATERIAL AND METHODS: Temperature changes during implant osteotomies (n = 320) of 10 and 16 mm drilling depths with various irrigation methods were investigated on manufactured uniform bone samples providing homogenous cortical and cancellous areas and analogous thermal conductivity comparable to human bone. Automated sequences were performed with surgical twist drills of 2 mm ∅ and conical drills of 3.5, 4.3 and 5 mm ∅. Real-time recording of temperature increase was done using two custom-built multichannel thermoprobes with 14 temperature sensors at a predefined distance of 1 and 2 mm to the final osteotomy. The effects of drilling depth, drilling diameter and irrigation methods on temperature changes were investigated by a linear mixed model. RESULTS: Using this uniform bone specimen, the greatest temperature rise was observed without any coolant supply with 29.87°C, followed by external with 28.47°C and then internal with 25.86°C and combined irrigation with 25.68°C. Significant differences (P ≤ 0.0156) between drill depths of 10 vs. 16 mm could be observed with all irrigation methods evaluated. With each of the irrigation methods, significantly higher temperature changes (P < 0.0001) during osteotomies could be observed between twist drills of 2 mm ∅ and conical drills of 3.5, 4.3 and 5 mm ∅. During 10 and 16 mm drilling osteotomies, external irrigation showed significantly higher temperatures (P < 0.05) for all conical drills compared with internal or combined irrigation, respectively. Significantly lower temperatures (P < 0.05) could be detected with internal or combined irrigation for the use of conical drills with various diameters and drilling depths. CONCLUSIONS: This fully standardized bone model provides optimized comparability for the evaluation of bone osteotomies and resulting temperature changes. As regards the efficiency of the various irrigation methods, it could be demonstrated that internal and combined irrigation appears to be more beneficial than external irrigation.

Thermal effects of a combined irrigation method during implant site drilling. A standardized in vitro study using a bovine rib model.

OBJECTIVES: The purpose of this study was to evaluate the temperature changes during implant osteotomies with a combined irrigation system as compared to the commonly used external and internal irrigation under standardized conditions. MATERIAL AND METHODS: Drilling procedures were performed on VII bovine ribs using a computer-aided surgical system that ensured automated intermittent drilling cycles to simulate clinical conditions. A total of 320 drilling osteotomies were performed with twist (2 mm) and conical implant drills (3.5/4.3/5 mm) at various drilling depths (10/16 mm) and with different saline irrigation (50 ml/min) methods (without/external/internal/combined). Temperature changes were recorded in real time by two custom-built thermoprobes with 14 temperature sensors (7 sensors/thermoprobe) at defined measuring depths. RESULTS: The highest temperature increase during osteotomies was observed without any coolant irrigation (median, 8.01°C), followed by commonly used external saline irrigation (median, 2.60°C), combined irrigation (median, 1.51°C) and ultimately with internal saline irrigation (median, 1.48°C). Temperature increase with different drill diameters showed significant differences (P < 0.05) regarding drill depth, confirming drill depth and time of drilling as influencing factors of heat generation. Internal saline irrigation showed a significantly smaller temperature increase (P < 0.05) compared with combined and external irrigation. A combined irrigation procedure appears to be preferable (P < 0.05) to an external irrigation method primarily with higher osteotomy depths. CONCLUSIONS: Combined irrigation provides sufficient reduction in temperature changes during drilling, and it may be more beneficial in deeper site osteotomies. Further studies to optimize the effects of a combined irrigation are needed.

Clinical and Radiographic Outcomes of Single Implant-Supported Zirconia Crowns Following a Digital and Conventional Workflow: Four-Year Follow-Up of a Randomized Controlled Clinical Trial.

