The International Journal of Oral & Maxillofacial Implants, 2/2021
Seiten: 388-394, Sprache: Englisch
Purpose: The objective of this study was to quantify the probability of implant failure over time from intrinsic patient factors using a population of patients from multiple private practices.
Materials and methods: The records for this retrospective, multicenter cohort study were randomly selected from eight private practices. The primary outcome variable was time to event (implant failure or last known follow-up). The included independent variables were age, sex, diabetes status, smoking status, and arch location. Analyses were performed with Cox proportional hazards on three models: univariate, full multivariate, and systemic factor multivariate. The probability of implant survival at 1, 5, and 10 years was calculated using univariate time-to-event modeling on log-normal distribution with 95% CIs and Cox proportional hazard tests for significance. The Kaplan-Meier survival curve was calculated for patients < 71 years of age.
Results: Eight hundred thirty-five implant-level records from 378 patients were collected for analyses. The mean patient age was 60 years, and 48% were men, 15% reported a history of smoking, and 16% reported having diabetes. The follow-up time was as long as 17 years, with a mean of 23.1 months, and a median of 7 months. The hazard ratio (HR) for implant failure due to sex (HR = 1.18; 95% CI: 0.52 to 2.66), smoking (HR = 1.30; 95% CI: 0.49 to 3.46), diabetes (HR = 1.17; 95% CI: 0.35 to 3.86), and arch location (HR = 2.13 to 3.39) failed to reach the threshold within any Cox proportional hazards model (P > .05).
Conclusion: The implant survival probability for patients ≤ 70 years of age is 86.4% at 10 years in the course of routine private practice by experienced providers. Cautious interpretation of these results is critical, as the effects of known systemic risk factors are likely tempered by effective modifications in clinical decisions and protocols with short- and long-term follow-up maintenance.
Schlagwörter: dentistry, implants, risk, survival
The International Journal of Oral & Maxillofacial Implants, 7/2019
SupplementSeiten: 35-49, Sprache: Englisch
Since their development, dental implants have become one of the most common procedures to rehabilitate patients with single missing teeth or fully edentulous jaws. As implants become more mainstream, determining the factors that affect osseointegration is extremely important. Medical risk factors identified to negatively affect osseointegration include diabetes and osteoporosis. However, other systemic conditions and medications that interfere with wound healing have not been as widely investigated. The aim of this systematic review was to evaluate the effect of systemic disorders including diabetes and osteoporosis on implant osseointegration. The aim was also to evaluate the effect of other diseases, such as neurocognitive diseases, cardiovascular disease, human immunodeficiency virus (HIV), hypothyroidism, rheumatoid arthritis, and medications, such as selective serotonin reuptake inhibitors (SSRIs), proton pump inhibitors (PPIs), and antihypertensives. Although the literature does not demonstrate that diabetes negatively affects implant osseointegration, most studies focus on well-controlled diabetics and the use of prophylactic antibiotics. In addition, studies have shown increased long-term bone and soft tissue complications. For osteoporosis, recent studies and reviews also fail to demonstrate a lower osseointegration rate. However, caution must be exercised in these patients due to the risk for osteonecrosis of the jaws (ONJ), especially in patients with bone malignancies. There is also no direct evidence that patients with HIV, cardiovascular disease, neurologic disorders, hypothyroidism, or rheumatoid arthritis have a decreased rate of implant osseointegration. However, some preliminary evidence suggests that medications such as SSRIs or PPIs may have a negative effect on implant osseointegration. These studies are fairly recent and must be validated with continuous research. Moreover, disease control, concomitant medications, and other comorbidities complicate implant osseointegration and must guide our treatment approaches and clinical guidelines.
Schlagwörter: diabetes, medical risk factors, osseointegration, osteoporosis
The International Journal of Oral & Maxillofacial Implants, 3/2019
Seiten: 708-718, Sprache: Englisch
Purpose: The purpose of this prospective randomized clinical trial was to test the hypothesis that narrow-diameter titanium-zirconium (Ti-Zr) alloy implants with a chemically modified hydrophilic surface are not inferior in regard to crestal bone level change compared to standard-diameter implants with the same implant surface and material.
Materials and Methods: This multicenter study included 50 patients in need of a single tooth replacement in the anterior (canine to canine) or premolar region of the mandible or maxilla. Patients were included if the site could accommodate a 4.1-mm-diameter implant. Implants were temporarily restored at 3 to 4 weeks after placement. Definitive restorations were delivered 4 to 6 months after placement. Patients returned 1 year after implant loading for clinical measurements and radiographic examination. The primary outcome was mean crestal bone level changes measured between implant loading and 12 months postloading. Secondary outcomes included implant success, survival, gingival recession, and patient satisfaction.
