Marginal bone loss pattern around hydroxyapatite-coated versus commercially pure titanium implants after up to 12 years of follow-up

PURPOSE: The purpose of this study was to compare the marginal bone loss (MBL), complications, and 12-year survival rates of commercially pure titanium (cpTi) and hydroxyapatite (HA)-coated implants placed in the maxilla. MATERIALS AND METHODS: The study group consisted of 120 patients (77 women, 43 men) treated from 1988 to 1997. A total of 388 implants (156 cpTi and 232 HA-coated) were placed in the maxilla. There were 126 immediate (32.5%) and 262 (67.5%) nonimmediate implants. Patients were evaluated annually. Mean follow-up was 60 +/- 32.3 months. MBL was measured on radiographs using the implant threads as the dimensional reference. MBL, complications, and 12-year survival and success rates were correlated with implant coating, time of implantation, implant dimensions, and position in arch. RESULTS: Total mean MBL was 1.07 +/- 2.16 mm. MBL was significantly lower with cpTi implants (0.55 +/- 1.04 mm) compared to HA-coated implants (1.51 +/- 2.71 mm) (P < .001). No statistical difference in regard to MBL was found between immediate and nonimmediate implants (0.86 +/- 1.8 mm vs 1.16 +/- 2.3 mm). The total 12-year survival rate was 91.4%. HA-coated implants had a significantly higher 12-year survival rate than cpTi implants (93.2% vs 89%; P < .03). Nonimmediate implants had a significantly higher failure rate (8.2%) than the immediate implants (1.3%) (P < .009). No correlation was found between type of implant coating and late implant failure. DISCUSSION: Immediate implants can serve as a predictable option, providing higher survival and success rates. HA-coated implants tended to fail less during the surgical phase, but had higher mean MBL compared to cpTi implants. CONCLUSIONS: HA-coated implants had greater MBL than cpTi implants but a higher 12-year survival rate. Immediate implants had a lower failure rate than the nonimmediate implants in this study population.     

Private practice results of screw-type tapered implants: survival and evaluation of risk factors

PURPOSE: The aims of this study were to examine the long-term survival and the prosthetic treatment outcome of screw-type, tapered implants placed in a private practice setting and to explore potential risk factors of implant failures. MATERIALS AND METHODS: In this retrospective analysis of patients treated with endosseous screw-type tapered implants, data relative to implant placement and failure, implant length, location, prosthetic treatment, medical history, smoking habits, and oral health behavior were gathered by chart review and questionnaire. An oral examination was also conducted. Cumulative survival rates were estimated through Kaplan-Meier methods. Comparisons between subgroups of patients were made using the log-rank statistical test. The association between several factors and implant failures was analyzed using Cox regression analyses (random and dependent models). Differences were considered significant when P < .05. RESULTS: The survival rate of 663 implants placed in 159 patients (65 men, 94 women; 80.7% of 197 eligible patients) was 91.8% after 120 months. Mandibular implants had a higher survival rate than maxillary implants (96% versus 89%, P = .011). The failure rates for implants were 15.0% among current smokers, 9.6% among former smokers, and 3.6% among nonsmokers. The differences between nonsmokers, former smokers, and current smokers were significant (nonsmokers versus former smokers: P = .036, nonsmokers versus current smokers: P < .001, former smokers versus current smokers: P = .003). Only number of years of smoking was significantly associated with an increased risk of implant failures (P = .036 using dependent estimation; P = .004 using independent estimation). The HR increased to 6.6 for patients who had smoked for 45 years. Loosening of prosthetic components were rare (n=12). No fractures of screws or implants were found. DISCUSSION: Higher failure rates for former smokers and a dose-response effect between duration of smoking and implant failure rates suggested that permanent tissue damage from smoking may occur in addition to immediate local and systemic effects. The frequency of prosthetic complications was comparable to other studies. CONCLUSIONS: Screw-type tapered implants placed in a private dental office demonstrated a cumulative survival rate of 91.8%. The relative risk of implant failure increased with the duration of smoking.     