PURPOSE: This study aimed to compare the clinical and radiographic outcomes of single posterior screw-retained monolithic implant crowns following a digital and conventional workflow and to report on the survival/complication rate after a mean 4-year follow-up. MATERIALS AND METHODS: Thirty patients with a single posterior tooth missing were rehabilitated with a bone-level implant. After a healing period of ≥3 months, they were subjected to both a digital and conventional workflow to fabricate two screw-retained monolithic implant crowns. The quantitative clinical adjustments to both crowns (intrasubject comparison) and a questionnaire were recorded at try-in. Thereafter, a crown of the digital and conventional workflows was randomly inserted. At the last follow-up, the marginal bone level (MBL), peri-implant health-related parameters (bleeding on probing (BoP), plaque, pocket probing depth (PPD)), and functional implant prosthodontic score (FIPS) were assessed. Furthermore, the implant survival and success rates and technical complications were evaluated. RESULTS: A total of 27 patients were followed for a mean period of 4.23 ± 1.10 years. There was no significant difference between the digital and conventional workflows regarding clinical adjustments and questionnaire outcomes. More than twice as many participants recommended digital (n = 16) compared to conventional impressions (n = 7) to friends. The implant survival and success rate were 100% and 96.3%, respectively. Furthermore, two de-cementations and one fracture of the ti-base abutment occurred. There were no significant differences in BoP, plaque, and PPD metrics between the two groups. The changes in the MBL between implant crown insertion (baseline) and the last follow-up were 0.07 ± 0.19 mm and 0.34 ± 0.62 mm in the digital and conventional groups, respectively (p = 0.195). The mean overall FIPS score was 8.11 ± 1.37 (range: 5-10). CONCLUSIONS: The clinical and radiographic outcomes of single screw-retained monolithic implant crowns were similar between both workflows after a mean of 4 years of service. The patients did not clearly prefer an impression technique for their restoration, although they would recommend the digital impression more often to friends. Thus, decision regarding clinical workflows may be based on the patient's and/or clinician's preference.

Impact of implant surface topography: a clinical study with a mean functional loading time of 85 months.

OBJECTIVE: Moderately rough, surfaced implants are widely used. Nevertheless data on long-term soft and hard tissue parameters are still conflicting. The purpose of this study was to evaluate peri-implant bone level and soft tissue integration of anodized vs. turned surfaced implants in the anterior mandible after a mean functional loading time of 85 months. METHODS: Of 114 edentulous patients invited for follow-up, 41,2% were available for recall. Forty-seven patients with a mean age of 71 ± 9 years (14 men and 33 women) received 188 dental implants; All patients were edentulous and prosthetic rehabilitation was carried out by a bar-retained overdenture. Radiographic peri-implant bone level was assessed twice at baseline and recall. Clinical examination contained peri-implant sounding (PPD, BoP) and indexing oral hygiene (mPI). RESULTS: From baseline up to 85 months two patients experienced implant loss (four implants), which corresponds to an overall-survival rate of 97.9%. No significant differences were found between implant surfaces concerning the clinical parameters, such as plaque, calculus, bleeding on probing and pocket probing depth. The moderately rough surfaced implants showed significantly less decrease in peri-implant bone level (1.53 ± 0.25 mm) than turned surfaced implants (2.42 ± 0.34 mm) (P = 0.036). The interaction between the position of the implant and surface topography (P = 0.037) as well as the site at the implant (P = 0.004) had a significant influence on bone level changes. CONCLUSION: Both surface topographies with bar-supported overdentures have excellent long-term clinical outcomes. Moreover, a moderately roughened, anodized surface has beneficial effects in the anterior lower jaw.

Prevalence, location and morphology of maxillary sinus septa: systematic review and meta-analysis.

AIM: To gain further insights and resolve conflicting results in the literature regarding prevalence, predominant location and morphologic variability of maxillary sinus septa. MATERIAL AND METHODS: Electronic and hand searching of English literature identified 33 investigations published from 1995 to 2011. Septa were defined as at least 2-4 mm in height. RESULTS: Septa were present in 28.4% of 8923 sinuses investigated (95% confidence interval: 24.3-32.5%). Prevalence was significantly higher in atrophic sinuses compared with dentate maxillae (p < 0.001). Septa were located in premolar, molar and retromolar regions in 24.4%, 54.6% and 21.0% respectively. Orientation of septa was transverse in 87.6%, sagittal in 11.1% and horizontal in 1.3% of cases. Septa height measured 7.5 mm on average. Complete septa (dividing the sinus into two separate cavities) were found in only 0.3%. Other rare conditions included multiple septa in one sinus (4.2%) and bilateral septa (17.2%). Septa diagnosis using panoramic radiographs yielded incorrect results in 29% of cases. CONCLUSIONS: In view of their high overall prevalence and significant morphologic variability, 3D radiographic imaging prior to sinus floor augmentation may help to reduce complication rates in the presence of maxillary sinus septa.

Biomechanical finite element analysis of short-implant-supported, 3-unit, fixed CAD/CAM prostheses in the posterior mandible.

