Melissa Dierens

Long‐term follow‐up of turned single implants placed in periodontally healthy patients after 16–22 years: radiographic and peri‐implant outcome

OBJECTIVES Retrospectively evaluate the survival, radiographic and peri-implant outcome of single turned Brånemark™ implants after at least 16 years. MATERIALS AND METHODS From 134 patients (C-group), 101 could be contacted concerning implant survival and 50 (59 remaining implants) were clinically examined (I-group). Marginal bone level was radiographically measured from the implant-abutment junction at baseline (=within 6 months after abutment connection) and 1-4, 5-8 and 16-22 years post-operatively. Probing depth, gingival and plaque index were measured. Marginal bone-level changes were analyzed using Friedmans and Wilcoxons signed ranks tests. Spearmans correlations between radiographic and clinical parameters were calculated. RESULTS In the C-group, 13 out of 166 implants in 11 out of 134 patients failed (CSR=91.5%). In the I-group (28 males-22 females; mean age 23.9 years at baseline; range 14-57), the mean follow-up was 18.4 years (range 16-22). The mean bone level was 1.7±0.88 mm (range -0.8 to 5) after 16-22 years. Changes in the mean marginal bone level were statistically significant between baseline and the second measuring interval (1-4 years). Thereafter, no significant differences could be demonstrated. The mean interproximal probing depth, gingival and plaque indices were 3.9±1.27 mm, 1.2±0.81 and 0.2±0.48, respectively. Probing depth was moderately correlated with gingival inflammation (r=0.6; P<0.001) but not with bone level (P>0.05). 81.4% of the implants had a bone level ≤2nd thread and 91.5% had a probing depth ≤5 mm. 76.3% had both bone level ≤2nd thread and probing depth ≤5 mm. CONCLUSIONS AND CLINICAL IMPLICATIONS The single turned Brånemark™ implant is a predictable solution with high clinical survival and success rates. In general, a steady-state bone level can be expected over decades, with minimal signs of peri-implant disease. A minority (5%), however, presents with progressive bone loss.

Single Implant Treatment in Healing Versus Healed Sites of the Anterior Maxilla: An Aesthetic Evaluation

PURPOSE The aim was to compare and document in detail the aesthetic outcome of single implant treatment in healing sites (early implant placement) with fully healed sites (conventional implant placement) of the anterior maxilla. MATERIALS AND METHODS A cross-sectional study in patients who had been treated by two periodontists and two prosthodontists in 2006 and 2007 was conducted. Surgical treatment involved standard flap elevation without releasing incisions and restorative procedures included cemented crowns in all patients. Only straightforward single implant treatments using Nobelreplace tapered TiUnite® implants (Nobel Biocare, Göteborg, Sweden) in healing sites (6-8 weeks following tooth extraction) and fully healed sites (≥6 months following tooth extraction) were considered with both neighboring teeth present and without the need for hard and/or soft tissue grafting. The aesthetic outcome was objectively rated using the pink esthetic score (PES) and white esthetic scrore (WES) by a blinded clinician who had not been involved in the treatment. Patients rated aesthetics by means of visual analogue scales. RESULTS Twenty-one out of 22 early and 25/27 conventional implant treatments were available for aesthetic evaluation after on average two and a half years of function (range 17-41 months). There were no significant differences for any of the criteria between the treatment concepts. Overall, papillae were most easy to satisfy, whereas alveolar process and tooth color most difficult. A thin-scalloped biotype was associated with low distal papillae (p=.041) and alveolar process deficiency (p=.039). Twenty-six percent of the cases were aesthetic failures (PES<8 and/or WES<6) and 13% showed an (almost) perfect outcome (PES≥12 and WES≥9). The remainder (61%) demonstrated acceptable aesthetics. There was no significant correlation between objective and subjective ratings. CONCLUSIONS Early and conventional single implant treatment yielded comparable aesthetic outcome. Albeit all treatments had been performed by experienced clinicians and only straightforward cases had been selected, 1 out of 4 cases were aesthetic failures and only a strict minority showed perfection. Research is required on the aesthetic outcome of alternative surgical procedures especially in high-risk patients with a thin-scalloped biotype.

