Evaluation of a Variable‐Thread Tapered Implant in Extraction Sites With Immediate Temporization: A 3‐Year Multicenter Clinical Study

Background: The purpose of this clinical study is to evaluate the radiographic bone remodeling, survival rate, and soft tissue health surrounding a variable‐thread tapered implant immediately placed in extraction sites. Methods: Sixty implants were placed in 55 patients at six centers according to a predetermined protocol. All implants were placed in extraction sockets and were subjected to immediate temporization and function. Definitive prostheses (58 single crowns and one two‐unit fixed bridge) were placed within the first year. Clinical and radiographic examinations were performed at implant placement and after 3, 6, 12, 24, and 36 months. Measurements of implant stability, papilla index, plaque, peri‐implant mucosa, and marginal bone levels were recorded at each visit. Results: Thirty‐five implants were evaluated at both implant insertion and 3‐year follow‐up. Bone levels were observed at 6 months after surgery and yearly intervals thereafter and remained stable throughout the study. There was a slight decrease in mean bone level from ?0.68 mm at implant insertion to ?0.93 mm at the 6‐month recall and then an increase of bone to ?0.53 mm from the reference point at the 2‐year follow‐up (an average increase of 0.15 mm from implant insertion). Bone levels remained steady between the 2‐year recall and the 3‐year recall. Papilla scores increased significantly (P <0.001; Wilcoxon signed‐rank test) from insertion to the 3‐year follow‐up, with most of the increase occurring during the first year. Patient assessments of function, esthetics, feel of implant, speech, and self‐esteem also showed significant improvement over the course of the study. Conclusions: The results, over 36 months, indicate that the variable‐thread tapered implant can be used safely and effectively under demanding conditions as an immediate postextraction tooth replacement. Bone remodeling remained stable with a slight increase, and patients expressed high levels of satisfaction with the restorative results over the course of the study.     

Long‐Term Function of Single‐Implant Restorations: A 17‐ to 19‐Year Follow‐Up Study on Implant Infraposition Related to the Shape of the Face and Patients' Satisfaction

Background: Various levels of infraposition of single‐implant restorations have been observed in long‐term follow‐up studies, but little knowledge is available on the biological mechanism behind this pattern. Purpose: The primary aim of this study is to report the frequency and severeness of implant infraposition in the anterior single‐implant application after 17 to 19 years in function and, secondly, to try to relate these observations to anatomical appearance of the shape of the face of the patient. Materials and Methods: The present study comprised of 57 patients who were provided with 65 CeraOne? single‐tooth restorations (Nobel Biocare AB, Gothenburg, Sweden) between 1989 and 1991. Altogether 46 of these patients were treated with single implants in the anterior region. Besides clinical and radiographic data, clinical photographs, study casts, and patient's assessment of the long‐term aesthetic result (visual analog scale) was collected at the termination of the present study. The degree of implant crown infraposition was related to assessed facial shape and to patient and clinical assessment of the aesthetic result by means of Pearson's correlation test. To increase the numbers of patients, another group of 25 patients presented in another similar study were pooled with the present material for prevalence calculations. Results: Altogether 47 patients showed up for the final examination after an average of 18 years (82%). Two implants failed (18 years cumulative survival rates [CSR]– 96.8%) and eight original single‐crown restorations were replaced (CSR 83.8%). Three of the replaced crowns were replaced because of infraposition of the crowns. About 40% of the patients showed signs of infraposition, similar in younger and older age groups, but more frequently observed in female patients at termination of the study (p < 0.05). There was a weak trend indicating an association between “long‐face” appearance and infraposition of the crown restoration (p > 0.05), and patients were more satisfied with the aesthetic clinical result than the participating clinicians (p < 0.05). Conclusion: Single‐implant restorations in the anterior upper jaw may present small degrees of infraposition in long‐term perspectives. Female patients seem to be at a higher risk of infraposition (p < 0.05), but no clear relationship between age at implant placement or facial shape and degree of infraposition was possible to establish (p > 0.05). Patients were more satisfied with the aesthetic result, as compared with the clinicians (p < 0.05), and patients seemed to pay less attention to the degree of infraposition in their aesthetic assessments, as compared with most of the clinicians.     