The Effect of Smoking on Early Bone Remodeling on Surface Modified Southern Implants®

Introduction: Smoking affects the survival of turned titanium implants. Although smoking has less impact on the failure rate of rough surface implants, the effect on bone loss on rough surface implants has not been studied yet and may be an important factor in biological stability. Aim: To determine the effect of smoking on early implant failures and bone remodeling around moderately rough implants (Southern Implants®, Southern Implants, Irene, South Africa). Materials and Methods: Three hundred twenty‐nine patient records, containing information on 712 installed implants, were scrutinized retrospectively and periapical radiographs were analyzed for interproximal bone level. Mann‐Whitney U‐test and Fisher's exact test were performed to compare bone level and implant survival in smokers and nonsmokers. Only implants with at least 6 months of function time were analyzed for bone level changes. Results: The overall survival rate was 98.3%. Implants in smokers had a threefold higher failure rate compared with nonsmokers (5/104 = 4.8% vs 7/608 = 1.2%). This was statistically significant on implant level (p = .007) but not on patient level (1/41 vs 7/288, p = .997). Readable radiographs from 363 implants in 169 patients were available with a mean follow‐up of 12 months (SD 5.11; range 6–28). The mean interproximal bone level was 1.36 mm (n = 363; SD 0.41; range 0.48–3.70). Bone levels were independent of jaw location. Sixty implants from 21 smokers lost statistically significantly (p = .001) more bone (mean 1.56; SD 0.53; range 0.75–3.22) than the 303 implants in 148 nonsmokers (mean 1.32 mm; SD 0.38; range 0.48–3.7). The maxilla is especially prone to bone loss compared with the mandible (1.70 mm vs 1.26 mm, p < .001). Conclusion: The Southern Implants® system demonstrated a high absolute survival rate. Although smokers are not more prone to implant loss, more pronounced peri‐implant bone loss was observed, especially in the maxilla. Whether this affects future biological complications remains to be investigated in prospective long‐term studies.     

Effect of Smoking Habits on Accuracy of Implant Placement Using Mucosally Supported Stereolithographic Surgical Guides

Background: Smoking is considered as a factor for implant survival and peri‐implant bone loss of dental implants. Several studies revealed the negative effect of smoking on osseointegration and its dose‐related effect. Purpose: To evaluate the effect of smoking habits on accuracy of implant placement using mucosally supported stereolithographic surgical guides. Material and Methods: Six OsseoSpeed? implants (Astra Tech AB, Mölndal, Sweden) were inserted into the maxilla in 13 patients. Patients were excluded if they suffered from any systemic disease or if they were actually taking any kind of medication. Software (Mimics® 9.0) was used to fuse images of the virtually planned and actually placed implants, and locations and axes were compared between the nonsmoking and smoking subgroups. As the mucosal biotype could probably influence accuracy data, 12 reference points were defined within each patient to define a mean mucosal thickness value. Results: In the smoking subgroup, 36 implants were placed compared with 42 in the nonsmoking subgroup. Mean coronal deviation was 1.04 mm (range: 0.29–2.45 mm) among the smokers compared with 0.80 mm among the nonsmokers (range: 0.29–1.67 mm). At apical point, mean deviation was 1.26 mm (range: 0.39–3.01 mm) among the smokers compared with 1.02 mm among the nonsmokers (range: 0.32–2.59 mm). Mean angular deviation was 2.64° (range: 0.41–6.81°) among the smokers compared with 2.57° among the nonsmokers (range: 0.16°–8.86°). Significant differences were found when comparing global coronal and apical deviation between the smokers and the nonsmokers (p < .05). Evaluating mucosal thickness, mean value was 3.19 mm (range: 2.39–4.01 mm) among the smokers compared with 2.43 mm among the nonsmokers (range: 1.44–3.03 mm). Conclusions: Statistically significant differences were found when comparing the accuracy of dental implant placement of the smokers with the nonsmokers. Smokers have significant thicker supporting mucosal tissues compared with nonsmokers, which may explain inaccuracy due to less stability of the surgical guide or the scanning prosthesis.     

