Implant Failure Predictors in the Posterior Maxilla: A Retrospective Study of 273 Consecutive Implants

Background: The goal of this study was to retrospectively analyze a cohort of 136 patients who underwent dental implant placement in the posterior maxilla at the University of Connecticut Health Center to assess and identify predictors for implant failure in the posterior maxilla. Methods: Data were retrieved from patient charts to identify subjects older than 21 years of age who received dental implant(s) in the posterior maxilla. Patients without a postoperative baseline radiograph were excluded. A recall radiograph was taken 3 to 6 months after implant placement. If there was no recall radiograph, the subject was contacted for a recall visit that included a clinical evaluation and radiographs to determine the implant status. Based on a univariate screening, variables considered potential implant failure predictors included gender, diabetes, smoking, implant length, implant diameter, membrane use, sinus-elevation technique, and surgical complications. These parameters were further assessed, and a multivariable logistic regression was performed with implant failure as a dependant variable. All tests of significance were evaluated at the 0.05 error level. Results: Two hundred seventy-three implants were placed in the posterior maxilla. Fourteen implants failed (early and late failures combined), resulting in a 94.9% overall survival rate. The survival rates for the sinus-elevation group and native bone group were 92.2% and 96.7%, respectively (P = 0.090). Based on the multivariable analysis, sinus floor-elevation procedures were not associated with increased risk for implant failure (P = 0.702). In contrast, smoking and surgical complications had a statistically significant effect on implant failure; the odds ratios for implant failure were 6.4 (P = 0.025) and 8.2 (P = 0.004), respectively. Conclusion: Sinus-elevation procedures with simultaneous or staged implant placement do not increase the risk for implant failure, whereas smoking and surgical complications markedly increase the risk for implant failure.

Cryopreservation and autotransplantation of human ovarian tissue prior to cytotoxic therapy--a technique in its infancy but already successful in fertility preservation

Increasing survival rates in young cancer patients, new reproductive techniques and the growing interest in quality of life after gonadotoxic cancer therapies have placed fertility preservation as an important issue to oncologists, fertility specialists and patients. Several techniques are now available for fertility preservation in these patients. A new promising method is cryopreservation and transplantation of ovarian cortex. Ovarian tissue can be extracted by laparoscopy without any significant delay of gonadotoxic therapy. The tissue can be cryopreserved by specialised centres of reproductive medicine and transplanted in case the women experience premature ovarian failure (POF). This review summarises the European expertise on cryopreservation and transplantation of ovarian tissue, following around 30 reported transplantations globally, resulting in six live births and several ongoing pregnancies. It emphasises that fertility preservation by the cryopreservation of ovarian tissue is a new but already a successful clinical option, which can be considered for selected cancer patients.

[Follow-up after malignant tumours of the uterus (cancer of the uterine corpus / cervical cancer)]

Malignant uterine tumours can affect the corpus or the cervix. The endometrial carcinoma with its different histological subtypes counts for most of the malignomas of the uterine body. But the rare category of uterine sarcomas (carcinosarcomas, leiomyosarcomas as well as endometrial stromal sarcomas) also belongs to this group. Cervical cancer presents an own entitity, regarding both histology and therapeutic options. Endometrial cancer is the most common genital malignoma in Northern Europe and North America. Histologically, the endometrial cancer can be subdivided in two groups: type I is hormonal sensitive and well differentiated, type II represents an undifferenciated aggressive tumour with poor prognosis. In general, the patient is elderly. Due to the main symptom - abnormal vaginal bleeding - endometrial cancer is detected in an early stage in about 75% of all patients. First choice in therapy is stage related surgery. Follow-up schemes have not proved yet to improve survival, therefore clear guidelines are missing. National and international groups recommend regular follow-up visits to detect the early vaginal vault relapse which is curable. Cervical cancer is mainly a squamous cell carcinoma and oncogenic Human Papilloma Virus (HPV) associated. Surgery is only indicated up to stage IIA, advanced stages should be treated by radio-chemotherapy. Several studies have shown that follow-up visits can improve survival rates. Intention is the detection of the curable local relapse.

