A multi-center retrospective assessment of monolithic zirconia restorations on posterior teeth and implants / Una evaluación retrospectiva multicéntrica de restauraciones monolíticas de circonio en dientes posteriores e implantes

Objective: the purpose of this multicenter retrospective study was to report on survival, success, and complication rates in monolithic zirconia restorations on teeth and implants. Materials and Methods: data on 671 monolithic zirconia restorations was collected by five prosthodontists from three different specialty practice centers, including a dental school and two private practice centers. Restorations included single crowns and multiple-unit fixed dental prostheses on teeth and implants in the posterior area (premolar and molars). Follow-up time was up to 62 months. Results: mean follow-up time was 28.1±12.9 months. A total of 671 units, 534 single crowns, and 137 multi-unit restorations. Cumulative survival and success rates at 5 years were 97.4%, and 93.8% respectively. Complications presented in 11 restorations out of 671 and included: decementation, abutment screw loosening, restoration crack, restoration fracture, and tooth fracture. No significant differences were observed between tooth-supported and implant-supported restoration (p=0.42), single crowns and multiple-unit restorations (p=0.07), bruxers and non-bruxers (p=0.57). Patients with group function occlusal scheme had significantly less survival rates (p=0.001). Conclusion: the use of monolithic zirconia for restorations on the posterior teeth and implants seems to be promising as it provides a durable solution with a low rate of complications.

Objetivo: el propósito de este estudio retrospectivo multicéntrico fue informar sobre las tasas de supervivencia, éxito y complicaciones en restauraciones monolíticas de circonio en dientes e implantes. Materiales y Métodos: cinco prostodoncistas recolectaron datos de 671 restauraciones monolíticas de zirconia de tres centros de práctica especializados: una escuela de odontología y dos centros de práctica privados. Las restauraciones incluyeron coronas individuales y prótesis dentales fijas de unidades múltiples en dientes e implantes en el área posterior (premolares y molares). El tiempo de seguimiento fue de hasta 62 meses. Resultados: el tiempo medio de seguimiento fue de 28,1±12,9 meses. Un total de 671 unidades, 534 coronas individuales y 137 restauraciones de unidades múltiples. La supervivencia acumulada y las tasas de éxito a los 5 años fueron del 97,4% y del 93,8%, respectivamente. Las complicaciones se presentaron en 11 restauraciones de 671 e incluyeron: fracaso del cementado, aflojamiento del tornillo del pilar, grieta en la restauración, fractura de restauración y fractura de dientes. No se observaron diferencias significativas entre la restauración con soporte dental y con implante (p=0,42), coronas individuales y restauraciones de unidades múltiples (p=0,07), pacientes con bruxismo y sin bruxismo (p=0,57). Los pacientes con esquema oclusal de función grupal tuvieron tasas de supervivencia significativamente menores (p= 0,0 01). Conclusión: el uso de zirconia monolítica para restauraciones en los dientes posteriores y en implantes parece ser prometedor, ya que proporciona una solución duradera con una baja tasa de complicaciones.

Retrospective Study of Survival of Extraoral Endosseous Craniofacial Implants in Head and Neck Surgery Patients.

PURPOSE: To determine the survival rate of implants placed in different craniofacial locations and factors affecting survival. MATERIALS AND METHODS: This study retrospectively reviewed a consecutive series of patients treated at the Royal Melbourne Hospital who received craniofacial implants for an array of benign and malignant conditions. Implant survival per site and cumulative survival were determined. Surgical and implant variables were assessed using the Kaplan-Meier and Cox Proportional Hazards Models. RESULTS: Fifty-two patients had 156 implants placed to reconstruct the nose, orbit, and ears. A total of 43 implants failed (overall survival: 72.4%) in the orbital (29/63, failure rate: 46%) and auricular sites (14/70, failure rate: 17%). No implants failed in the nasal site (0/9). Three-, 5-, and 10-year cumulative survival was also determined. Independent risk factors for decreased survival included postoperative radiation therapy (P = .005, RR: 3.2, 95% CI: 1.4 to 7.0), implants placed in the orbit (P = .004, RR: 5.0, 95% CI: 1.6 to 15.2), and implants that were not loaded with a prosthesis (P = .007, RR: 2.7, 95% CI: 1.3 to 5.4). CONCLUSION: Failure rates varied according to site in this cohort of patients. A number of independent risk factors affecting implant survival in extraoral sites were identified.