Patient‐centered outcome of immediately loaded implants in the rehabilitation of fully edentulous jaws

INTRODUCTION Edentulism often involves functional, esthetic, phonetic and psychological problems. OBJECTIVES To evaluate patient-centered outcomes of full-arch screw-retained rehabilitation on immediately loaded implants. MATERIAL AND METHODS Fifty patients treated with Astra Tech(TM) implants answered self-administered questionnaires on a visual analogue scale (VAS) 100 mm scale or with multiple-choice or open questions: at baseline, 1 week, 3 or 6 months and 1 year. Changes of VAS in time were analyzed using mixed models for repeated measures, adjusting for gender, age and jaw; comparison of cross-sectional parameters between jaws was performed with the Mann-Whitney U- or chi(2)-test, all at the 0.05 significance level. RESULTS The median calculated general satisfaction score increased from 40.25 (mean=40.9; SD=23.82; range=0-95) at baseline to 98.25 (mean=95.3; SD=6.68; range=74-100) after 1 year. Overall comfort, eating comfort, speaking comfort and perceived esthetics improved significantly within 1 week after surgery and immediate provisionalization. This did not change significantly until the final bridge was installed after 3 months (mandible) or 6 months (maxilla), when a further significant improvement was demonstrated. The most common postoperative complication was swelling, especially in the maxilla. The importance of one-stage surgery and immediate loading was rated very high by patients before treatment, especially in the mandible. The main reason for choosing fixed prosthetics was eating comfort. Phonetics and esthetics were more important in the maxilla than in the mandible. CONCLUSION Immediate full-arch rehabilitation yeilds an instant significant improvement in general patient satisfaction and self-perceived factors related to comfort, function and esthetics. Eating comfort is the main concern for the patient and shows the highest improvement. Postoperative complications are limited and patients considered immediate loading important.

The Influence of Initial Soft Tissue Thickness on Peri‐Implant Bone Remodeling

AIM To elucidate the influence of initial soft tissue thickness on peri-implant bone remodeling. The research hypothesis was that implants installed in patients or at sites with thin mucosal tissues would show increased peri-implant bone loss. MATERIAL AND METHODS 79 edentulous patients were consecutively treated with two non-splinted implants supporting an overdenture in the mandible. During recall-visits, peri-implant health was determined by means of probing pocket depth and the modified plaque/bleeding index. Digital peri-apical radiographs were taken from individual implants. Bone level changes were measured from a reference point (lower border of the smooth implant collar) to the marginal bone-to-implant contact level. The linear mixed-effect model analysis was adopted to analyze the influence of clinical parameters and transmucosal abutment height on peri-implant bone loss. RESULTS 67 patients attended the 1-year and 66 the 2-year recall-visit. Mean bone level changes were 0.89 mm (SD 0.62) and 0.90 mm (SD 0.66), plaque scores 0.82 (SD 0.94) and 0.87 (SD 0.92), bleeding scores 0.46 (SD 0.68) and 0.56 (SD 0.72) and PPD 1.65 mm (SD 0.60) and 1.78 mm (SD 0.59) after 1 year and 2 years respectively. The linear mixed-effect model revealed increasing bone level changes with decreasing abutment heights. Peri-implant bone level changes were significantly higher for implants with abutments of <2 mm (1.17 mm, p < .01; 1.23 mm, p < .01), 2 mm (0.86 mm, p < .01; 1.03 mm, p < .01) or 3 mm (0.38 mm, p = .046; 0.41 mm, p = .044) compared to ≥4 mm-abutments (bone level changes set to zero as reference value) both after 1 year and 2 years and bone level changes were significantly influenced by probing pocket depth (p < .01, p < .01), but not by plaque (p = .31, p = .09) and bleeding scores (p = .30, p = .40). CONCLUSION The present study suggests that implants with lower abutments, reflecting the initial gingival thickness, lose more peri-implant bone, possibly by a re-establishment of the biological width.

Ongoing Crestal Bone Loss around Implants Subjected to Computer-Guided Flapless Surgery and Immediate Loading Using the All-on-4® Concept.

BACKGROUND The All-on-4(®) concept is widely applied for full-arch rehabilitations, using two tilted and two axially loaded implants in order to overcome anatomical constraints. PURPOSE The aim of this study was to assess the survival and individual success of implants immediately loaded with an All-on-4 full-arch screw-retained prosthetic bridge in fully edentulous mandibles or maxillae over up to 3 years. MATERIALS AND METHODS In total, 20 patients with atrophic jaws (9 maxillae, 11 mandibles) were treated with computer-guided flapless surgery and immediately provided with a provisional bridge. The final prosthesis was delivered after 6 months. In total, 80 TiUnite(™) Brånemark implants were placed. Radiographs were taken after surgery and 1 and 3 years later. RESULTS A 3-year survival rate of 100% was seen for all implants, both in lower and in upper jaw. None of the temporary or definite prostheses were lost over the follow-up period of 3 years. After 1 year, the mean bone loss was 1.13 mm (SD 0.94; range -0.1 to 3.8), and after 3 years, it was 1.61 mm (SD 1.40; range 0 to 5). The mean bone loss between the 1-year and 3-year follow-ups was 0.48 mm (SD 0.66; range -1.2 to 3.6). This difference was statistically significant (p < .001), indicative of ongoing bone loss. Twenty-six percent of the implants had bone loss above 1.5 mm after 1 year, but after 3 years, 30% of the implants had already lost more than 1.9 mm. CONCLUSION The implant and prosthetic survival was 100%, and patients benefited from the All-on-4 treatment. However, unacceptable ongoing bone loss was seen in 49.2% of the patients; this may be a warning sign for future problems and needs clinical attention. Overloading and surgery-related aspects need to be investigated as potential explanations.