Results: Fifty patients were enrolled; 47 completed the study. Twenty-three patients were in the narrow-diameter implant group (test), and 24 patients were in the standard-diameter implant group (control). The success and survival rates at 12 months postloading were 100% for both groups. The change in the mean crestal bone level from implant loading to 12 months postloading around narrowdiameter implants was -0.27 ± 0.34 mm. For the standard-diameter implants, the change was significantly higher at -0.48 ± 0.67 mm (P = .02). No significant difference was found in gingival recession and patient satisfaction.
Conclusion: The results of this prospective randomized clinical trial suggest noninferiority of the narrow- vs standard-diameter Ti-Zr implant. In addition, bone remodeling was less pronounced for the narrow-diameter implants.
Schlagwörter: dental Implant, marginal bone level, prospective study, randomized clinical trial, single implant, soft tissue
The International Journal of Oral & Maxillofacial Implants, 7/2016
Supplement Online OnlySeiten: 16-17, Sprache: Englisch
The International Journal of Oral & Maxillofacial Implants, 7/2016
Supplement Online OnlySeiten: 19-30, Sprache: Englisch
Purpose: Multiple bone augmentation techniques are available to allow implant placement in the atrophic maxilla. However, questions remain, regarding which methods are most predictable and have the best dental implant survival rate (SR) in grafted bone. The aim of this systematic review was to evaluate literature from the last 30 years to determine predictability of bone grafting of the edentulous maxilla for implant placement as well as for implant SR.
Materials and Methods: A systematic review was performed of studies conducted during the period 1980 to 2014, specifically focusing on the edentulous maxilla and bone grafting. Surgical techniques discussed in the publications included were guided bone regeneration (GBR), sinus augmentation, onlay bone grafting, nasal floor grafting, and Le Fort I interpositional grafting. All identified articles were evaluated and screened to meet strict inclusion criteria of at least 10 patients, complete maxillary edentulism, 1-year follow-up, and information regarding implant SR. A total of 974 articles were identified with electronic and manual searches. On further evaluation of the titles and abstracts, 44 articles were excluded. Full texts of the articles that met the inclusion criteria were reviewed, of which 40 articles were included in the systematic review.
Results: For onlay bone grafting, 16 studies were included and analyzed, and the weighted mean implant SR was 85.2%. For the GBR technique, two studies were included, with a reported SR ranging from 96.1% to 100%. For Le Fort I interpositional grafting, 11 studies were included, with a weighted mean SR of 89.6%. For the sinus augmentation technique, 12 studies were investigated and the weighted mean SR was 91.5%. For the combination technique, six studies were analyzed and the weighted mean SR was 93.6%.
Conclusions: All five treatment modalities discussed-onlay bone grafting, GBR, Le Fort I interpositional grafting, maxillary sinus augmentation, and/or nasal floor inlay grafting or the combination approach-can be successfully used to augment edentulous maxillary ridge with high implant SRs.
Schlagwörter: bone augmentation, GBR, Le Fort I interpositional grafting, nasal floor grafting, onlay bone grafting, sinus augmentation
The International Journal of Oral & Maxillofacial Implants, 7/2007
SupplementPubMed-ID: 18437791Seiten: 49-70, Sprache: Englisch
Purpose: A variety of techniques and materials have been used to establish the structural base of osseous tissue for supporting dental implants. The aim of this systematic review was to identify the most successful technique(s) to provide the necessary alveolar bone to place a dental implant and support long-term survival.
Methods: A systematic online review of a main database and manual search of relevant articles from refereed journals were performed between 1980 and 2005. Updates and additions were made from September 2004 to May 2005. The hard tissue augmentation techniques were separated into 2 anatomic sites, the maxillary sinus and alveolar ridge. Within the alveolar ridge augmentation technique, different surgical approaches were identified and categorized, including guided bone regeneration (GBR), onlay/veneer grafting (OVG), combinations of onlay, veneer, interpositional inlay grafting (COG), distraction osteogenesis (DO), ridge splitting (RS), free and vascularized autografts for discontinuity defects (DD), mandibular interpositional grafting (MI), and socket preservation (SP). All identified articles were evaluated and screened by 2 independent reviewers to meet strict inclusion criteria. Articles meeting the inclusion criteria were further evaluated for data extraction. The initial search identified a total of 526 articles from the electronic database and manual search. Of these, 335 articles met the inclusion criteria after a review of the titles and abstracts. From the 335 articles, further review of the full text of the articles produced 90 articles that provided sufficient data for extraction and analysis.