Immediate Replacement of Single Teeth With Immediately Loaded Implants: Retrospective Analysis of a Clinical Case Series.

INTRODUCTION: The purpose of this retrospective analysis of clinical data was to evaluate the predictability of replacing failing single teeth with immediately placed implants loaded via a transitional (provisional) restoration. MATERIALS AND METHODS: Implants were placed immediately at the time of extraction of failing single teeth that met predetermined inclusion criteria. A detailed protocol was followed to enable immediate loading of the implant with the use of prefabricated abutments in combination with transitional restorations. RESULTS: A total of 375 immediate implants had been placed in 274 patients and loaded immediately. With the certainty of 95%, an estimated overall mean survival rate better than 97.6% was observed after a mean observation period of 36 months. The maximum observation period was 142 months. Four implants had been lost in function. CONCLUSION: Immediate loading of immediately placed implants is a possible treatment option that might be predictably and successfully achieved. Implants of adequate primary stability coupled with a range of prefabricated abutments permit function to be achieved using transitional restorations. The preliminary results of this clinical case series are very promising.

Rehabilitation of Full-Mouth Edentulism: Immediate Loading of Implants Inserted With Computer-Guided Flapless Surgery Versus Conventional Dentures: A 5-Year Multicenter Retrospective Analysis and OHIP Questionnaire.

OBJECTIVE: The purpose of this report is to compare satisfaction of patients rehabilitated with full-mouth fixed prostheses using computer-aided flapless implant placement and immediate loading with patients rehabilitated with conventional removable prostheses. MATERIALS AND METHODS: The study included 30 consecutive fully edentulous patients who received 312 implants and 30 matched controls treated with conventional removable prostheses. Mandible and maxilla were treated in the same surgical session with computer-guided flapless approach using NobelGuide protocol. Prefabricated screw-retained fixed prostheses were inserted at the end of surgery. Clinical and radiographic evaluations were assessed at 6, 12, and 36 months. At baseline and 5 years after prostheses delivery, patients answered OHIP-EDENT questionnaire (Oral Health Impact Profile for Edentulous subjects) to assess satisfaction. RESULTS: The implant survival rate was 97.9%, whereas the average marginal bone loss was 1.9 ± 1.3 mm after 3 years. At 6 months, patients showed significantly greater satisfaction with their fixed rehabilitation as compared to conventional dentures. CONCLUSIONS: The results of this study confirm that rehabilitation with a prefabricated fixed prosthesis supported by implants placed with NobelGuide protocol significantly increases the quality of life in fully edentulous patients when compared with complete dentures.

Estabilidade em implantes dentários: análise da frequência de ressonância e torque de inserção / Stability in dental implants: analysis of resonance frequency and insertion torque

As pesquisas clínicas na área da implantodontia apresentam uma grande dificuldade em relação à avaliação da osseointegração e estabilidade dos implantes. Dessa forma, a análise de frequência de ressonância (AFR) têm se tornado uma das principais ferramentas utilizadas, já que oferece, de forma simples e não invasiva, a possibilidade de se monitorar a estabilidade durante todo o período desejado. Outra medida também bastante usada na prática clínica é o torque de inserção dos implantes. No entanto, essa medida é limitada ao trans-cirúrgico e nos fornece unicamente a estabilidade primária dos implantes, o que a torna mais indicada para avaliação da possibilidade de se submeter à carga imediata. Este estudo apresenta como objetivos avaliar, por meio de um estudo transversal, se os valores do coeficiente de estabilidade do implante (ISQ) são similares em diferentes alturas do componente protético e diretamente na plataforma, quando mensurados por meio da AFR e avaliar por meio de uma revisão sistemática e meta-análise a relação entre o torque de inserção e a AFR, investigando se estes dois instrumentos fornecem avaliações similares da estabilidade primária de em um mesmo implante. Para tal, foi realizado um estudo transversal em 31 implantes osseointegrados com plataforma de hexágono externo, com 4.1 mm de diâmetro e comprimento maior ou igual a 10mm e uma revisão sistemática com ensaios clínicos que reportassem valores de ISQ e torque de inserção. Assim, nossos estudos recomendam que explorar e desenvolver a AFR como método de avaliação da estabilidade implantar deve ser uma busca ainda necessária das pesquisas científicas para melhor compreensão do comportamento dos implantes dentários, nos seus diversos momentos e situações na cavidade oral, bem como determinar um bom nível de estabilidade que consequentemente determinaria uma maior longevidade e funcionalidade dos implantes dentários