[Diagnostics of autoimmune diseases]

Autoantibodies play a key role in diagnostic laboratories as markers of autoimmune diseases. In addition to their role as markers they mediate diverse effects in vivo. Autoantibodies with protective effect have been described. Natural protective IgM autoantibodies against tumour-antigens of malignant cells or their precursors may contribute to increased survival rates of carcinoma patients. In a mouse model of systemic lupus erythematosus it has been shown that anti-dsDNA IgM autoantibodies protect from glomerular damage. In contrast, a direct pathogenic role of autoantibodies has been well established e.g. in myasthenia gravis or in Goodpasture syndrome. Similarly autoantibodies against SSA Ro52 are detrimental in neonatal lupus erythematosus with congenital heart block. Moreover, putatively protective autoantibodies may become pathogenic during the course of the disease such as the onconeuronal autoantibodies whose pathogenicity depends on their compartmentalisation. In patients with paraneoplastic syndromes tumour cells express proteins that are also naturally present in the brain. Anti-tumour autoantibodies which temporarily suppress tumour growth can provoke an autoimmune attack on neurons once having crossed the blood-brain barrier and cause specific neurological symptoms. Only a restricted number of autoantibodies are useful follow-up markers for the effectiveness of treatment in autoimmune diseases. Certain autoantibodies hold prognostic value and appear years or even decades before the diagnosis of disease such as the antimitochondrial antibodies in primary biliary cirrhosis or anti-citrullinated protein (CCP)-antibodies in rheumatoid arthritis. It is crucial to know whether the autoantibodies in question recognise linear or conformational epitopes in order to choose the appropriate detection methods. Indirect immunofluorescence microscopy remains a very useful tool for confirmation of results of commercially available immunoassays and for detection of special and rare autoantibodies that otherwise often remain undetected. Standardisation of autoimmune diagnostics is still underway and requires joint efforts by laboratories, clinicians and industry.

Outcome and quality of life in patients treated for abdominal aortic aneurysms: a single center experience

BACKGROUND: Durability of protection and long-term quality of life (QoL) are critical outcome parameters of abdominal aortic aneurysm (AAA) repair. The aim of the present study was to compare results of endovascular and open aneurysm repair (EVAR and OR) with adjusted standard populations, including stratification for urgency of presentation. METHODS: Retrospective analysis of prospectively collected data of 401 consecutive patients presenting with AAA between January 1998 and December 2002. Cross-sectional follow up was 58 +/- 29 months. Patients were grouped into three cohorts: elective EVAR (n = 68), elective OR (n = 244), and emergency OR (including symptomatic and ruptured AAA, n = 89). Endpoints were perioperative (i.e., 30 days or in-hospital) and late mortality rates, as well as long-term QoL as assessed by the Short Form health survey questionnaire (SF-36). RESULTS: Mean age was lower in the elective OR cohort (66 +/- 10 years) than in the EVAR cohort (72 +/- 7 years; p < .05). Perioperative mortality rates were 4.4%, 0.4%, and 10.1%, for the EVAR, elective OR, and emergency OR cohorts, respectively (p < .05). Corresponding cumulative survival rates after 4 years were 67%, 89%, and 69%, respectively. Long-term QoL SF-36 scores were in all cohorts similar to age- and gender-adjusted standard populations, which score between 85 and 115: 99.6 +/- 35.8 (EVAR), 101.3 +/- 32.4 (elective OR), and 100.4 +/- 36.5 (emergency OR). CONCLUSIONS: Long-term QoL is not permanently impaired after AAA repair, but returns in long-term survivors to what would be expected in a standard population. In this respect, differences were found neither between EVAR and OR, nor between elective and emergency repair. Perioperative mortality rates were highest in patients undergoing emergency OR. The outlook for such patients after the perioperative period, however, was similar to that for patients undergoing elective repair.

[Tumor surveillance after resection of colorectal cancer]

Because recurrent adenocarcinoma of the colon and rectum (CRC) can still be treated with acceptable 5-year survival rates, tumor surveillance plays an important role. Early detection of recurrent disease from CRC allows for effective treatment with intention for cure. This is why, in 2007, an interdisciplinary group modified the popular "FAGAS" criteria, a proposition for surveillance after curative resection of colorectal cancer. Proposed are the 3-monthly follow-up of the tumor marker CEA (carcino embryonic antigen), which, in case of lower sigmoid or rectal cancer, would be completed by rectosigmoidoscopy and endosonography every 6 months. As a major change liver sonography is now proposed to be replaced by annual thoraco-abdominal CT scan. Colonoscopy within the first year after resection has its place in the surveillance due to a high rate of metachronous secondary tumors missed in the initial endoscopy. Once completed it needs not to be repeated for at least 3 years. Only in cases where early stage CRC was been completely resected no schematic surveillance must take place.