Food Impaction and Periodontal/Peri‐Implant Tissue Conditions in Relation to the Embrasure Dimensions Between Implant‐Supported Fixed Dental Prostheses and Adjacent Teeth: A Cross‐Sectional Study

Background: Food impaction and periodontal/peri‐implant tissue conditions were evaluated in relation to the embrasure dimensions between implant‐supported fixed dental prostheses (FDPs) and adjacent teeth. Methods: A total of 215 embrasures of 150 FDPs in 100 patients (55 males and 45 females, aged 27 to 83 years; mean age: 56 years) were included in the study. Clinical assessments of the periodontal/peri‐implant mucosal conditions, radiographic assessments of embrasure dimensions, and overall patient satisfaction were used as explanatory variables for the food impaction and periodontal/peri‐implant tissue conditions adjacent to implant‐supported FDPs in the generalized estimating equation (GEE) analysis. Results: Food impaction was reported in 96 (44.7%) of 215 embrasures between implant‐supported FDPs and adjacent teeth. Food impaction was reported more frequently in the embrasures with proximal contact loss than in those with tight contact (P = 0.009). Overall patient satisfaction was influenced negatively by food impaction in the proximal embrasures (P = 0.01). Among embrasure dimensions, only the embrasure surface area (ESA) significantly influenced food impaction (P = 0.03). Significant influences of various embrasure dimensions on the periodontal/peri‐implant mucosal conditions and bone level at the implant were found in the univariate and multivariate GEE analyses. Conclusions: Food impaction between implant‐supported FDPs and adjacent teeth occurred more frequently when proximal contact was lost and ESA increased. Food impaction negatively affected overall patient satisfaction. Embrasure dimensions influenced the periodontal/peri‐implant mucosal conditions and bone level at the implant.     

Stability of Contour Augmentation and Esthetic Outcomes of Implant‐Supported Single Crowns in the Esthetic Zone: 3‐Year Results of a Prospective Study With Early Implant Placement Postextraction

Background: Early implant placement is one of the treatment options after tooth extraction. Implant surgery is performed after a healing period of 4 to 8 weeks and combined with a simultaneous contour augmentation using the guided bone regeneration technique to rebuild stable esthetic facial hard‐ and soft‐tissue contours. Methods: In this prospective study, 20 patients were treated with an implant‐born single crown and followed for 3 years. Clinical, radiologic, and esthetic parameters were recorded to assess treatment outcomes. Results: At the 3‐year examination, all 20 implants were successfully integrated, demonstrating ankylotic stability and healthy peri‐implant soft tissues as documented by standard clinical parameters. Esthetic outcomes were assessed by the pink esthetic score (PES) and white esthetic score (WES) and confirmed pleasing results overall. WES values were slightly superior to PES values. Periapical radiographs showed minimal crestal bone loss around used bone‐level implants with a mean bone loss of 0.18 mm at 3 years. Only two implants revealed bone loss between 0.5 and 1.0 mm. One of these implants had minor mucosal recession <1.0 mm. Conclusions: This prospective study evaluates the concept of early implant placement and demonstrated successful tissue integration for all 20 implants and stable bone‐crest levels around implant–abutment interfaces according to the platform‐switching concept. The midterm 3‐year follow‐up revealed pleasing esthetic outcomes and stable facial soft tissues. The risk of mucosal recession was low, with only one patient showing minor recession of the facial mucosa. These encouraging results need to be confirmed with a 5‐year follow‐up examination.     

Effect of Flapless Surgery on Single‐Tooth Implants in the Esthetic Zone: A Randomized Clinical Trial