Implant marginal bone loss in maxillary sinus grafts

PURPOSE: The marginal bone loss (MBL) around implants placed in maxillary sinus grafts was evaluated. MATERIALS AND METHODS: The study consisted of 70 patients who had undergone 81 sinus-graft procedures (total 212 screw-type implants). Complete radiographic records were available for 160 implants, which were used to calculate MBL (follow-up 6 to 56.5 months). Habits (smoking, bruxism), surgical phase parameters (preoperative residual bone, grafting material, implant characteristics, and complications), and prosthetic parameters (crown-implant ratio, marginal fit, and opposite-arch restoration) were recorded for each patient and statistically analyzed regarding MBL. RESULTS: Cumulative survival and overall radiographic success rates were 95.5% and 83.7% for 4.5 years, respectively. Smoking, small implant surface area, and a delayed implantation approach were related to enhanced MBL, with mean MBL values of 0.24 mm/y (P < .011), 0.21 mm/y (P < .031), and 0.31 mm/y (P = .052), respectively. In residual bone of < or =4 mm, the relation to enhanced MBL was stronger (P < .018) for delayed implantation. DISCUSSION: Survival and radiographic success rates compare well with other reports. However, most studies modify success criteria regarding MBL. Smoking may be a primary risk factor regarding implant success. Implants with greater surface area values could compensate for problematic bone characteristics (e.g., in grafted maxillary sinuses). The effect of delayed implantation on MBL was surprising and may prompt simultaneous implantation whenever primary stability can be achieved. CONCLUSIONS: Smoking and implant surface area affected MBL in this patient population. Criteria for long-term implant success should be revised to a standard.     

Relation between smoking and biomarkers of bone resorption associated with dental endosseous implants

The aim of this study was to determine the effects of smoking on pyridinoline concentrations in crevicular fluid collected from around dental implants. Samples of crevicular fluid were collected from 4 sites around each implant and tooth, if present, for a group of 16 patients using methylcellulose strips. Samples were collected from 104 implants and 49 teeth. Eight of the 16 patients were current smokers. Crevicular fluid samples were eluted from methylcellulose strips using phosphate-buffered saline containing 0.1% bovine serum albumin and centrifugation. Pyridinoline was quantified using a competitive enzyme immunoassay. Results showed that there were statistically insignificant differences between the amounts of pyridinoline (mean +/- standard deviation [SD]) around teeth of nonsmokers versus smokers (0.011 +/- 0.003 and 0.014 +/- 0.006 nmol/L, respectively). However, the mean (+/- SD) pyridinoline levels around the implants of nonsmokers (0.012 +/- 0.018 nmol/L) were significantly (P <0.01) less than that of smokers (0.030 +/- 0.006 nmol/L). These results demonstrate that pyridinoline levels are specifically elevated in the crevicular fluid associated with endosseous dental implants of smokers and suggest that smoking may affect implant success in part through alterations in the levels of bone resorption.     

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 the 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 (B. C.). 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 (S. V.) 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 was compared using the log‐rank test. Both nonparametric tests and fixed model analysis were adopted to evaluate bone loss in smokers and nonsmokers. Results: One‐thousand one‐hundred and six implants in 300 patients (186 females; 114 males) with a mean follow‐up of 31 months (SD 7.15; range 24–58) were included. Nineteen implants in 17 patients failed, resulting in an overall survival rate of 98.3% at the implant level and 94.6% at the patient level. After a follow‐up period of 2 years, the cumulative survival rates was 96.7% and 99.1% with the patient and implant as the statistical unit, respectively. Implant survival was significantly higher for nonsmokers compared with 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 0–7.1). Smokers lost significantly more bone compared with 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 (0.25 mm; SD 0.65 vs. 0.22 mm; SD 0.5; 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 a higher risk of experiencing 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.     

Clinical and radiographic evaluations of implants as surveyed crowns for Class I removable partial dentures: A retrospective study

PURPOSEThe purpose of this study was to evaluate survival rates and marginal bone loss (MBL) of implants in IC-RPDs.MATERIALS AND METHODSSeventy implants were placed and used as surveyed crowns in 30 RPDs. The survival rates and MBL around implants based on multiple variables, e.g., position, sex, age, opposing dentitions, splinting, type of used retainer, and first year bone loss, were analyzed. Patient reported outcome measures (PROMs) regarding functional/esthetic improvement after IC-RPD treatment, and complications were also inspected.RESULTSThe 100% implant survival rates were observed, and 60 of those implants showed MBL levels less than 1.5 mm. No significant differences in MBL of implants were observed between implant positions (maxilla vs. mandible; P = .341) and type of used retainers (P = .630). The implant MBL of greater than 0.5 mm at 1 year showed significantly higher MBL after that (P < .001). Splinted implant surveyed crowns showed lower MBL in the maxilla (splinted vs. non-splinted; P = .037). There were significant esthetic/functional improvements observed after treatment, but there were no significant differences in esthetic results based on implant position (maxilla vs. mandible). Implants in mandible showed significantly greater improvement in function than implants in the maxilla (P = .002). Prosthetic complication of IC-RPD was not observed frequently. However, 2 abutment teeth among 60 were failed. The bone loss of abutment teeth was lower than MBL of implants in IC-RPDs (P = .001).CONCLUSIONClass I RPD connected to residual teeth and strategically positioned implants as surveyed crowns can be a viable treatment modality.     