Cladophialophora bantiana: a rare cause of fungal brain abscess. Clinical aspects and new therapeutic options

Black molds or dematiaceous fungi are rare etiologic agents of intracerebral abscesses and such infections carry a high mortality of up to 70% despite combined surgical and antifungal therapy. While the growing use of immunosuppressive therapies and organ transplantation have caused an increase in the incidence of rare fungal cerebral infections, occurrence in immunocompetent hosts is also possible. We describe a 60-year-old female patient with a cerebral abscess caused by Cladophialophora bantiana. The case illustrates the clinical and radiological similarities between glioblastomas and brain abscesses and emphasizes the need to perform histological and microbiological studies prior to the initiation of any form of therapy. Long-term survival from cerebral black mold abscesses has been reported only when complete surgical resection was possible. The recommended antifungal treatment involves the use of amphotericin B combined with a triazole and, if possible, flucytosine. Highly-active new generation triazole antifungal compounds (voriconazole or posaconazole) are likely to offer improved survival rates for patients with rare mold infections. In particular, posaconazole could be a new therapeutic option given its better tolerance, lower toxicity and fewer drug-drug interactions. We discuss clinical, microbiological and practical pharmacological aspects and review current and evolving treatment options.

Computer technology applications in surgical implant dentistry: a systematic review

PURPOSE: To assess the literature on accuracy and clinical performance of computer technology applications in surgical implant dentistry. MATERIALS AND METHODS: Electronic and manual literature searches were conducted to collect information about (1) the accuracy and (2) clinical performance of computer-assisted implant systems. Meta-regression analysis was performed for summarizing the accuracy studies. Failure/complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 12-month proportions. RESULTS: Twenty-nine different image guidance systems were included. From 2,827 articles, 13 clinical and 19 accuracy studies were included in this systematic review. The meta-analysis of the accuracy (19 clinical and preclinical studies) revealed a total mean error of 0.74 mm (maximum of 4.5 mm) at the entry point in the bone and 0.85 mm at the apex (maximum of 7.1 mm). For the 5 included clinical studies (total of 506 implants) using computer-assisted implant dentistry, the mean failure rate was 3.36% (0% to 8.45%) after an observation period of at least 12 months. In 4.6% of the treated cases, intraoperative complications were reported; these included limited interocclusal distances to perform guided implant placement, limited primary implant stability, or need for additional grafting procedures. CONCLUSION: Differing levels and quantity of evidence were available for computer-assisted implant placement, revealing high implant survival rates after only 12 months of observation in different indications and a reasonable level of accuracy. However, future long-term clinical data are necessary to identify clinical indications and to justify additional radiation doses, effort, and costs associated with computer-assisted implant surgery.

A systematic review on the accuracy and the clinical outcome of computer-guided template-based implant dentistry

Introduction: The aim of this systematic review was to analyze the dental literature regarding accuracy and clinical application in computer-guided template-based implant dentistry. Materials and methods: An electronic literature search complemented by manual searching was performed to gather data on accuracy and surgical, biological and prosthetic complications in connection with computer-guided implant treatment. For the assessment of accuracy meta-regression analysis was performed. Complication rates are descriptively summarized. Results: From 3120 titles after the literature search, eight articles met the inclusion criteria regarding accuracy and 10 regarding the clinical performance. Meta-regression analysis revealed a mean deviation at the entry point of 1.07 mm (95% CI: 0.76-1.22 mm) and at the apex of 1.63 mm (95% CI: 1.26-2 mm). No significant differences between the studies were found regarding method of template production or template support and stabilization. Early surgical complications occurred in 9.1%, early prosthetic complications in 18.8% and late prosthetic complications in 12% of the cases. Implant survival rates of 91-100% after an observation time of 12-60 months are reported in six clinical studies with 537 implants mainly restored immediately after flapless implantation procedures. Conclusion: Computer-guided template-based implant placement showed high implant survival rates ranging from 91% to 100%. However, a considerable number of technique-related perioperative complications were observed. Preclinical and clinical studies indicated a reasonable mean accuracy with relatively high maximum deviations. Future research should be directed to increase the number of clinical studies with longer observation periods and to improve the systems in terms of perioperative handling, accuracy and prosthetic complications.