OBJECTIVE: To assess the biomechanical effects of different prosthetic/implant configurations and load directions on 3-unit fixed prostheses supported by short dental implants in the posterior mandible using validated 3-D finite element (FE) models. METHODS: Models represented an atrophic mandible, missing the 2nd premolar, 1st and 2nd molars, and rehabilitated with either two short implants (implant length-IL = 8 mm and 4 mm) supporting a 3-unit dental bridge or three short implants (IL = 8 mm, 6 mm and 4 mm) supporting zirconia prosthesis in splinted or single crowns design. Load simulations were performed in ABAQUS (Dassault Systèmes, France) under axial and oblique (30°) force of 100 N to assess the global stiffness and forces within the implant prosthesis. Local stresses within implant/prosthesis system and strain energy density (SED) within surrounding bone were determined and compared between configurations. RESULTS: The global stiffness was around 1.5 times higher in splinted configurations vs. single crowns, whereby off-axis loading lead to a decrease of 39%. Splinted prostheses exhibited a better stress distribution than single crowns. Local stresses were larger and distributed over a larger area under oblique loads compared to axial load direction. The forces on each implant in the 2-implant-splinted configurations increased by 25% compared to splinted crowns on 3 implants. Loading of un-splinted configurations resulted in increased local SED magnitude. CONCLUSION: Splinting of adjacent short implants in posterior mandible by the prosthetic restoration has a profound effect on the magnitude and distribution of the local stress peaks in peri-implant regions. Replacing each missing tooth with an implant is recommended, whenever bone supply and costs permit.

Experimental validation of a micro-CT finite element model of a human cadaveric mandible rehabilitated with short-implant-supported partial dentures.

PURPOSE: This study aimed to address the predictive value of a micro-computed tomography (µCT)-based finite element (µFE) model of a human cadaveric edentulous posterior mandible, rehabilitated by short dental implants. Hereby, three different prosthetic/implant configurations of fixed partial dentures ("Sp"-3 splinted crowns on 3 implants, "Br" - Bridge: 3 splinted crowns on 2 implants, and "Si"- 3 single crowns) were analysed by comparing the computational predictions of the global stiffness with experimental data. METHODS: Experimental displacement of the bone/implant/prosthesis system was measured under axial and oblique loads of 100 N using an optical deformation system (GOM Aramis) and the overall movement of the testing machine (Zwick Z030). Together with the measured machine force, an "Aramis" (optical markers) and "Zwick" (test machine) stiffness were calculated. FE models were created based on µCT-scans of the cadaveric mandible sample (n = 1) before and after implantation and using stl-files of the crowns. The same load tests and boundary conditions were simulated on the models and the µFE-results were compared to experimental data using linear regression analysis. RESULTS: The regression line through a plot of pooled stiffness values (N/mm) for the optical displacement recording (true local displacement) and the test machine (machine compliance included) had a slope of 0.57 and a correlation coefficient R2 of 0.82. The average pooled correlation of global stiffness between the experiment and FE-analysis (FEA) showed a R2 of 0.80, but the FEA-stiffness was 7.2 times higher. The factor was highly dependent on the test configuration. Sp-configuration showed the largest stiffness followed by Br-configuration (17% difference in experiment and 21% in FEA). CONCLUSIONS: The current study showed good qualitative agreement between the experimental and predicted global stiffness of different short implant configurations. It could be deduced that 1:1 splinting of the short implants by the crowns is most favorable for the stiffness of the implant/prosthesis system. However, in the clinical context, the absolute in silico readings must be interpreted cautiously, as the FEA showed a considerable overestimation of the values.

Progress and trends in patients' mindset on dental implants. II: implant acceptance, patient-perceived costs and patient satisfaction.

OBJECTIVES: compared with widespread investigations on dental implant survival and biologic parameters, patient-based outcomes of implant dentistry have been neglected for years and are now becoming more popular. The aim of this representative opinion poll was to assess the up-to-date patients' mindset on dental implants and draw comparisons with the results published in 2003. MATERIAL AND METHODS: one thousand adults - representative for the Austrian population - were presented with a total of 16 questionnaire items regarding acceptance and subjectively perceived costs of dental implant treatment as well as patient satisfaction with implant-supported rehabilitation. RESULTS: the implant acceptance rate was 56%, while 23% of the interviewees decidedly rejected implant treatment (same rate as in 2003), especially those over 50 years of age. Only 5% had themselves undergone implant treatment and 22% reported to know someone fitted with implants. The estimated costs of implant treatment were significantly higher than those in 2003, and three-quarters felt that the prize was too high and that the sick fund or social security agencies should bear them. Satisfaction scores were significantly higher among interviewees wearing implant-supported rehabilitations compared with those with conventional fixed or removable dentures. CONCLUSIONS: little has changed in patients' attitude toward dental implants compared with the representative opinion poll in 2003. Neither implant acceptance nor implant prevalence in the Austrian population demonstrated upward trends. Professional public relations efforts are indicated to drop resentments and increase patient acceptance of dental implants as a treatment modality.