Implant surgery by undergraduate students: preliminary 1-year outcome

Background: The increasing demand for implant treatment requires that dentists are properly informed and trained. However, there is some concern that introducing implant surgery in the undergraduate program would encourage students to perform implant surgery beyond their level of skill. Aim: To evaluate benefits and clinical outcome of an educational undergraduate implant program, including surgery and prosthetics. Methods: All last term undergraduate students received theoretical and preclinical (pig cadaver) courses on the principles of implant surgery. Following careful examination and presurgical/prosthetic planning, the students placed one implant (NanoTite Tapered Certain) with an Encodeo`abutment (Biomet 3i, Palm Beach Gardens, FL, USA), by enlarge in a one-stage surgery. After 3–6 months the crown was restored on an individual abutment. Bone loss was measured on peri-apical radiographs, taken at baseline and 1 year. Patients and students scored a questionnaire, to rate their opinion on a Visual Analogue Scale, ranging from 0 (¼very negative) to 100 (¼very positive). Results: Twenty-one implants were placed (18 maxilla, 3 mandible) in 16 patients (3 male, 13 female), mean age 46 years (range 25–64). Four were light smokers ( < 10 cig/day). Four implants were submerged during healing and three were placed into extraction sockets. All implants reached 35–60Ncm stability. Compared with the planned implants, 52.4% of the placed implants had a different dimension. Overall, the students planned for a shorter implant. After 1 year, mean bone loss was 1.33mm (SD 0.50, range 0–2.10) and no failures had occurred. The patients’ reasons for choosing implant treatment were problems with esthetic appearance (13), eating (7), speaking (2) or broken provisional prosthesis (1). They were informed about implants by dentists (7), family or friends (3), the media (4) or the periodontist (2). They reported minimal postoperative pain (80.4/100), would definitely undergo the treatment again (90.4/100) and advise it to others (91.7%). Overall, students were very positive about the project, but realized that more additional training and education is necessary to perform implant surgery independently. Conclusions and clinical implications: Although the clinical outcome was good, the students realized that implant surgery can be complicated and additional training is needed. The fear for overconfidence seems to be limited. Overall, patients were pleased with the treatment and students thought it was a valuable contribution to their education

Above 15-year follow-up of single machined Brånemark implants

Background: Since the late 1980s dental implants have been used in the indication of single-tooth replacement. Aim: The aim of this study was to evaluate the radiographical and clinical outcome of single-machined Bra°nemark implants with at least 15 years of follow-up. Methods: Fifty-one patients who received 63 single implants between 1987 and 1994 were randomly selected. In this patient group three implants failed (4.8%), leaving 60 implants to be clinically investigated. Mean interproximal probing depth, bleeding and plaque index were measured around each implant. Peri-apical radiographs were compared for marginal bone level between baseline (¼within 6 months after abutment connection) and 2–4 years, 5–8 years and 15–22 years of follow-up. Mean interproximal bone level was measured from the implant shoulder as a reference point. Overall changes in marginal bone level were analyzed with the Friedman test and 2-by-2 comparison between time points was evaluated with the Wilcoxon signed ranks test. Results: The group consisted of 29 males and 22 females with a mean age of 24 years (range 14.7–57.4) at implant placement. Mean follow-up time was 18.5 years (range 15–22). Mean probing depth was 3.9 _ 1.27mm (range 2–10.3). Bleeding and plaque indices were 1.2 _ 0.81 and 0.2 _ 0.48, respectively. Mean bone level after 15–22 years was 1.7 _ 0.88mm (range _0.8 to 5). There was no correlation found between radiographic bone level and probing depth. The Friedman test indicated a statistically significant change in marginal bone level between time points (P < 0.05). Wilcoxon signed ranks test showed a statistically significant difference between baseline and all other time points. After 2–4 years no statistically significant differences could be found. All but one implants (98.3%) were within the currently accepted success criteria corresponding to a maximum accepted bone loss of 4.3mm after 15 years. If one accepts a mean bone level of 2.1mm from the implant shoulder (¼2nd thread), 81.7% of the implants are successful. If a mean interproximal probing depth of 5mm is accepted, 91.7% of the implants are successful. If both these criteria are combined, 76.7% are successful. Conclusions and clinical implications: The machined Bra°nemark implant used as a single-tooth replacement is a predictable solution with high clinical survival and success rates. In general, a steady state bone level can be expected over decades. New criteria for long-term implant success should be determined

