Utilization of a Bovine Xenograft to Achieve Dental Root Coverage: A Pilot Study.

Eight patients with 38 Miller Class I, II, and III gingival recession defects were treated using an acellular bovine dermal matrix graft (Primatrix, Integra) under a coronal positioned flap. There was a significant 2.43-mm reduction in defect depth, 85.96% mean root coverage, and 65.79% complete root coverage at the 6-month follow-up. Patients reported a significant improvement in perceived esthetics as well as trends for reduced dentinal hypersensitivity, minimal postoperative pain, and overall satisfaction with the procedure. The favorable clinical outcomes and oral biocompatibility would benefit from comparative trials to evaluate the material against contemporary grafting techniques.

Consistency of Dental Hygiene Therapy Utilizing Various Dental Hygiene Instrumentation and Its Effect on Peri-implant Health and Survival of Dental Implants: A Retrospective Study.

PURPOSE: The purpose of this retrospective study was to provide practice-based evidence to determine if the consistency of dental hygiene therapy, despite utilizing instrumentation literature that has proven to cause alterations to implant surfaces, affects peri-implant health or survival. MATERIALS AND METHODS: The study sample comprised patients with implant-supported full-arch fixed dental prostheses who were distributed into two groups. The consistent hygiene group patients had dental hygiene therapy at a minimum biannually and were exposed to at least three dental hygiene instrument materials. The inconsistent hygiene group patients had dental hygiene therapy at a minimum once every 3 to 10 years and were exposed to at least three dental hygiene instrument materials. Years of survival free of soft tissue pathology and/or implant failure were estimated. Continuous features were summarized with medians, interquartile ranges (IQRs), and ranges; categorical features were summarized with frequency counts and percentages. RESULTS: Among 48 patients in the consistent hygiene group, 11 patients experienced soft tissue pathology or implant failure at a median of 11.3 years; among 99 patients in the inconsistent hygiene group, 17 patients experienced soft tissue pathology or implant failure at a median of 4.8 years. The survival free of soft tissue pathology or implant failure rate at 5 years was 94% for the consistent hygiene group and 91% for the inconsistent hygiene group. The survival free of soft tissue pathology or implant failure rate at 20 years was 70% for the consistent hygiene group and 79% for the inconsistent hygiene group (P = .91). CONCLUSION: Although no statistical differences were found between the groups, this practice-based evidence suggests more consistent dental hygiene therapy increases the median in years in which soft tissue pathology or implant failure is present.

Evaluation of fracture resistance in aqueous environment of four restorative systems for posterior applications. Part 1.

PURPOSE: The goals of this study were to: (1) establish a range of the performance of four restorative systems for posterior single-tooth crowns under single load to fracture submerged in an aqueous environment, (2) identify restorative system(s) of interest to be examined in the second study phase under sliding contact step-stress fatigue as full-contour anatomically appropriate single posterior tooth restoration(s), (3) establish a range for loading/testing for phase 2. MATERIALS AND METHODS: Forty specimens (n = 10/group) of 2 mm uniform thickness were tested. Group 1: monolithic lithium disilicate IPS e.max Press; group 2: IPS e.max ZirPress, 0.8 mm zirconia core with 1.2 mm pressed veneering porcelain; group 3: IPS e.max ZirPress, 0.4 mm zirconia core with 1.6 mm pressed veneering porcelain; group 4: IPS InLine PoM. Specimens were bonded to a block of polycast acrylic resin on a 30° sloped surface with resin cement. Specimens were axially single loaded to failure while submerged under water. RESULTS: There was a statistically significant difference (p < 0.001) in failure load among the four restorative systems. Lithium disilicate showed a mean failure load similar to mean maximum posterior bite forces (743.1 ± 114.3 N). IPS e.max Zirpress with a 0.4 mm zirconia core exhibited the lowest mean failure load (371.4 ± 123.0 N). CONCLUSION: Fracture resistance of monolithic lithium disilicate in an aqueous environment is promising and requires second phase testing to evaluate the potential of various thicknesses appropriate for posterior single tooth applications. Doubling the IPS e.max Zirpress zirconia core from 0.4 mm to 0.8 mm increased the fracture resistance of this restorative system threefold.

Survival of dental implants in irradiated head and neck cancer patients: a retrospective analysis.

PURPOSE: To study the long-term survival of dental implants placed in irradiated bone in subjects who received radiation for head and neck cancer. MATERIALS AND METHOD: A retrospective chart review was conducted for all patients who received dental implants following radiation treatment for head and neck cancer between May 1, 1987 through July 1, 2008. Only patients irradiated with a radiation dose of 50 Gy or greater and those who received dental implants in the irradiated field after head and neck radiation were included in the study. The associations between implant survival and patient/implant characteristics were estimated by fitting univariate marginal Cox proportional hazards models. RESULTS: A total of 48 patients who had prior head and neck radiation had 271 dental implants placed during May 1987 to July 2008. The estimated survival at 1, 5, and 10 years was 98.9%, 89.9%, and 72.3%, respectively. Implants placed in the maxilla were more likely to fail than implants placed in the mandible (p = .002).There was also a tendency for implants placed in the posterior region to fail compared with those placed in the anterior region (p =.051). CONCLUSION: Dental implants placed in irradiated bone have a greater risk for failure. Survival is significantly influenced by the location of the implant (maxilla or mandible, anterior or posterior).