The effect of cigarette smoking and native bone height on dental implants placed immediately in sinuses grafted by hydraulic condensation

The purpose of this study was to determine the effect of cigarette smoking and residual native bone height on the survival of dental implants placed immediately in grafted sinuses. In this retrospective study, 334 subject records were screened, and 75 subjects (155 implants) were included. Data collection based on treatment notes and radiographs included age, sex, smoking status, sinus floor bone height, dental implant information, and implant survival. The survival rates of implants for nonsmokers and smokers at stage-two surgery were 93% and 84%, respectively. After 12 months of functional loading, the survival rates of implants for nonsmokers and smokers were 87% (81 of 93) and 79% (49 of 62), respectively (P < .000). Analysis revealed that the effect of smoking on implant survival is significant when the preoperative bone height is less than 4 mm, with an 82.4% implant survival rate in nonsmokers compared to 60% in smokers (P < .05). Smoking should be considered as a high risk factor when implants are placed immediately in grafted sinuses, particularly in areas of limited bone height.     

The relationship of smoking on peri-implant tissue: A retrospective study

The term “peri-implantitis” is used to describe the formation of deep mucosal pockets around dental implants, inflammation of the peri-implant mucosa, and increased resorption of peri-implant bone. It has been speculated that when left untreated, peri-implantitis can result in implant failure. This retrospective study examines a possible correlation between smoking and the appearance of peri-implantitis. The clinical and radiographic observations of 366 implants in 107 patients who smoke were compared with those of a group of 1000 implants in 314 nonsmoking patients. Despite the retrospective nature of this study, a comparison between the two groups was possible. The mean follow-up period, mean patient age, implant locations, and percentages of fixed partial dentures and overdentures were consistent in both groups. There was no significant difference in the mean maxillary and mandibular hygienic indices between the group of smokers and that of nonsmokers. However, the group of smokers showed a higher score in the bleeding index, the mean peri-implant pocket depth, the degree of peri-implant mucosal inflammation, and radiographically discernible bone resorption mesial and distal to the implant. In the maxilla of the smoking group, these observations were significantly higher than both the mandibular observations for smokers and the maxillary observations of the group of nonsmokers (p < 0.01). No differences between the two groups were observed in the mandible. Aside from the systemic effects of tobacco smoking on the human organism, local cofactors seem to be responsible for the higher incidence of peri-implantitis in smokers and have a particularly negative effect on the maxilla. These findings confirm that smokers treated with dental implants have a greater risk of development of peri-implantitis.     

Healing in smokers versus nonsmokers: survival rates for sinus floor augmentation with simultaneous implant placement

PURPOSE: Evidence suggests that smoking is detrimental to the survival of dental implants placed in grafted maxillary sinuses. Studies have shown that improving bone quantity and quality, using rough-surfaced implants, and practicing good oral hygiene may improve outcomes. In this prospective study, the long-term survival rates of implants placed simultaneously with sinus grafting in smokers and nonsmokers were compared. MATERIALS AND METHODS: Implants with roughened surfaces were immediately placed into maxillary sinus grafts in patients with 1 to 7 mm of residual bone. A total of 2132 simultaneous implants were placed into the grafted sinuses of 226 smokers (627 implants) and 505 nonsmokers (1505 implants). A majority of the patients received a composite graft consisting of 50% autogenous bone. In both smokers and nonsmokers, approximately two thirds of the implants had microtextured surfaces; the remainder had hydroxyapatite-coated surfaces. The implants were restored and monitored during clinical follow-up for up to 9 years. RESULTS: Cumulative survival of implants at 9 years was 97.9%. There were no statistically significant differences in implant failure rates between smokers and nonsmokers. DISCUSSION: Implant survival was believed to depend on the following aspects of the technique used: creation of a large buccal window to allow access to a large recipient site; use of composite grafts consisting of at least 50% autogenous bone; meticulous bone condensation; placement of long implants (i.e., 15 mm); use of implants with hydroxyapatite-coated or microtextured surfaces; use of a membrane to cover the graft and implants; antibiotic use and strict oral hygiene; use of interim implants and restricted use of dentures; and adherence to a smoking cessation protocol.     