Clinical research in the implantology presents a great difficulty regarding the evaluation of the osseointegration and stability of the implants. Thus, resonance frequency analysis (RFA) has become one of the main tools used, since it offers, in a simple and non-invasive way, the possibility of monitoring the stabiblity during the desired period. Another measure also widely used in clinical practice is the insertion torque of the implants. However, this measureis limited to the transsurgical and provides only the primary stability of the implants, which makes it more suitable for evaluation the possibility of undergoing immediate loading. This study aims to evaluate, through a cross-sectional study, whether implant stability coefficient (ISQ) values are similar at different heights...

Implant survival and patient satisfaction of reduced diameter implants made from a titanium-zirconium alloy: A retrospective cohort study with 550 implants in 311 patients.

The aim of the study was to evaluate implant survival of reduced-diameter implants compared to regular-diameter implants. A retrospective evaluation of 154 Straumann Bone Level Roxolid® implants (diameter 3.3 mm) with SLActive®-surface in 107 patients, which were inserted between 2009 and 2010 in private practice, was performed. The mean observation period was 22.4 ± 8.2 months. 396 Straumann SLActive® implants (4.1 mm and 4.8 mm) in 204 patients, with an observation period of 28.4 ± 10.1 months served as control group. Implant survival rate, resonance frequency analysis and patient satisfaction were evaluated. The implant survival rate was 97.4% in the test vs. 98.5% in the control group. Resonance frequency analysis showed statistically significant lower values for the reduced-diameter implants. Patient satisfaction showed no significant difference between the test and the control group. Reduced-diameter implants displayed high survival rates during the period investigated and represent a convincing treatment alternative. Long-term follow-up investigations confirmed the high implant survival rates of 96.8% (after 69.7 ± 12.3 months) in the test group and 98.5% (after 76.0 ± 13.6 months) in the control group.

Polygonal Area of Prosthesis Support with Straight and Tilted Dental Implants in Edentulous Maxillae.

PURPOSE: The aim of this in vitro study was to assess the increase in the polygonal area of implant-retained prosthesis supports in edentulous maxillae with the use of tilted distal implants compared with the use of straight distal implants, using a variety of implant lengths. MATERIALS AND METHODS: A total of 25 DICOM datasets of atrophic edentulous maxillae were provided. Bone augmentations in the molar region had to be avoided. Two straight reference implants were virtually inserted in the anterior region. Two additional implants were placed far distally on both sides (4 groups: [1] straight, 12-mm length; [2] straight, 10 mm; [3] straight, 8 mm; [4] tilted, 12-16 mm). The resulting implant-supported polygon was measured for each of the 4 groups using three-dimensional planning software. RESULTS: The mean sagittal depth of the supported polygon in Group 1 was 9.9 mm (standard deviation [SD] 4.4) on the right and 10.2 mm (SD 4.4) on the left, and it was 33.7 mm (SD 5.8) in width. For Group 2, the mean sagittal depth was 11.5 mm (SD 5.0) on the right and 11.9 mm (SD 4.7) on the left, and the width was 35.2 mm (SD 5.6). The measurements for Group 3 were 13.8 mm (SD 4.9) deep on the right, 13.8 mm (SD 5.1) deep on the left, and 37.0 mm (SD 5.4) in width. For Group 4, the depth was 15.8 mm (SD 4.9) on the right and 16.4 mm (SD 5.8) on the left, and the width was 39.0 mm (SD 5.1). CONCLUSION: The area of implant-retained prosthesis support can be enlarged by the use of tilted implants (12 to 16 mm in length, 42 to 45 degrees) compared to the use of straight 8-mm implants (resulting increase: about 15%).