A systematic review of the performance of ceramic and metal implant abutments supporting fixed implant reconstructions

OBJECTIVES: The objective of this systematic review was to assess the 5-year survival rates and incidences of complications associated with ceramic abutments and to compare them with those of metal abutments. METHODS: An electronic Medline search complemented by manual searching was conducted to identify randomized-controlled clinical trials, and prospective and retrospective studies providing information on ceramic and metal abutments with a mean follow-up time of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by three reviewers. Failure rates were analyzed using standard and random-effects Poisson regression models to obtain summary estimates of 5-year survival proportions. RESULTS: Twenty-nine clinical and 22 laboratory studies were selected from an initial yield of 7136 titles and data were extracted. The estimated 5-year survival rate of ceramic abutments was 99.1% [95% confidence interval (CI): 93.8-99.9%] and 97.4% (95% CI: 96-98.3%) for metal abutments. The estimated cumulative incidence of technical complications after 5 years was 6.9% (95% CI: 3.5-13.4%) for ceramic abutments and 15.9% (95% CI: 11.6-21.5%) for metal abutments. Abutment screw loosening was the most frequent technical problem, occurring at an estimated cumulative incidence after 5 years of 5.1% (95% CI: 3.3-7.7%). All-ceramic crowns supported by ceramic abutments exhibited similar annual fracture rates as metal-ceramic crowns supported by metal abutments. The cumulative incidence of biological complications after 5 years was estimated at 5.2% (95% CI: 0.4-52%) for ceramic and 7.7% (95% CI: 4.7-12.5%) for metal abutments. Esthetic complications tended to be more frequent at metal abutments. A meta-analysis of the laboratory data was impossible due to the non-standardized test methods of the studies included. CONCLUSION: The 5-year survival rates estimated from annual failure rates appeared to be similar for ceramic and metal abutments. The information included in this review did not provide evidence for differences of the technical and biological outcomes of ceramic and metal abutments. However, the information for ceramic abutments was limited in the number of studies and abutments analyzed as well as the accrued follow-up time. Standardized methods for the analysis of abutment strength are needed.

Systemic conditions and treatments as risks for implant therapy

PURPOSE: To evaluate whether systemic diseases with/without systemic medication increase the risk of implant failure and therefore diminish success and survival rates of dental implants. MATERIALS AND METHODS: A MEDLINE search was undertaken to find human studies reporting implant survival in subjects treated with osseointegrated dental implants who were diagnosed with at least one of 12 systemic diseases. RESULTS: For most conditions, no studies comparing patients with and without the condition in a controlled setting were found. For most systemic diseases there are only case reports or case series demonstrating that implant placement, integration, and function are possible in affected patients. For diabetes, heterogeneity of the material and the method of reporting data precluded a formal meta-analysis. No unequivocal tendency for subjects with diabetes to have higher failure rates emerged. The data from papers reporting on osteoporotic patients were also heterogeneous. The evidence for an association between osteoporosis and implant failure was low. Nevertheless, some reports now tend to focus on the medication used in osteoporotic patients, with oral bisphosphonates considered a potential risk factor for osteonecrosis of the jaws, rather than osteoporosis as a risk factor for implant success and survival on its own. CONCLUSIONS: The level of evidence indicative of absolute and relative contraindications for implant therapy due to systemic diseases is low. Studies comparing patients with and without the condition in a controlled setting are sparse. Especially for patients with manifest osteoporosis under an oral regime of bisphosphonates, prospective controlled studies are urgently needed.

Clinical and esthetic outcomes of implants placed in postextraction sites

PURPOSE: The aim of this review was to evaluate the clinical outcomes for the different time points of implant placement following tooth extraction. MATERIALS AND METHODS: A PubMed search and a hand search of selected journals were performed to identify clinical studies published in English that reported on outcomes of implants in postextraction sites. Only studies that included 10 or more patients were accepted. For implant success/survival outcomes, only studies with a mean follow-up period of at least 12 months from the time of implant placement were included. The following outcomes were identified: (1) change in peri-implant defect dimension, (2) implant survival and success, and (3) esthetic outcomes. RESULTS AND CONCLUSIONS: Of 1,107 abstracts and 170 full-text articles considered, 91 studies met the inclusion criteria for this review. Bone augmentation procedures are effective in promoting bone fill and defect resolution at implants in postextraction sites, and are more successful with immediate (type 1) and early placement (type 2 and type 3) than with late placement (type 4). The majority of studies reported survival rates of over 95%. Similar survival rates were observed for immediate (type 1) and early (type 2) placement. Recession of the facial mucosal margin is common with immediate (type 1) placement. Risk indicators included a thin tissue biotype, a facial malposition of the implant, and a thin or damaged facial bone wall. Early implant placement (type 2 and type 3) is associated with a lower frequency of mucosal recession compared to immediate placement (type 1).