Effects of smoking on implant success in grafted maxillary sinuses.

STATEMENT OF THE PROBLEM: Cigarette smoking has been identified as a significant risk factor for dental implant treatment. PURPOSE: This retrospective study evaluated the effect of smoking and the amount of cigarette consumption on the success rates of the implants placed in grafted maxillary sinuses. MATERIAL AND METHODS: Sixty patients (16 smokers and 44 nonsmokers) were evaluated for the effects of smoking on osseointegrated implants placed in 84 grafted maxillary sinuses that contained a total of 228 endosseous root-form implants. Seventy implants were placed in 26 maxillary sinuses in smokers, whereas 158 implants were placed in 58 sinuses in nonsmokers. The number of implant failures and the amount of cigarette consumption were recorded. RESULTS: Of the 228 implants, 205 (89.9%) remained in function, after a mean follow-up period of 41.6 months (2 to 60 months). There was a significantly higher cumulative implant success rate in nonsmokers (82.7%) than in smokers (65.3%) (P =.027). Overall cumulative implant success rate was 76%. There was no correlation between implant failures and the amount of cigarette consumption (P >.99). CONCLUSION: Within the limitations of this study, cigarette smoking appeared to be detrimental to the success of osseointegrated implants in grafted maxillary sinuses regardless of the amount of cigarette consumption.     

Three-year treatment outcomes with three brands of implants placed in the posterior maxilla and mandible of partially edentulous patients

STATEMENT OF PROBLEM: Survival rates of implants in posterior regions vary among clinical studies. Problems occur more often in the posterior segment of the maxilla due to proximity of the maxillary sinus and reduced quality or quantity of alveolar bone. PURPOSE: This clinical study evaluated the treatment outcomes of 3 brands of implants in the posterior maxillae and mandibles of 63 patients. Treatment outcomes of all implants were assessed according to implant type, location, patient gender, periodontal status, and prosthesis type. MATERIAL AND METHODS: A total of 203 implants-105 ITI (ITI), 53 Camlog (CAM), and 45 Frialit (FRI)-were placed in 63 patients (38 women, 25 men). One hundred twelve implants were located in the posterior mandible and 91 in the posterior maxilla. All implants were longer than 10 mm and had a diameter larger than 3.5 mm. Implants in the ITI group were placed in a 1-stage surgery. The CAM and FRI groups were treated with a 2-stage surgical protocol. Implants were not loaded until osseointegration was complete, which was determined clinically and radiographically. At that point, implants were restored with 50 single crowns and 81 fixed partial dentures (FPDs). While 11 FPDs connected implants to natural teeth, 70 FPDs were supported by implants only. Standardized radiographs were made, and clinical parameters were recorded at prosthesis insertion (baseline) and at each recall evaluation (6, 12, 24, and 36 months). Plaque index (PI), sulcus bleeding index (SBI), peri-implant probing depth (PD), and radiographic marginal bone loss (MBL) levels were recorded at baseline, along with any biological and mechanical complications. Repeated-measures ANOVA, Kruskal-Wallis test, Wilcoxon signed rank test, and paired samples tests were used for statistical analysis (alpha=.05). RESULTS: One implant was lost during the osseointegration period in 1 woman due to infection. The cumulative implant treatment outcome was 99.3%. At the 3-year recall, plaque accumulation was significantly higher than baseline scores (P=.01, Wilcoxon signed rank test). Eight percent of the patients presented>2 mm PD at 2-year recall. The influence of observation time was found to be significant for the mean MBL values between groups (P=.001). When MBL values were compared between groups, no significant differences were found. For 1 patient in the FRI group, abutment loosening was observed and both the crown and the abutment were replaced. Patient satisfaction in all groups was high. CONCLUSION: The 3 brands of implants evaluated in this study exhibited similar positive treatment outcomes after 3 years.     