Results: For the maxillary sinus grafting (SG) technique, the results showed a total of 5,128 implants placed, with follow-up times ranging from 12 to 102 months. Implant survival was 92% for implants placed into autogenous and autogenous/composite grafts, 93.3% for implants placed into allogeneic/nonautogenous composite grafts, 81% for implants placed into alloplast and alloplast/xenograft materials, and 95.6% for implants placed into xenograft materials alone. For alveolar ridge augmentation, a total of 2,620 implants were placed, with follow-up ranging from 5 to 74 months. The implant survival rate was 95.5% for GBR, 90.4% for OVG, 94.7% for DO, and 83.8% for COG. Other techniques, such as DD, RS, SP, and MI, were difficult to analyze because of the small sample size and data heterogeneity within and across studies.
Conclusions: The maxillary sinus augmentation procedure has been well documented, and the long-term clinical success/survival (> 5 years) of implants placed, regardless of graft material(s) used, compares favorably to implants placed conventionally, with no grafting procedure, as reported in other systematic reviews. Alveolar ridge augmentation techniques do not have detailed documentation or long-term follow-up studies, with the exception of GBR. However, studies that met the inclusion criteria seemed to be comparable and yielded favorable results in supporting dental implants. The alveolar ridge augmentation procedures may be more technique- and operator-experience-sensitive, and implant survival may be a function of residual bone supporting the dental implant rather than grafted bone. More in-depth, long-term, multicenter studies are required to provide further insight into augmentation procedures to support dental implant survival.
The International Journal of Oral & Maxillofacial Implants, 4/2006
PubMed-ID: 16955603Seiten: 535-542, Sprache: Englisch
Purpose: The collection of autologous platelet-rich plasma (PRP) has demonstrated favorable affects on wound healing in compromised patients. The purpose of this study was to evaluate the expression of PDGF, bFGF, and TGF-b in irradiated and nonirradiated bone in a rabbit tibia model and the ability of PRP to increase growth factor expression when added to autogenous bone graft in a rabbit cranial defect model.
Materials and Methods: Ten New Zealand White rabbit tibiae and calvariae were utilized for this study. Tibiae were irradiated at 60 to 70 cGy and evaluated for expression of PDGF, bFGF, and TGF-b. Rabbit calvariae were also analyzed after grafting with autogenous bone and PRP for determination of growth factor expression.
Results: Decreased expression of PDGF, bFGF, and TGF-b was seen in cortical and cancellous bone samples when irradiated bone was compared to nonirradiated rabbit tibiae. An increase in PDGF, bFGF, and TGF-b expression was detected in cortical autogenous bone grafts with PRP at 1 and 2 months compared to autogenous bone alone.
Discussion: In this study, growth factors, which were decreased in irradiated cortical and cancellous bone, showed increased expression at 1 and 2 months when PRP was added to autogenous bone grafts. Thus, PRP may have potential therapeutic applications when bone grafting is required in patients with reduced bone vascularity, including patients with previous head and neck irradiation, diabetes, and smoking habits.
Conclusions: Decreased expression of PDGF, bFGF, and TGF-b was seen in radiated rabbit tibia as compared to nonirradiated controls, and increased expression of these growth factors was seen in PRP-containing autogenous bone grafts. (Basic Science) (More than 50 references)
Schlagwörter: animal study, bone grafting, cranial defects, growth factors, immunohistochemistry
The International Journal of Oral & Maxillofacial Implants, 4/2005
Seiten: 569-577, Sprache: Englisch
Purpose: To guide treatment planning by analyzing the rates of dental implant failure to determine associated risk factors.
Materials and Methods: All consecutively treated patients from January 1982 until January 2003 were included in a retrospective cohort study, as defined in the hierarchy of evidence for dental implant literature. Data regarding gender, age, implant location, bone quality, bone volume, and medical history were recorded. Correlations between these data and implant survival were calculated to establish relative risk (RR) ratios.
Results: Increasing age was strongly associated with the risk of implant failure. Compared to patients younger than 40 years, patients in the 60-to-79 age group had a significantly higher risk of implant failure (RR = 2.24; P < .05). Gender, hypertension, coronary artery disease, pulmonary disease, steroid therapy, chemotherapy, and not being on hormone replacement therapy for postmenopausal women were not associated with a significant increase in implant failure. Smoking (RR = 1.56), diabetes (RR = 2.75), head and neck radiation (RR = 2.73), and postmenopausal estrogen therapy (RR = 2.55) were correlated with a significantly increased failure rate. Overall, implant failure was 8.16% in the maxilla and 4.93% in the mandible (P < .001).