Background: Implant therapy is a highly predictable treatment option; however, insufficient data exist to show whether flapless implant surgery provides better esthetic outcomes and less bone loss than implant surgery with a flap approach. Methods: In this randomized, controlled study comparing the flapless and traditional flap protocol for implant placement, 24 patients received a single implant in the anterior maxillary region. A cone beam computed tomography–aided surgical guide was used for implant placement surgery for both groups. Implants were restored using a one‐piece, screw‐retained ceramic crown at 3 months. Radiographic and clinical measurements were assessed at baseline (implant placement) and at 3 (crown placement), 6, 9, and 15 months. Clinical parameters evaluated were plaque index, gingival index, papillary index (PPI) (0 = no papilla, 1 = less than half, 2 = more than half but not complete, 3 = complete fill, and 4 = overfill), marginal tissue levels, biotype, width of keratinized tissue, and soft tissue thickness. Results: Implant success rate was 92% in both groups. Mean PPI values for the flap control group and flapless test group were 2.38 ± 0.51 versus 2.31 ± 0.48 at crown placement (P = 0.68) and 2.52 ± 0.52 versus 2.64 ± 0.54 at 15 months (P = 0.42), respectively. PPI increased over time in both groups, although the flapless group had a significantly larger change in PPI from crown placement to 6 and 9 months (P <0.01). Crestal bone levels in the flap group were more apical in relation to the implant platform than those in the flapless group for the duration of the study. No differences among groups were noted for all other measurements. Conclusions: Both flapless and flap implant placement protocols resulted in high success rates. A flapless protocol may provide a better short‐term esthetic result, although there appears to be no long‐term advantage.     

The Sociodemographic Characteristics,Periodontal Health Status,and Subgingival Microbiota of Patients With Chronic Periodontitis and Type 2 Diabetes Mellitus: A Case‐Control Study in a Chinese Population

Background: In China, chronic periodontitis (CP) is common in patients with type 2 diabetes mellitus (T2DM). The purpose of this study is to identify the sociodemographic characteristics associated with such patients and to assess the periodontal health status and subgingival microbiota of patients with CP and T2DM (T2DMCP) in the Chinese population. Methods: A total of 150 patients with T2DMCP and 306 patients with CP without any systemic disease completed questionnaires, underwent clinical periodontal examinations and participated in diabetes‐related parameter examinations. Subgingival plaques were obtained to determine the prevalence and amounts of selected oral bacterial species using polymerase chain reaction (PCR) and real‐time PCR, respectively. Results: The income level and mean body mass index (BMI) of the patients with T2DMCP were significantly higher than those of the patients with CP. Additionally, the patients with T2DMCP were more likely to be urban residents, and they had significantly more severe periodontitis than did the patients with CP. In the patients with T2DMCP, the prevalence and amounts of Treponema denticola and Tannerella forsythia were significantly higher than those in the patients with CP. Finally, compared with the patients with CP, the patients with T2DMCP had a significantly lower prevalence and amount of Prevotella intermedia. Conclusions: Compared with the patients with CP, the patients with T2DMCP were more likely to be urban residents and generally had higher incomes, higher mean BMI, and poorer periodontal health status. Higher levels of T. denticola and T. forsythia and lower levels of P. intermedia were identified in the subgingival plaque of the patients with T2DMCP.     

Efficacy of Using PDGF and Xenograft With or Without Collagen Membrane for Bone Regeneration Around Immediate Implants With Induced Dehiscence‐Type Defects: A Microcomputed Tomographic Study in Dogs

Background: Use of collagen membrane (CM) with xenograft and recombinant human platelet‐derived growth factor (rhPDGF) in guided bone regeneration (GBR) is debatable. The aim of this microcomputed tomographic experiment was to assess the efficacy of using PDGF and xenograft (with or without CM) for GBR around immediate implants with dehiscence defects. Methods: Ten beagle dogs underwent atraumatic bilateral second and fourth premolar extractions from both arches. A standardized dehiscence defect (6 × 3 mm) was created on the buccal bone and immediate implants were placed in distal sockets in each site. Animals were randomly divided into three groups: 1) group 1, xenograft with rhPDGF was placed and covered with CM; 2) group 2, xenograft with rhPDGF was placed over the defects; and 3) group 3, four immediate implants were associated with dehiscence (controls). After 16 weeks, animals were sacrificed and jaw segments were assessed for buccal bone thickness (BBT), buccal bone volume (BBV), vertical bone height (VBH), and bone‐to‐implant contact (BIC) using microcomputed tomography. Results: BBT was higher in group 2 (1.533 ± 0.89 mm) than group 1 (0.745 ± 0.322 mm) (P <0.001) and group 3 (0.257 ± 0.232 mm) (P <0.05). BBV was higher in group 2 (67.87 ± 19.83 mm³) than group 1 (42.47 ± 6.78 mm³) (P <0.05) and group 3 (19.12 ± 4.06 mm³) (P <0.001). VBH was higher in group 2 (6.36 ± 1.37 mm) than group 3 (0.00 ± 0.00 mm) (P <0.001). VBH was higher in group 1 (3.91 ± 2.68 mm) than group 3 (0.00 ± 0.00 mm) (P <0.05). BIC was higher in group 2 (67.25% ± 13.42%) than group 1 (36.25% ± 12.78%) (P <0.05) and group 3 (30.25% ± 7.27%) (P <0.01). Conclusion: GBR around immediate implants with dehiscence defects using PDGF and xenograft alone resulted in higher BBT, BBV, VBH, and BIC than when performed in combination with CM.     