Predictability of short implants (< 10 mm) as a treatment option for the rehabilitation of atrophic maxillae. A systematic review

BACKGROUND: Short implants (< 10 mm) are one of the treatment options available in cases of limited vertical bone. Although such implants are now widely used, there is controversy regarding their clinical reliability. The purpose of this paper is to evaluate the predictability of short implants as an alternative to technically more complex treatments in patients with atrophic maxillae, based on a systematic review of the literature and the analysis of the implant survival rates, changes in periimplant bone level, and associated complications. It is postulated that short implants offer clinical results similar to those of longer implants. MATERIAL AND METHODS: A Medline-PubMed search was made covering the period between January 2004 and December 2014 (both included). Studies in English published in indexed journals, involving at least 20 implants and with a follow-up period of at least 12 months were considered. A manual search in four high impact journals was also conducted. RESULTS: A total of 37 studies meeting the inclusion criteria were included in this review. 9792 implants placed in over 5000 patients were analyzed. CONCLUSIONS: Based on the results of this review, short implants are seen to offer clinical results in terms of survival, bone loss and complications similar to those of longer implants

Reporting numeric values of complete crowns. Part 2: Retention and resistance theories.

STATEMENT OF PROBLEM: Determining the retention and resistance of a tooth preparation for a complete crown has only existed in theory, and these theories have never been measured on tooth preparations performed in vivo. PURPOSE: The purpose of this study was to measure the theoretical retention and resistance of clinically produced complete crown preparations by using an objective measuring method. MATERIAL AND METHODS: Stone dies from 236 complete crown preparations were collected from dental laboratories. The dies were scanned and analyzed with the coordinate geometry method. Cross-sectional images were captured, and the surface area was measured with a cone frustum and right truncated pyramid formula. Two different theories of resistance form, the "on" or "off" theory (limiting taper) and the linear model (resistance length), were calculated for premolar and molar preparations. RESULTS: The mean surface areas ranged from 33.97 mm(2) to 105.44 mm(2) for the cone frustum formula and 41.75 mm(2) to 117.50 mm(2) for the right truncated pyramid formula. The facial side of maxillary premolars exhibited the highest percentage of resistance form with the limiting taper, at 58%, and the mesial side of the mandibular molars exhibited the lowest percentage of resistance form, at 6%. CONCLUSIONS: The objective method used in this study provides a way for retention and resistance theories to be tested and for further clinical implications to be investigated.

Osteoporosis and bisphosphonate-related osteonecrosis in a dental school implant patient population.

PURPOSE: Studies have demonstrated an inconsistent association between implant failure and bone mineral density. The prevalence of osteoporosis in US adults has been reported to range from 5% to 10% in women and from 2% to 4% in men. The prevalence of bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) has been reported to range from 0% to 4.3% of patients taking oral BPs. The purpose of this study was to calculate the risk of dental implant loss and the incidence of BRONJ in patients with osteoporosis at the University of Kentucky College of Dentistry (UKCD). MATERIALS AND METHODS: This study analyzed data collected from patients who had implants placed between 2000 and 2004 at UKCD. Data were gathered from patient interviews regarding implant survival and patient-satisfaction parameters, and interviews were conducted either chairside at a scheduled maintenance appointment or by telephone interview. RESULTS: Among 203 patients who received 515 implants, the prevalence of osteoporosis was 23.3% for women and 1.2% for men. None of the 20 patients who reported a history of oral BP use exhibited BRONJ, and there were no implant failures in patients with a history of osteoporosis. CONCLUSIONS: In this study, osteoporosis conferred no risk of implant failure, and oral BP therapy was not associated with BRONJ.

Factors influencing fixed retention practices in German-speaking Switzerland: A survey.