Prosthetic Survival and Complication Rate of Single Implant Treatment in the Periodontally Healthy Patient after 16 to 22 Years of Follow-Up

BACKGROUND Single implants were introduced in the 1980s, but long-term follow-up is scarce. PURPOSE The study aims to retrospectively investigate the prosthetic survival and complication rates of single implants in periodontally healthy patients after 16-22 years, and to evaluate the influence of different prosthetic procedures. MATERIALS AND METHODS Patients with a single implant were recalled for clinical examination. Prosthetic procedures included single-tooth (ST) and CeraOne (CO) abutments supporting a porcelain-fused-to-metal (PFM), all-ceramic (CER), or gold-acrylic (ACR) crown. Prosthetic survival, success, and occurrence of biological, technical, and aesthetic complications were obtained. Procedures were compared by log-rank tests. RESULTS Fifty patients attended the examination. All implants were functional; however, 15% of abutments and 27% of crowns had been renewed. Replacements (1/4) were related to technical issues whereas the main cause was aesthetics. The abutment cumulative survival rate (CSR) differed significantly between ST-PFM (74%), ST-ACR (0%), and CO reconstructions (97%). The crown CSR was significantly lower for ST-ACR crowns (0%) compared with ST-PFM (68%) and CO (81%). Thirty-nine percent of implants remained complication free throughout the mean 18.5 years. Complications (1/3) required component replacement, and 53% occurred within 5 years after surgery. CONCLUSION Prosthetic survival rates of single implants are encouraging after 16 to 22 years. However, 66% of the patients encountered at least one complication during follow-up.

Long-Term Follow-Up of Turned Single Implants Placed in Periodontally Healthy Patients After 16 to 22 Years: Microbiologic Outcome

BACKGROUND Survival rates in implant dentistry today are high, although late failures do occur for many reasons, including peri-implant infections. The primary objective of this study is to investigate microbiota around single turned implants after 16 to 22 years. Secondary objectives are to compare teeth and implants and to correlate microbiologic, radiographic, and clinical parameters. METHODS A total of 46 patients with single implants were invited for a clinical examination. Clinical data were collected from implants and contralateral natural teeth. Radiographic bone level was measured around implants. Microbiologic samples were taken from implants, contralateral teeth, and the deepest pocket per quadrant. Samples were analyzed with DNA-DNA hybridization including 40 species. Statistical analysis was performed using Wilcoxon signed-rank tests, McNemar tests, and Spearman correlation coefficients with a 0.05 significance level. RESULTS Mean follow-up was 18.5 years (range 16 to 22 years). Tannerella forsythia (1.5 × 10(5)) and Veillonella parvula (1.02 × 10(5)) showed the highest concentrations around implants and teeth, respectively. Porphyromonas gingivalis, Prevotella intermedia, and T. forsythia were significantly more present around implants than teeth. Mean counts were significantly higher around implants than teeth for Parvimonas micra, P. gingivalis, P. intermedia, T. forsythia, and Treponema denticola. Total DNA count was correlated to interproximal bleeding index (r = 0.409) and interproximal probing depth (r = 0.307). No correlations were present with plaque index or radiographic bone level. CONCLUSIONS In the present study, bacterial counts around single implants in periodontally healthy patients are rather low. Although pathogenic bacteria are present, some in higher numbers around implants than teeth (five of 40), the majority of implants present with healthy peri-implant tissues without progressive bone loss.

Accuracy of optical dental digitizers: an in vitro study.