Discussion: Patients who were over age 60, smoked, had a history of diabetes or head and neck radiation, or were postmenopausal and on hormone replacement therapy experienced significantly increased implant failure compared with healthy patients.
Conclusion: Overall, dental implant failure is low and there are no absolute contraindications to implant placement. Conditions that were found to be correlated with an increased risk of failure should be considered during treatment planning and factored into the informed consent process.
(More than 50 references.)
The International Journal of Oral & Maxillofacial Implants, 1/2004
Seiten: 59-65, Sprache: Englisch
Purpose: Platelet-rich plasma (PRP) is potentially useful as an adjunct to allograft and xenograft materials in oral and maxillofacial bone and implant reconstructive surgery. This study compares bone healing and formation in 4 cranial defects in rabbits grafted with autogenous bone, xenograft, and xenograft with PRP (with a no-graft group as a control).
Materials and Methods: Fifteen New Zealand white rabbits were included in this randomized, blind, prospective pilot study. Four identical 8-mmdiameter defects were created in each rabbit cranium and immediately grafted with the above materials. Five rabbits were evaluated at 1 month, 5 at 2 months, and 5 at 4 months. Radiographs were used to evaluate bone density.
Results: Radiographically, sites at which Bio-Oss, autogenous bone, and Bio-Oss + PRP were grafted showed a significant increase in bone density at 1 month (P = .05 for Bio-Oss, P = .02 for autogenous bone, P = .008 for Bio-Oss + PRP) and at 4 months (P = .02 for Bio-Oss, P = .04 for autogenous bone, P = .05 for Bio-Oss + PRP). Autogenous bone sites (P < .001) and Bio-Oss + PRP sites (P < .001) also showed significant increases at 2 months. Histomorphometrically, autogenous bone sites showed a significantly greater increase than control sites (P = .08 at 1 month, P = .03 at 2 months, P = .01 at 4 months), Bio-Oss sites (P < .001 at all 3 evaluation points), or Bio-Oss + PRP sites (P = .009 at 1 month, P = .02 at 2 months, P = .01 at 4 months). Furthermore, Bio-Oss + PRP sites showed a significantly greater increase in bone area at 1, 2, and 4 months than Bio-Oss alone (P = .003 at 1 month, P = .02 at 2 months, P = .006 at 4 months).
Discussion: Radiographs showed significantly greater bone density at the Bio-Oss, autogenous bone, and Bio-Oss + PRP sites than at control sites at nearly every point in time evaluated; however, clinical significance is difficult to determine, since all materials appeared dense on the radiograph. Histomorphometry showed that the increase in bone area at autogenous sites was significantly greater than that seen with other grafting materials or at the control sites.
Conclusion: This study showed a histomorphometric increase in bone formation with the addition of PRP to Bio-Oss in non-critical-sized defects in the rabbit cranium.
The International Journal of Prosthodontics, 4/2002
Seiten: 325-332, Sprache: Englisch
Purpose: An analysis of retrospective data was conducted to establish the survival rates of osseointegrated implants used to retain orbital, nasal, and auricular prostheses over a 14- year period and to recommend guidelines in the restorative treatment of such facial defects.
Materials and Methods: Included in this study were all patients who received implant-retained prostheses for auricular, nasal, or orbital defects from 1987 to 2001 in the Maxillofacial Clinics at the UCLA and City of Hope Medical Centers. Data were obtained from patient charts. Two methods were used to determine survival rates: (1) the percentage of the total exposed implants that survived was determined, and (2) lifetable analysis was used to calculate cumulative survival rates at different time intervals.
Results: A total of 207 implants were placed in 72 patients, and 182 implants had been uncovered. During the study period, 35 implants failed to integrate, and the survival rate for all exposed implants was 80%. Auricular implants showed the highest survival rate (95%), and orbital implants showed the lowest survival rate (53%). The lifetable analysis demonstrated a cumulative 6-year survival rate of 92% for auricular implants and 87% for piriform/nasal implants. In contrast, the survival rate for orbital implants showed a steady downward trend and reached 59% at 66 months.
Conclusion: It is possible to achieve high survival rates of implants in the auricular and piriform/nasal sites through careful presurgical and radiographic planning. The less favorable long-term survival of implants in the orbital rim, especially at irradiated sites, requires further study.