Implant stability and histomorphometry: a correlation study in human cadavers using stepped cylinder implants

The aim of the present study was to determine the correlation between the primary stability of dental implants placed in edentulous maxillae and mandibles, the bone mineral density and different histomorphometric parameters. After assessing the bone mineral density of the implant sites by computed tomography, 48 stepped cylinder screw implants were installed in four unfixed human maxillae and mandibles of recently deceased people who had bequeathed their bodies to the Anatomic Institute I of the University of Erlangen-Nuremberg for medical-scientific research. Peak insertion torque, Periotest values and resonance frequency analysis were assessed. Subsequently, histologic specimens were prepared, and bone-to-implant contact, the trabecular bone pattern factor (TBPf), the density of trabecular bone (BV/TV) and the height of the cortical passage of the implants were determined. The correlation between the different parameters was calculated statistically. The mean resonance frequency analysis values (maxilla 6130.4+/-363.2 Hz, mandible 6424.5+/-236.2 Hz) did not correlate with the Periotest measurements (maxilla 13.1+/-7.2, mandible -7.9+/-2.1) and peak insertion torque values (maxilla 23.8+/-2.2 N cm, mandible 45.0+/-7.9 N cm) (P=0.280 and 0.193, respectively). Again, no correlations could be found between the resonance frequency analysis, the bone mineral density (maxilla 259.2+/-124.8 mg/cm(3), mandible 349.8+/-113.3 mg/cm3), BV/TV (maxilla 19.7+/-8.8%, mandible 34.3+/-6.0%) and the TBPf (maxilla 2.39+/-1.46 mm-1, mandible -0.84+/-3.27 mm-1) (P=0.140 and 0.602, respectively). However, the resonance frequency analysis values did correlate with bone-to-implant contact of the oral aspect of the specimens (maxilla 12.6+/-6.0%, mandible 35.1+/-5.1%) and with the height of the crestal cortical bone penetrated by the implants in the oral aspect of the implant sites (maxilla 2.1+/-0.7 mm, mandible 5.1+/-3.7 mm) (P=0.024 and 0.002, respectively). The Periotest values showed a correlation with the height of the crestal cortical bone penetrated by the implants in the buccal aspect of the implant sites (maxilla 2.5+/-1.2 mm, mandible 5.4+/-1.2 mm) (P=0.015). The resonance frequency analysis revealed more correlations to the histomorphometric parameters than the Periotest measurements. However, it seems that the noninvasive determination of implant stability has to be improved in order to give a more comprehensive prediction of the bone characteristics of the implant site.     

Evaluation of 316 narrow diameter implants followed for 5–10 years: a clinical and radiographic retrospective study

Objectives: Narrow diameter implants (NDIs; diameter >3.75 mm) are useful in replacement of missing incisor teeth and when the bucco‐lingual width of the edentulous crest is insufficient. The present study evaluated the success and survival rates, peri‐implant parameters, mechanical and prosthetic post‐loading complications of NDIs followed over a 10‐year period. Material and methods: Three hundred and sixteen NDIs were inserted into 139 patients and restored with 120 prostheses. Clinical and radiographic assessment data were collected during recall visits. Implant success (SC), cumulative survival rate (CSR), marginal bone loss (MBL), peri‐implant conditions and prosthetic complications were assessed. Cox proportional hazards regression analysis, Kaplan–Meier survival curves with the log‐rank test and life table analysis were used to evaluate the outcome of NDIs within comparable subgroups. MBL and peri‐implant parameters measured annually were further analyzed. Results: The mean follow‐up time was 9.1 years (range: 60–124 months). Twelve implants were lost in the healing phase and two during function. The mean MBL in the maxilla and the mandible was 1.32 ± 0.13 and 1.28 ± 0.3 mm, respectively, after 10 years. SC and CSR were 91.4% and 92.3%, respectively, after 124 months. Smoking and posterior localization were associated with an increased risk of failure. Cement loosening (16.8%) was the most common prosthetic complication. No implants were fractured. Conclusions: NDIs can be used with confidence where a regular diameter implant is not suitable. MBL around NDIs occurred predominantly within 2 years of loading and was minimal thereafter. Further studies are required to clarify the possible risks associated with smoking and posterior placement. To cite this article:
Arιsan V, Bolukbasι N, Ersanlι S, Ozdemir T. Evaluation of 316 narrow diameter implants followed for 5–10 years: a clinical and radiographic retrospective study.
Clin. Oral Impl. Res. 21 , 2010; 296–307.
doi: 10.1111/j.1600‐0501.2009.01840.x     

Immediate versus delayed loading of dental implants placed in fresh extraction sockets in the maxillary esthetic zone: a clinical comparative study