Utilizing micro-computed tomography to evaluate bone structure surrounding dental implants: a comparison with histomorphometry

Although histology has proven to be a reliable method to evaluate the ossoeintegration of a dental implant, it is costly, time consuming, destructive, and limited to one or few sections. Microcomputed tomography (µCT) is fast and delivers three-dimensional information, but this technique has not been widely used and validated for histomorphometric parameters yet. This study compared µCT and histomorphometry by means of evaluating their accuracy in determining the bone response to two different implant materials. In total, 32 titanium (Ti) and 16 hydroxyapatite (HA) implants were installed in 16 lop-eared rabbits. After 2 and 4 weeks, the animals were scarified, and the samples retrieved. After embedding, the samples were scanned with µCT and analyzed three-dimensionally for bone area (BA) and bone-implant contact (BIC). Thereafter, all samples were sectioned and stained for histomorphometry. For the Ti implants, the mean BIC was 25.25 and 28.86% after 2 and 4 weeks, respectively, when measured by histomorphometry, while it was 24.11 and 24.53% when measured with µCT. BA was 35.4 and 31.97% after 2 and 4 weeks for histomorphometry and 29.06 and 27.65% for µCT. For the HA implants, the mean BIC was 28.49 and 42.51% after 2 and 4 weeks, respectively, when measured by histomorphometry, while it was 33.74 and 42.19% when measured with µCT. BA was 30.59 and 47.17% after 2 and 4 weeks for histomorphometry and 37.16 and 44.95% for µCT. Direct comparison showed that only the 2 weeks BA for the titanium implants was significantly different between µCT and histology (p = 0.008). Although the technique has its limitations, µCT corresponded well with histomorphometry and should be considered as a tool to evaluate bone structure around implants

The effect of smoking on survival and bone loss of implants with a fluoride-modified surface: a 2-year retrospective analysis of 1106 implants placed in daily practice

Aim: To compare survival and peri-implant bone loss of implants with a fluoride-modified surface in smokers and nonsmokers. Materials and Methods: Patient files of all patients referred for implant treatment from November 2004 to 2007 were scrutinized. All implants were placed by the same experienced surgeon (BC). The only inclusion criterion was a follow-up time of at least 2 years. Implant survival and bone loss were assessed by an external calibrated examiner (SV) comparing digital peri-apical radiographs taken during recall visits with the post-operative ones. Implant success was determined according to the international success criteria (Albrektsson et al. 1986). Survival of implants installed in smokers and nonsmokers were compared using the log-rank test. Both non-parametric tests and fixed model analysis were adopted to evaluate bone loss in smokers and nonsmokers. Results: 1106 implants in 300 patients (186 females; 114 males) with a mean follow-up of 31 months (SD 7.15; range 24-58) were included. 19 implants in 17 patients failed, resulting in an overall survival rate of 98.3% on implant level and 94.6% on patient level. After a follow-up period of 2 years, the CSR was 96.7% and 99.1% with the patient and implant as statistical unit respectively. Implant survival was significantly higher for nonsmokers compared to smokers (implant level p = 0.025; patient level p = 0.017). The overall mean bone loss was 0.34 mm (n = 1076; SD 0.65; range 0.00-7.10). Smokers lost significantly more bone compared to nonsmokers in the maxilla (0.74 mm; SD 1.07 vs 0.33 mm; SD 0.65; p < 0.001), but not in the mandible (0.25mm; SD 0.65 vs 0.22mm; SD 0.50; p = 0.298). Conclusion: The present study is the first to compare peri-implant bone loss in smokers and nonsmokers from the time of implant insertion (baseline) to at least 2 years of follow-up. Implants with a fluoride-modified surface demonstrated a high survival rate and limited bone loss. However, smokers are at higher risk to experience implant failure and more prone to show peri-implant bone loss in the maxilla. Whether this bone loss is predicting future biological complications remains to be evaluated

Disparity in patients' and dentists' satisfaction regarding implant restorative treatment