Survival of turned and roughened dental implants in irradiated head and neck cancer patients: a retrospective analysis.

STATEMENT OF PROBLEM: Dental implants placed into previously radiated fields in survivors of head and neck cancer can demonstrate survival rates that are less than optimal. Understanding this behavior may assist with treatment planning in accordance with expected survival rates in these patients. PURPOSE: The purpose of this study was to compare the survival of implants with turned and roughened surfaces placed in patients who had previously received head and neck radiation, and to identify factors associated with implant failure. MATERIAL AND METHODS: The records of 48 patients who had prior head and neck radiation and had 271 dental implants placed between May 1987 and July 2008 were examined. All of the implants were placed in a previously irradiated field dosed to at least 50 Gy. Implant survival was estimated using the Kaplan-Meier method and univariate Cox models with robust standard errors were fitted to evaluate the association between patient/implant factors and implant failure. RESULTS: There were 62 implants placed in the maxilla (32 roughened, 30 turned) and 209 implants (107 roughened, 102 turned) placed in the mandible. The 5-year implant survival rate for implants placed in the maxilla was 72.6% for turned implants and 87.5% for roughened implants. For implants placed in the mandible, the 5-year survival rate was 91.7% for turned implants and 100% for roughened implants. Among implants with a turned surface, implants were more likely to fail if they were placed in the maxilla (P=.008) and if the diameter was ≤3.75 mm (P=.002). CONCLUSIONS: Implants with turned surfaces were 2.9 times more likely to fail compared to the roughened dental implants, although the difference did not reach statistical significance. For implants with turned surfaces, there was a tendency for implants in the maxilla to fail more frequently compared to the mandible. Implants with turned surfaces had a higher likelihood of failure in the posterior region than in the anterior region. For implants with roughened surface there was no significant association between implant survival and location of the implant, type of bone, or length or diameter of the implant.

Survival of dental implants in native and grafted bone in irradiated head and neck cancer patients: a retrospective analysis.

AIM: To study the long-term survival of dental implants placed in native or grafted bone in irradiated bone in subjects who had received radiation for head and neck cancer. MATERIALS AND METHODS: A retrospective chart review was conducted for all patients who received dental implants following radiation treatment for head and neck cancer between May 1, 1987 and July 1, 2008. Only patients irradiated with a radiation dose of 50 Gy or greater and those who received dental implants in the irradiated field after head and neck radiation were included in the study. The associations between implant survival and patient/implant characteristics were estimated by fitting univariate marginal Cox proportional hazards models. RESULTS: A total of 48 patients who had prior head and neck radiation had 271 dental implants placed during May 1987-July 2008. There was no statistically significant difference between implant failure in native and grafted bone (P=0.76). Survival of implants in grafted bone was 82.3% and 98.1% in maxilla and mandible, respectively, after 3 years. Survival of implants in native bone in maxilla and mandible was 79.8% and 100%, respectively, after 3 years. For implants placed in the native bone, there was a higher likelihood of failure in the maxilla compared to the mandible and there was also a tendency for implants placed in the posterior region to fail compared to those placed in the anterior region. CONCLUSION: There was no significant difference in survival when implants were placed in native or grafted bone in irradiated head and neck cancer patients. For implants placed in native bone, survival was significantly influenced by the location of the implant (maxilla or mandible, anterior or posterior).

A retrospective study of the survival of smooth- and rough-surface dental implants.

PURPOSE: To compare the time-dependent cumulative survival rates of smooth- and rough-surface dental implants. MATERIALS AND METHODS: A retrospective chart review was conducted for two time periods: January 1, 1991, through December 31, 1996, during which smooth-surface implants were used, and January 1, 2001, through December 31, 2005, during which rough-surface implants were used. This study included all implants placed and restored in one institution during the two time frames. Data were collected relative to patient age, gender, implant diameter, implant length, and anatomic location of implants. To facilitate the comparison, implants from the first and second time periods were followed through mid-1998 and mid-2007, respectively. Associations of patient/implant characteristics with implant survival were evaluated using marginal Cox proportional hazards models (adjusted for age and gender) and summarized with hazard ratios and corresponding 95% confidence intervals. RESULTS: A total of 593 patients (322 women and 271 men; mean age, 51.3 +/- 18.5 years) received 2,182 smooth-surface implants between 1991 and 1996, while 905 patients (539 women and 366 men; mean age, 48.2 +/- 17.8 years) received 2,425 rough-surface implants between 2001 and 2005. At 5 years after implant placement, survival rates were 94.0% and 94.5%, respectively, for smooth- and rough-surface implants (difference not significant). Among the smooth implants, implant length

Effect of osteoporotic status on the survival of titanium dental implants.