PURPOSE: The aim of this study was to report a clinical comparative assessment of crestal bone level change around single implants in fresh extraction sockets in the esthetic zone of the maxilla either immediately loaded or loaded after a delay. MATERIALS AND METHODS: Forty patients were included in a prospective, randomized study. All patients required 1 tooth extraction (ie, 1 tooth with a hopeless prognosis) and were randomized into either the test group or the control group. Implants were positioned immediately after tooth extraction and were loaded immediately in the test group (20 implants) and after 3 months in the control group (20 implants). The implant site was prepared, with at least 4 mm of sound apical bone below the implant apex, and the coronal margin of the implant was placed at the buccal level of the bone crest. All implants were 13 mm long; 30 implants had a diameter of 5 mm, and 10 had a diameter of 3.75 mm. Radiographic examinations were made at baseline, at 6 months, and at 24 months. To compare the mean values between test and control group, a paired t test was performed (considered statistically significant at P < .05). RESULTS: After a 24-month follow-up period, a cumulative survival rate of 100% was reported for all implants. The control group resulted in a mean mesial bone loss of 1.16 +/- 0.32 mm and a mean distal bone loss of 1.17 +/- 0.41 (mean bone loss, 1.16 +/- 0.51 mm). The test group resulted in a mesial bone loss of 0.93 +/- 0.51 mm and a distal bone loss of 1.1 +/- 0.27 mm (mean bone loss, 1.02 +/- 0.53 mm). No statistically significant difference between control and test groups (P > .05) was found. CONCLUSION: The success rate and radiographic results of immediate restorations of dental implants placed in fresh extraction sockets were comparable to those obtained in delayed loading group.     

Smoking may affect the alveolar process dimensions and radiographic bone density in maxillary extraction sites: a prospective study in humans.

PURPOSE: Loss of ridge width and height typically occur after tooth extraction. This study aimed to investigate whether smoking would effect alveolar ridge remodeling after tooth extraction. MATERIALS AND METHODS: Twenty-one individuals (11 nonsmokers, 10 smokers) requiring a nonmolar extraction in the upper jaw were selected. Radiographs were taken 7 and 180 days after surgery, and the following parameters obtained: alveolar process height (AH), alveolar process width (AW), radiographic bone density in the postextraction socket (BDS), and in the pre-existing bone apically (BDPB). RESULTS: Six months after surgery, intragroup analysis showed that both groups presented a significant reduction in AH, while only smokers had a significant reduction in AW, BDS, and BDPB (P < .05). Furthermore, intergroup analysis showed that smokers presented lower BDS (91.45 pixels +/- 26.62 and 59.53 pixels +/- 19.99, for nonsmokers and smokers, respectively; P = .006) and continued to present lower BDPB (129.34 pixels +/- 42.10 and 89.29 pixels +/- 29.96, for nonsmokers and smokers, respectively; P = .023). Additionally, smokers presented a tendency for lower AH and AW than nonsmokers, but this was not statistically significant. CONCLUSION: Within the limits of the present study, smoking may lead to a more significant dimensional reduction of the residual alveolar ridge and postpone postextraction socket healing.     

The effect of smoking on osseointegrated dental implants. Part I: implant survival

PURPOSE: Recent studies implicate smoking as a significant factor in the failure of dental implants. The purpose of this long-term retrospective study was to evaluate the survival of Br?nemark endosseous dental implants in relation to cigarette smoking. MATERIALS AND METHODS: The sample consisted of 464 consecutively treated completely and partially edentulous patients who had a total of 1852 implants placed between 1979 and 1999, and who were part of a surgical/prosthodontic prospective treatment outcomes study. The effect of cigarette smoking on implant survival in relation to the time of implant failure, gender, age, surgeon, date and site of implant placement, implant length and diameter, prosthesis design, and occlusal loading considerations was assessed in bivariate and multivariate survival analyses. RESULTS: The overall implant failure rate was 7.72%. Patients who were smokers at the time of implant surgery had a significantly higher implant failure rate (23.08%) than nonsmokers (13.33%). Multivariate survival analysis showed early implant failure to be significantly associated with smoking at the time of stage 1 surgery and late implant failure to be significantly associated with a positive smoking history. Short implants and implant placement in the maxilla were additional independent risk factors for implant failure. CONCLUSION: Cigarette smoking should not be an absolute contraindication for implant therapy; however, patients should be informed that they are at a slightly greater risk of implant failure if they smoke during the initial healing phase following implant insertion or if they have a significant smoking history.     

