Implants Placed in Adolescents Followed for Up to 15.5 Years: A Retrospective Case Series.

PURPOSE: To evaluate the clinical outcomes of unsplinted implant-supported single crowns placed in adolescents, ages 10 to 19 years, and followed up from 5 to 15 years. MATERIALS AND METHODS: This retrospective case series evaluated the outcomes of implant-supported single crowns placed in adolescents between June 2002 and January 2015. The patients were treated with locking-taper connection implants under a two-stage rehabilitation technique. The variables assessed included patient identification, age and reason for implant placement, implant dimensions, follow-up time, status at follow-up, and event description. To analyze peri-implant changes, bone crest level relative to the adjacent tooth was measured from periapical radiographs taken after implantation and the latest follow-up. A paired t test was performed to determine initial and follow-up differences, and data are shown as mean and 95% confidence interval. Cumulative Kaplan-Meier survival rates for implants and prostheses were calculated. RESULTS: Twenty-one adolescent patients with ages ranging from 14 to 19 years, mainly 16 to 18 years, received a total of 37 implant-supported single crowns more frequently placed in the anterior maxilla as a result of congenital aplasia and trauma. Mean changes in bone crests were 1.99 (± 0.4) mm at the day of crown insertion and 2.23 (± 0.4) mm at the latest follow-up (average: 10 years; P = .08). No implant was lost during the follow-up period, leading to 100% implant survival. A total of 34 surviving crowns and 3 crown failures at the time of the latest follow-up led to a cumulative survival rate of 70%. The most commonly observed event was loss of proximal contacts and infraocclusion, which were handled chairside by adding resin composite. CONCLUSION: Unsplinted implant-supported single crowns placed in adolescents showed high implant and prosthesis survival rates, with a mean bone crest level increase of approximately 0.23 mm relative to the adjacent teeth.

Histological Analysis of an Implant Retrieved from a ß-Tricalcium Phosphate Graft after 4 Years: A Case Study.

We describe the retrieval of a dental implant device that had been successfully osseointegrated for more than 4 years. After obtaining an informed patient consent, the device was retrieved for retreatment purposes from its position in a ß-tricalcium phosphate (ß-TCP) grafted sinus floor. The sinus floor augmentation, using ß-TCP, had been performed in conjunction with the original implant placement, which in turn enabled the histological evaluation of specific regions of interest that were comprised of either grafted or native bone. Radiographs documented the rehabilitated area before and after grafting. The osteogenic events that occurred during the 4-yr-period depict the interplay of implant, synthetic graft material, and native bone in a dynamic process of osteogenesis, ongoing bone maturation, and remodeling that led to the development of haversian-like bone morphology. Two distinct areas were observed histologically, wherein osteointegration occurred uneventfully in both native bone and areas of grafted bone. Of particular interest was the presence of multiple remodeling sites of lamellar bone that could be seen between the plateaus-healing chambers-in which bone eventually evolved into a haversian cortical-like configuration.

Prospective cohort study of dental implant success rate in patients with AIDS.

BACKGROUND: Oral health care of patients with acquired immune deficiency syndrome (AIDS) due to human immunodeficiency virus (HIV) is a growing area of concern, taking into consideration the increased life expectancy of patients resulting from antiretroviral therapy. There is insufficient literature regarding the impact of dental implants in AIDS patients. This study investigated the long-term clinical outcome of implant placement in patients diagnosed with AIDS. METHODS: This monocentric study included AIDS patients with CD4 <200 cells/µL, age 18 years or older, and a minimum of one edentulous space requiring implant. All patients in the study were undergoing highly active antiretroviral therapy (HAART). HAART includes nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and integrase strand transfer inhibitors (INSTIs). Typical treatment includes two different NTRIs, along with a third drug, either an INSTI, a PI, or an NNRTI. Bicon dental implants were placed in the patients after medical clearance and were followed up for 5 years. Bicon system implants were chosen because of availability and previous experience with this brand. Implant success criteria are defined as implants that had no clinical mobility at uncovering, no radiographic radiolucency, and allowed for loading and abutment placement. Implant success in AIDS patients was measured over a period of 5 years. Descriptive statistics were used. RESULTS: Sixteen adults met the inclusion criteria (12 males and 4 females) with mean CD4 count as 141.25 (sd 35.5). Thirty-three implants were placed in selected patients. Average time to uncovering was 151 days (sd 25 days). Two of the three failures were maxillary implants in the anterior arch, and the third was in the mandibular posterior arch. CONCLUSIONS: The study found a slightly higher failure rate of 10 % in patients with AIDS, compared to widely accepted failure rates in healthy patients at 5-7 %. With the advent of new medical therapies, even AIDS patients should be offered the option of root-formed implants as a viable alternative to fixed and removable prosthetics.

The survival of ultrashort locking-taper implants.