OBJECTIVES: The aim of this study was to determine whether a diagnosis of osteoporosis affected the survival rate of osseointegrated dental implants. Other variables that were studied were age, arch location of the implant, and smoking status on the effect of dental implant survival. MATERIALS AND METHODS: A retrospective chart review was completed on all women who were 50 years of age or older at the time of dental implant placement at the Mayo Clinic between October 1, 1983, and December 31, 2004. Osteoporotic status was defined on the basis of bone mineral density (BMD) score utilizing World Health Organization criteria. Univariate analyses were performed to evaluate the following independent variables' effect on implant survival: BMD T-score, age, osteoporosis status, arch location of the implant, and smoking status at the time of implant placement. RESULTS: A total of 3,224 implants in 746 female patients 50 years of age or older at the time of implant placement were evaluated. BMD scores within 3 years of implant placement were available for 646 implants (192 patients). In this group, 37 implant failures were noted. The 5-year implant survival rate was 93.8% in the group of patients with BMD scores. In this group of 192 patients, there were 94 (49%) who were not diagnosed with osteopenia or osteoporosis, 57 (29.7%) with a diagnosis of osteopenia, and 41 (21.4%) with a diagnosis of osteoporosis. Patients with a diagnosis of osteoporosis or osteopenia were not significantly more likely to develop implant failure compared to those without such a diagnosis (HR = 1.14, 95% CI = 0.50 to 0.60, P = .76 and HR = 0.98, 95% CI = 0.40 to 2.42, P = .97, respectively). Arch location and BMD score did not have a statistically significant effect on implant survival rates. The only tested variable to demonstrate a significant effect was smoking. Implants in patients who were smokers during the time of implant placement were 2.6 times more likely to fail compared to implants placed in patients who did not smoke (HR = 2.6, 95% CI = 1.20 to 5.63; P = .016). CONCLUSIONS: Based upon the data derived from this retrospective study of 192 women at least 50 years of age at the time of implant placement, the following observations were made: (1) a diagnosis of osteoporosis and osteopenia did not contribute to increased risk of implant failure and (2) implants placed in patients who were smokers at the time of implant placement were 2.6 times more likely to fail than implants placed in nonsmokers. Based on these data, a diagnosis of osteoporosis or osteopenia is not a contraindication to dental implant therapy.

The effects of smoking on the survival of smooth- and rough-surface dental implants.

PURPOSE: To compare the long-term survival rates of smooth- and rough-surface dental implants among smokers and nonsmokers. MATERIALS AND METHODS: A retrospective chart review was conducted for 2 time periods: January 1, 1991, through December 31, 1996, during which smooth-surface implants were utilized, and January 1, 2001, through December 31, 2005, during which rough-surface implants were utilized. This review included all implants placed and restored in 1 institution during the 2 timeframes. Data were specifically collected relative to patient age, gender, smoking status, implant diameter, implant length, and anatomic location of implants. Implants from the first and second time periods were followed through mid-1998 and mid-2007, respectively. Associations of patient/implant characteristics with implant survival were evaluated using marginal Cox proportional hazards models (adjusted for age and gender) and summarized with hazard ratios (HR) and corresponding 95% confidence intervals (CI). RESULTS: A total of 593 patients (322 [54.3%] female; mean [SD] age, 51.3 [18.5] years) received 2,182 smooth-surface implants between 1991 and 1996, while 905 patients (539 [59.6%)] female; mean [SD] age, 48.2 [17.8] years) received 2,425 rough-surface implants between 2001 and 2005. Among the rough-surface implants, smoking was not identified as significantly associated with implant failure (HR = 0.8; 95% CI = 0.3 to 2.1; P = .68). In contrast, smoking was associated with implant failure among the group with smooth-surface implants (HR = 3.1; 95% CI = 1.6 to 5.9; P < .001). Implant anatomic location was not associated with implant survival among patients with rough-surface implants (P = .45) and among nonsmokers with smooth-surface implants (P = .17). However, anatomic location affected the implant survival among smokers with smooth-surface implants (P = .004). In particular, implant survival was the poorest for implants placed in the maxillary posterior areas of smokers. CONCLUSIONS: Based on this retrospective study, the following observations were made: Smoking was identified as a risk factor for implant failure of smooth-surface implants only; among the smokers who received smooth-surface implants, an association was identified between implant failure and location of the implant placement; no association was identified between implant failure and location among the smokers who received rough-surface implants.