Background: Cross-arch fixed implant prostheses have a good prognosis. However, information on prosthetic quality and patient’s opinion on treatment outcome is scarce. Aim: The aims of this retrospective study were to describe patient-centered outcomes regarding quality and patient’s opinion of full arch bridges placed on Biomet3i dental implants (Palm Beach Gardens, Fl, USA) and to compare these with the dentist’s opinion. Methods: Patients consecutively treated over the last 4 years with mandibular or maxillary full-arch fixed prostheses on four to seven implants were recalled for an independent quality evaluation and to score patient’s satisfaction. All implants were immediately loaded with a screw-retained metal reinforced acrylic provisional bridge within 48 hours after surgery by one operator. Prosthetic treatments were performed by trainees or staff members. Implant survival, marginal bone level, measured from the abutment-implant interface, quality of implant and prosthetic treatment and patients’ opinion were assessed by means of validated check-lists and OHIP-14 questionnaire. By enlarge, the latter focused on satisfaction and well being. Results: Sxiteen of twenty-two patients attended the examination; 5/120 (4.1%) implants were lost before final reconstruction. During a mean follow-up of 26 (7–48; SD 13.6) months, no further losses occurred, only one provisional bridge needed to be repaired. Mean marginal bone level was 2.1mm (0–3.9; SD 0.7); mean probing pocket depth 3.4mm (2.5–5.5; SD 0.71); 30% of the sites were plaque-free and 11% showed no bleeding. For patients’ opinion see table 1. The clinician rated the prostheses perfect in 37% for design, 50% for fit, 46% for occlusion/articulation and 31% for esthetics. The overall score was perfect in 31%. The mean satisfaction score for the dentist and patient were, respectively, 39% and 72%. There was a significant discrepancy in quality assessment on esthetics and overall score between clinician and patient (P < 0.005 – Wilcoxon signed-rank test). Conclusions and clinical implications: Patients deem their fullarch fixed prostheses on implants as satisfactory and of acceptable quality. Most patients overrated the esthetical aspect and overall score compared with the dentist. Implant and prosthetic failure rates are within acceptable limits after a mean functional loading of 2 years certainly given the fact that immediate loading was performed

Surgical protocol and short-term clinical outcome of immediate placement in molar extraction sockets using a wide body implant

Objectives: Implant placement in molar extraction sockets can be difficult due to complex multi-root anatomy and the lack of predictable primary stability. The aim of this study was to evaluate the outcome of an 8 - 9 mm diameter tapered implant, designed to be placed in molar extraction sockets. Material and methods: Patients treated at least 1 year before with a Max® implant (Southern Implants, Irene, South Africa) were invited for a clinical examination. Variables collected were surgical and prosthetic protocol, implant dimension and smoking habits. Peri-implant bone level was determined on peri-apical radiographs and compared to baseline, being implant insertion. Results: 98 implants had been placed in 89 patients. One implant had failed. Thirty eight patients representing 47 implants (maxilla 26, mandible 21) were available for clinical examination. Mean bone loss was 0.38 mm (SD 0.48; range - 0.50 – 1.95) after a mean follow-up of 20 months (range 12 - 35). Implant success was 97.9%. Around 30 implants, a bone substitute was used to fill the residual space, but this did not affect the bone loss outcome. Bone loss was only significantly different between maxilla and mandible (0.48 mm vs. 0.27 mm) and between the 8 and 9 mm diameter implants (0.23 mm vs. 0.55 mm). A full papilla was present at 71% of the interproximal sites and irrespective of bone loss. Conclusions: The Max® implant demonstrated good primary stability, when placed in molar extraction sockets, with limited bone loss over time

The long-term effect of adapting the vertical position of implants on peri-implant health : a 5-year intra-subject comparison in the edentulous mandible including oral health-related quality of life

Despite high success rates of dental implants, surface exposure may occur as a consequence of biologic width establishment associated with surgery. This prospective split-mouth study evaluated the effect of early implant surface exposure caused by initial bone remodeling on long-term peri-implant bone stability and peri-implant health. Additionally, Oral Health-Related Quality of Life (OHRQoL) was assessed by means of the Oral Health Impact Profile-14 (OHIP-14). Twenty-six patients received two non-splinted implants supporting an overdenture in the mandible by means of locators. One implant was installed equicrestally (control) and the second one was installed subcrestally, taking at least 3 mm soft tissue thickness into account (test). During initial bone remodeling (up to 6 months postoperatively), equicrestal placement yielded 0.68 mm additional surface exposure compared to subcrestal placement (p < 0.001). Afterwards, bone level and peri-implant health were comparable in both treatment conditions and stable up to 5 years. The implant overdenture improved OHRQoL (p < 0.01) and remained unchanged thereafter (p = 0.51). In conclusion, adapting the vertical position of the implant concerning the soft tissue thickness prevents early implant surface exposure caused by initial bone remodeling, but in a well-maintained population, this has no impact on long-term prognosis. The treatment of edentulousness with an implant mandibular overdenture improves OHRQoL