Treatment outcome of immediate,early and conventional single‐tooth implants in the aesthetic zone: a systematic review to survival,bone level,soft‐tissue,aesthetics and patient satisfaction

Aim: This study evaluated, through a systematic review of the literature, the outcome of single‐implant restorations in the aesthetic zone with natural adjacent teeth, thereby addressing immediate, early and conventional implant approaches. Material and Methods: MEDLINE (1950–2008), EMBASE (1966–2008), and CENTRAL (1800–2008) were searched to identify eligible studies. Two reviewers independently assessed the methodological quality using specific study‐design‐related assessment forms. Results: Out of 86 primarily selected articles, 19 studies fulfilled the inclusion criteria. A meta‐analysis showed an overall survival rate of 95.5% [95% confidence interval: (93.0–97.1)] after 1 year. A stratified meta‐analysis revealed no differences in survival between immediate, early and conventional implant strategies. Little marginal peri‐implant bone resorption was found together with low incidence of biological and technical complications. No significant differences in outcome measures were reported in clinical trials comparing immediate, early or conventional implant strategies. Conclusion: The included literature suggested that promising short‐term results could be achieved for immediate, early and conventional single‐implants in the aesthetic zone. However, important parameters as aesthetic outcome, soft‐tissue aspects, and patient satisfaction were clearly underexposed. The question whether immediate and early single‐implant therapies would result in better treatment outcomes remained inconclusive due to lack of well‐designed controlled clinical studies.     

Long‐Term Stability of Contour Augmentation With Early Implant Placement Following Single Tooth Extraction in the Esthetic Zone: A Prospective,Cross‐Sectional Study in 41 Patients With a 5‐ to 9‐Year Follow‐Up

Background: Early implant placement with simultaneous contour augmentation is documented with short‐ and medium‐term studies. The long‐term stability of contour augmentation is uncertain. Methods: In this prospective, cross‐sectional study, 41 patients with an implant‐borne single crown were examined twice, in 2006 and 2010. Clinical, radiologic, and esthetic parameters were assessed at both examinations. In addition, a cone beam computed tomographic (CBCT) image was obtained during the second examination to assess the dimensions of the facial bone wall. Results: All 41 implants demonstrated ankylotic stability without signs of peri‐implant infection at both examinations. The clinical parameters remained stable over time. Satisfactory esthetic outcomes were noted, as assessed by the pink and white esthetic score (PES/WES) indices. Overall, the PES scores were slightly higher than the WES scores. None of the implants developed mucosal recession over time, as confirmed by values of the distance between implant shoulder and mucosal margin and cast measurements. The periapical radiographs yielded stable peri‐implant bone levels, with a mean distance between implant shoulder and first visible bone‐implant contact value of 2.18 mm. The CBCT analysis demonstrated a mean thickness of the facial bone wall ≈2.2 mm. In two implants (4.9%) no facial bone wall was detectable radiographically. Conclusions: This prospective cross‐sectional study demonstrates stable peri‐implant hard and soft tissues for all 41 implants examined and satisfactory esthetic outcomes overall. The follow‐up of 5 to 9 years confirmed again that the risk for mucosal recession is low with early implant placement. In addition, contour augmentation with guided bone regeneration was able to establish and maintain a facial bone wall in 95% of patients.