Immediate loading versus immediate provisionalization of maxillary single-tooth replacements: a prospective randomized study with BioComp implants.

PURPOSE: The aim of this prospective randomized study was to evaluate the clinical outcome of immediately loaded solid plasma sprayed (TPS) BioComp (BioComp Industries BV, Vught, The Netherlands) implants versus immediate provisionalized but non-loaded BioComp implants in the anterior and premolar region of the maxilla. MATERIALS AND METHODS: Forty-eight patients (31 females and 17 males) with a mean age of 42.3+/-13.1 years (range 19 to 78 years) were included in the study. Fifty threaded TPS implants were placed and provisionalized within 24 hours after surgery. The patients were randomly assigned to 2 groups. In the immediate loaded (IL) group (n=24) the occlusion of the provisional was designed with normal contacts in centric relation and at lateral excursions, while in the non-immediate loaded (IP) group (n=24) the provisional restoration was adjusted to clear all occlusal contacts or contacts at lateral excursions. Patients were instructed to eat a soft diet and to avoid placing food in the area of the provisional crown during the first 6 weeks. Regular clinical and radiographic controls were performed and the survival rate and implant stability quotient (ISQ) values were evaluated at delivery of the definitive restoration at 6 months. At 1 year, radiographic coronal bone defects and gingival esthetics between the 2 groups were assessed. RESULTS: Of the IL group, 2 fixtures were lost, while 3 implants were lost in the IP group. The failing implants showed increasing mobility at 2 to 3 weeks after insertion, and were removed. The remaining 45 implants were stable at every subsequent follow-up examination, and 6 months after implant placement, ISQ values were measured. The mean ISQ value in the IL group was 63.7+/-5.8 versus 63.2+/-4.3 for the IP group (P=.78). The mean mesial marginal bone loss after 12 months in the IL group was 0.27+/-0.2 mm versus 0.28+/-0.22 mm in the IP group (P=.9). The mean distal marginal bone loss after 12 months in the IL group was 0.19+/-0.15 mm versus 0.2+/-0.11 mm in the IP group (P=.87). All implants of the IL group had an ideal gingival buccal margin, versus 91% of the IP group. Full regeneration of the mesial interdental papilla was observed in 70% of the IL group versus 91% of the IP group, while full regeneration of the distal papilla was observed in 91% of both the IL and IP implants. CONCLUSION: No significant differences in ISQ mean values in radiographic bone loss and gingival esthetics were found between immediate non-loaded provisionalization and immediately loaded BioComp implants in the maxilla.     

Multiple single-tooth implant restorations in the posterior jaws: maintenance of marginal bone levels with reference to the implant-abutment microgap

PURPOSE: The purpose of this study was to measure marginal bone loss from the implant-abutment microgap to the bone crest between multiple freestanding implants functionally loaded for up to 7.5 years in the posterior jaws. MATERIALS AND METHODS: Patients consecutively treated for the replacement of missing posterior teeth were included in the study. Using the implant-abutment interface, which was placed level with the crestal bone as a reference point, standardized follow-up radiographs were obtained to evaluate marginal bone loss. Results were subject to statistical analysis using the Wilcoxon rank sum test and the Wilcoxon signed rank test at the 95% confidence level. Additionally, soft tissue and prosthetic complications were recorded. RESULTS: One hundred seventy-three implants in 54 patients were evaluated. Implants were in function for a mean of 37 months (range, 21 to 91 months). One implant failed, for a survival rate of 99.4%. Overall mean marginal bone loss was 0.65 mm (range, 0.0 to 4.8 mm). For the 80 maxillary and 93 mandibular implants, mean marginal bone loss was 0.56 mm and 0.70 mm, respectively. The frequency of bone loss > or = 1.0 mm was 25.0% in the maxilla and 36.0% in the mandible; 23.1% of maxillary implants and 16.7% of mandibular implants demonstrated no bone loss. No significant differences were observed between men and women or between smokers and nonsmokers. The difference between mesial and distal bone levels was statistically significant (P < .001), with respective means of 0.53 mm and 0.76 mm. Recorded prosthetic complications included cementation failure (17.7%), porcelain fracture (7.2%), and abutment screw loosening (2.2%). CONCLUSIONS: Multiple single-tooth implants placed in the posterior jaws perform extremely well. Furthermore, it is possible to retain bone close to the implant-abutment microgap with certain implant designs.