PURPOSE: To evaluate the performance of 5-mm-long implants. MATERIALS AND METHODS: A retrospective cohort study was conducted between January 2008 and December 2009. The sample was composed of patients who had received at least one 5-mm-wide, hydroxyapatite-coated Bicon implant. The outcome variable was implant failure. Descriptive statistics and univariate and multivariate Cox proportional hazards regression models, adjusted for multiple implants in the same patient, were utilized to identify predictors of dental implant failure. RESULTS: Two hundred ninety-one subjects who received 410 locking-taper implants were followed for an average of 20 months. Of these, 211 were ultrashort implants (57 were 5 x 5.0 mm and 154 were 5 x 6.0 mm) and 199 were short implants (5 x 8.0 mm). Three hundred twenty-two implants (93.4%) were restored with single crowns. There was a higher proportion of ultrashort single-tooth implants (94.6%) as compared to short single-tooth implants (92.2%). Nine implants failed, for a cumulative survival rate of 97.5%. Of the failed implants, five were ultrashort (all 5 x 6.0 mm) and four were short. No failures were documented for 5- x 5.0-mm ultrashort implants. There was no statistically significant difference (P = .68) in the Kaplan-Meier survival rates of ultrashort implants (97.6%) and short implants (95.2%). After adjusting for other covariates in a multivariate model, implant length was not associated with implant failure (P = .49). CONCLUSIONS: The survival of ultrashort (5- and 6-mm) implants was comparable to that of short (8-mm) implants.

Factors associated with crestal bone gain on single-tooth locking-taper implants: the effect of nonsteroidal anti-inflammatory drugs.

PURPOSE: To identify factors associated with crestal bone gain around single-tooth implants. MATERIALS AND METHODS: A retrospective cohort study was conducted. More than 90 different local and systemic factors were documented. Descriptive statistics and univariate and multivariate mixed-effects regression models, adjusted for multiple implants in the same patient, were used to identify predictors of crestal bone gain after insertion of definitive restorations. RESULTS: Eighty-one subjects who received 326 Bicon implants were followed for an average of 70.7 months. Eighty-one implants in 46 patients showed varying degrees of apparent bone gain over time. Variables associated with peri-implant bone gain in the first multivariate model were: type of opposing structure, tooth (P = .02); type of restoration, crown cemented on a prefabricated titanium abutment with a spherical base (P = .006); hydroxyapatite coating (P = .0005); implant size 5 x 8 mm (P = .02); and daily intake of nonsteroidal anti-inflammatory drugs (NSAIDs) (P =.04). NSAIDs remained significantly correlated to crestal bone gain in the second multivariate analysis; an implant was significantly more likely to gain bone if the patient was taking NSAIDs daily (P = .02), but this effect was specific to hydroxyapatite-coated implants (P = .01). CONCLUSION: Daily doses of NSAIDs were correlated with a significant increase in crestal bone levels around single-tooth hydroxyapatite-coated implants following crown insertion.

Dentoalveolar reconstructive procedures as a risk factor for implant failure.

PURPOSE: Dentoalveolar reconstructive procedures (DRPs) are commonly used to enhance deficient implant recipient sites. It is unclear, however, if these procedures are independent risk factors for implant failure. The specific aim of this study was to assess the use of DRPs as a risk factor for implant failure. MATERIALS AND METHODS: To address the research aim, we used a retrospective cohort study design and a study sample derived from the population of patients who had one or more implants inserted between May 1992 and July 2000. The main predictor variable was the use of DRPs, such as external or internal sinus lifts, onlay bone grafting, or guided-tissue regeneration with autogenous bone grafts or autogenous bone graft substitutes, to enhance the recipient sites before implant insertion. The major outcome variable was implant failure. Appropriate descriptive, bivariate, and multivariate statistics were computed. RESULTS: The study sample was composed of 677 patients who had 677 implants randomly selected (1 implant per patient) for analysis. The overall 1- and 5-year implant survival rates were 95.2% and 90.2%, respectively. Bivariate analyses revealed 4 factors statistically or nearly statistically associated with implant failure: current tobacco use, implant length, implant staging, and type of prosthesis (P <.15). In the multivariate model, patients with DRPs did not have a statistically significant increased risk for implant failure (odds ratio = 1.4, P =.3). CONCLUSIONS: The results of this study suggest that the use of DRPs to reconstruct deficient implant recipient sites was not an independent risk factor for implant failure in either the unadjusted or adjusted analyses.

Risk factors affecting dental implant survival.

Given the predictability of dental implant success, the attention of the scientific community is moving from descriptions of implant success toward a more detailed analysis of factors associated with implant failure. The purposes of this study were (1) to estimate the 1- and 5-year survival of Bicon dental implants and (2) to identify risk factors associated with implant failure in an objective, statistically valid manner. To address the research purposes, we used a retrospective cohort study design and a study sample composed of patients who had one or more implants placed. The predictor variables were grouped into the following categories: demographic, health status, anatomic, implant fixture-specific, prosthetic, perioperative, and ancillary variables. The major outcome variable of interest was implant failure defined as implant removal. Overall implant survival was estimated using the Kaplan-Meier analysis. Risk factors for implant failure were identified using the Cox proportional hazard regression models. The study sample was composed of 677 patients who had 677 implants randomly selected for analysis. The overall 1- and 5-year survival of the Bicon implant system was 95.2% and 90.2%, respectively. After adjusting for other covariates in a multivariate model, both tobacco use (P = .0004) and single-stage implant placement (P = .01) were statistically associated with an increased risk for failure. The results of these analyses suggest that the overall survival of the Bicon dental implant is comparable with other current implant systems. In addition, after controlling for covariates, we identified 2 exposures associated with implant survival, tobacco use and implant staging. Of interest, both of these exposures are under the clinician's control.