A systematic review of the clinical performance of CAD/CAM single-tooth restorations

PURPOSE: This systematic review sought to determine the long-term clinical survival rates of single-tooth restorations fabricated with computer-aided design/computer-assisted manufacture (CAD/CAM) technology, as well as the frequency of failures depending on the CAD/CAM system, the type of restoration, the selected material, and the luting agent. MATERIALS AND METHODS: An electronic search from 1985 to 2007 was performed using two databases: Medline/PubMed and Embase. Selected keywords and well-defined inclusion and exclusion criteria guided the search. All articles were first reviewed by title, then by abstract, and subsequently by a full text reading. Data were assessed and extracted by two independent examiners. The pooled results were statistically analyzed and the overall failure rate was calculated by assuming a Poisson-distributed number of events. In addition, reported failures were analyzed by CAD/CAM system, type of restoration, restorative material, and luting agent. RESULTS: From a total of 1,957 single-tooth restorations with a mean exposure time of 7.9 years and 170 failures, the failure rate was 1.75% per year, estimated per 100 restoration years (95% CI: 1.22% to 2.52%). The estimated total survival rate after 5 years of 91.6% (95% CI: 88.2% to 94.1%) was based on random-effects Poisson regression analysis. CONCLUSIONS: Long-term survival rates for CAD/CAM single-tooth Cerec 1, Cerec 2, and Celay restorations appear to be similar to conventional ones. No clinical studies or randomized clinical trials reporting on other CAD/CAM systems currently used in clinical practice and with follow-up reports of 3 or more years were found at the time of the search.

Implant loading protocols for partially edentulous maxillary posterior sites

PURPOSE: To evaluate early and immediate loading of implants in the posterior maxilla and to investigate whether there is a difference in success rates, survival rates, and peri-implant parameters, including marginal bone level changes. MATERIALS AND METHODS: A comprehensive systematic review of the literature was conducted. The selection of publications reporting on human clinical studies was based on predetermined inclusion criteria and was agreed upon by two reviewers. RESULTS: Twelve papers were identified on early loading (two randomized controlled clinical trials [RCTs] and 10 prospective case series studies). Six papers were found on immediate loading (one RCT, four prospective case series, and one retrospective study). CONCLUSIONS: Under certain circumstances it is possible to successfully load dental implants in the posterior maxilla early or immediately after their placement in selected patients. The success rate appears to be technique sensitive, although no study has directly assessed this. A high degree of primary implant stability (high value of insertion torque) and implant surface characteristics play an important role. It is not possible to draw evidence-based conclusions concerning contraindications, threshold values for implant stability, bone quality and quantity needed, or impact of occlusal loading forces. As for the impact of the surgical technique on implant outcome in different bone densities, no studies prove significant superior results with one technique over another. Well-designed RCTs with a large number of patients are necessary to make early/immediate loading protocols in posterior maxilla evidence based, but ethical and practical considerations may limit the real possibility of such studies in the near future.

Randomized controlled trial comparing a variable-thread novel tapered and a standard tapered implant: interim one-year results

STATEMENT OF PROBLEM: A tapered implant with continuously changing threads purported to provide stable tissue support and allow immediate function has been developed. Treatment success and stabilization of supporting tissues over time require documentation. PURPOSE: The purpose of this prospective, randomized, controlled, multicenter study was to evaluate changes in bone level and soft tissue behavior between the novel implant (NobelActive/NA) and a standard tapered implant (NobelReplace Tapered Groovy/NR) with regard to immediate function. MATERIAL AND METHODS: A total of 177 patients randomly allocated to 3 treatment groups (2 different test implant groups: NA Internal (n=117; internal connection) and External (n=82), and 1 standard treatment group, NR (n=126)) received 325 implants. Implants were placed into healed sites, and all but 6 implants were immediately nonocclusally loaded. Clinical and radiographic evaluations of treatment success, crestal bone levels, and soft tissue changes were performed at the time of placement and after 3, 6, and 12 months. Log-Rank test was used to analyze the differences in survival rate. Marginal bone level was compared using the Kruskal-Wallis test and Mann-Whitney U-test (alpha=.05). RESULTS: One-year cumulative survival rates were comparable (96.6% for NA Internal; 96.3% for NA External; 97.6% for NR; P=.852; Log-Rank). Mean (SD) change in bone level was -0.95 mm (1.37) for NA Internal, -0.64 mm (0.97) for NA External, and -0.63 mm (1.18) for NR (P=.589; Kruskal-Wallis). Stable soft tissues and significantly increased papilla scores (P<.001; Wilcoxon signed-rank) were observed for all implant types. CONCLUSIONS: The novel implants showed high survival rates as well as stable bone and soft tissue levels after 1 year, and may be recommended for clinical use, even under immediate function.