The aim of this study was to evaluate the accuracy, in terms of trueness and precision, of optical dental scanners. An experimental acrylic resin cast was created and digitized using a microcomputed tomography (microCT) scanner, which served as the reference model. Five polyether impressions were made of the acrylic resin cast to create five stone casts. Each dental digitizer (Imetric, Lava ST, Smart Optics, KaVo Everest) made five scans of the acrylic resin cast and one scan of every stone cast. The scans were superimposed and compared using metrology software. Deviations were calculated between the datasets obtained from the dental digitizers and the microCT scanner (= trueness) and between datasets from the same dental digitizer (= precision). With exception of the Smart Optics scanner, there were no significant differences in trueness for the acrylic resin cast. For the stone casts, however, the Lava ST performed better than Imetric, which did better than the KaVo scanner. The Smart Optics scanner demonstrated the highest deviation. All digitizers demonstrated a significantly higher trueness for the acrylic resin cast compared to the plaster cast, except the Lava ST. The Lava ST was significantly more precise compared to the other scanners. Imetric and Smart Optics also demonstrated a higher level of precision compared to the KaVo scanner. All digitizers demonstrated some degree of error. Stone cast copies are less accurate because of difficulties with scanning the rougher surface or dimensional deformations caused during the production process. For complex, large-span reconstructions, a highly accurate scanner should be selected.

Cost estimation of single‐implant treatment in the periodontally healthy patient after 16–22 years of follow‐up

BACKGROUND Costs for single-implant treatment are mostly described for the initial treatment. Information on the additional cost related to aftercare is scarce. OBJECTIVE To make an estimation of complication costs of single implants in periodontally healthy patients after 16-22 years and to compare costs for various prosthetic designs. MATERIALS AND METHODS Patients with a single implant were recalled for a clinical examination and file investigation. Prosthetic designs included single-tooth (ST) and CeraOne (CO) abutments supporting a porcelain-fused-to-metal (PFM), all-ceramic (CER), or gold-acrylic (ACR) crown. Costs related to failures or technical, biologic, and aesthetic complications were retrieved from patients records. Total and yearly additional complication costs were calculated as a percentage relative to the initial cost. Chair time needed to solve the complication was recorded and prosthetic designs were compared by Kruskal-Wallis tests. RESULTS Fifty patients with 59 surviving implants were clinically investigated. Additional complication costs after a mean follow-up of 18.5 years amounted to 23% (range 0-110%) of the initial treatment cost. In total, 39% of implants presented with no costs, whereas 22% and 8% encountered additional costs over 50% and 75%, respectively. In 2%, the complication costs exceeded the initial cost. The mean yearly additional cost was 1.2% (range 0-6%) and mean complication time per implant was 67 min (range 0-345 min). Differences between prosthetic designs (CO, ST-PFM, ST-ACR) were statistically significant for total cost (P = 0.011), yearly cost (P = 0.023), and time (P = 0.023). Pairwise comparison revealed significant lower costs for CO compared with ST-ACR reconstructions. CONCLUSION Patients should be informed about additional costs related to complications with single implants. The mean additional cost spent on complications was almost one-quarter of the initial treatment price. A majority of implants presented with lower additional costs, whereas the highest complication costs were related to a smaller group with 22% of the implants needing more than half of the initial cost for complication management. Expenses were significantly different for various prosthetic designs.

Long-term clinical outcome of single implants inserted flaplessly or conventionally

BACKGROUND Flapless implant surgery is mostly performed using guided surgical protocols, however, long-term studies on free-handed flapless surgery for single implants are lacking. PURPOSE This prospective study evaluates bone level changes, peri-implant health, and complications of solitary implants placed using a conventional flap (F) or flaplessly (FL) after 6-9 years. MATERIALS AND METHODS Fifty-three single TiUnite Brånemark implants were originally inserted in 49 patients using an one-stage delayed loading protocol with flap (n = 27, F) or flaplessly (n = 26, FL) based on available bone volume and surgeons decision-making. Thirty-six patients with 37 implants participated in the prospective follow-up investigation 6-9 years later whereby survival, bone level changes, peri-implant health, and complications were assessed. RESULTS After 88 months (range 76-107), all implants were survived. For F and FL combined, the overall average radiographic bone level was above the first implant thread, 1.26 mm apical of the implant-abutment junction (SD 1.08; 0-4.9) and statistically comparable. Bone loss from time of loading was 0.49 mm (SD 1.1; -1.3 to 2.8) for F and -0.89 mm (SD 1.0; -2.8 to 0.7) for FL (P < .01), suggesting regrowth of bone in FL due to initial countersinking. One implant (2.7%) had a probing depth above 5 mm. CONCLUSION Free-handed flapless implant surgery for single implants with neighboring teeth is a predictable long-term treatment provided when there is sufficient bone volume.