AIM: Several surveys evaluate different retention approaches among orthodontists, but none exist for general dentists. The primary aim of this survey was to record the preferred fixed retainer designs and retention protocols amongst general dentists and orthodontists in Switzerland. A secondary aim was to investigate whether retention patterns were associated with parameters such as gender, university of graduation, time in practice, and specialist status. METHODS: An anonymized questionnaire was distributed to general dentists (n = 401) and orthodontists (n = 398) practicing in the German-speaking part of Switzerland. A total of 768 questionnaires could be delivered, 562 (73.2 %) were returned and evaluated. Descriptive statistics were performed and responses to questions of interest were converted to binary outcomes and analyzed using multiple logistic regression. Any associations between the answers and gender, university of graduation (Swiss or foreign), years in practice, and specialist status (orthodontist/general dentist) were assessed. RESULTS: Almost all responding orthodontists (98.0 %) and nearly a third of general dentists (29.6 %) reported bonding fixed retainers regularly. The answers were not associated with the practitioner's gender. The university of graduation and number of years in practice had a moderate impact on the responses. The answers were mostly influenced by specialist status. CONCLUSION: Graduation school, years in practice, and specialist status influence retention protocol, and evidence-based guidelines for fixed retention should be issued to minimize these effects. Based on the observation that bonding and maintenance of retainers are also performed by general dentists, these guidelines should be taught in dental school and not during post-graduate training.

The clinical performance of porcelain-fused-to-metal precious alloy single crowns: chipping, recurrent caries, periodontitis, and loss of retention.

PURPOSE: This retrospective study investigated the frequency and time history of chipping and facing failures, recurrent caries (RC), periodontitis (PE), and loss of retention (LR) of porcelain-fused-to-metal (PFM) single crowns. MATERIALS AND METHODS: A total of 997 PFM single crowns had been inserted according to a standardized treatment protocol from January 1984 to May 2009. The frequency and time history of chipping and facing failures were evaluated, as were possible risk factors from historical clinical data. Risk factors were bruxism, the type of antagonist, and the location of crowns (mandible, maxilla, anterior, posterior). The survival times of crowns were estimated using Kaplan-Meier (KM) analysis. RESULTS: The median follow-up time calculated with the inverse KM method was 4.33 years. Anterior and posterior PFM crowns showed 5-year survival rates (time to crown replacement) of 96.4% and 97.5% and 10-year survival rates of 92.3% and 95.9%, respectively. Chipping was found in 17 (1.7%) of the 997 PFM crowns. According to the KM method, the 5- and 10-year free-of-event-rates for chipping of anterior crowns were both 98.9%, and the rates for posterior crowns were 98.2% for 5 years and 97.3% for 10 years. Thirteen patients showed RC (1.3%) and 144 (14.4%) PE. The 5-year free-of-event-rate for RC was 98.7% and the 10-year free-of-event rate was 97.2%. For PE, the 5-year free-of-event-rate was 85.8% and the 10-year free-of-event rate was 72.2%. The 5- and 10-year free of- event-rates for LR were 92.2% each for anterior teeth and 97.1% each for posterior teeth. CONCLUSIONS: Patients with PFM crowns may expect long-term survival for their restoration. Clinical complications are rare. Chipping of the veneer or loss of retention may occur during the first few years. While chipping of the veneer may occur during the first few years, the frequency of caries or periodontitis increases with the length of oral service and with age.

Improvements in implant dentistry over the last decade: comparison of survival and complication rates in older and newer publications.

PURPOSE: The objective of this systematic review was to assess and compare the survival and complication rates of implant-supported prostheses reported in studies published in the year 2000 and before, to those reported in studies published after the year 2000. MATERIALS AND METHODS: Three electronic searches complemented by manual searching were conducted to identify 139 prospective and retrospective studies on implant-supported prostheses. The included studies were divided in two groups: a group of 31 older studies published in the year 2000 or before, and a group of 108 newer studies published after the year 2000. Survival and complication rates were calculated using Poisson regression models, and multivariable robust Poisson regression was used to formally compare the outcomes of older and newer studies. RESULTS: The 5-year survival rate of implant-supported prostheses was significantly increased in newer studies compared with older studies. The overall survival rate increased from 93.5% to 97.1%. The survival rate for cemented prostheses increased from 95.2% to 97.9%; for screw-retained reconstruction, from 77.6% to 96.8%; for implant-supported single crowns, from 92.6% to 97.2%; and for implant-supported fixed dental prostheses (FDPs), from 93.5% to 96.4%. The incidence of esthetic complications decreased in more recent studies compared with older ones, but the incidence of biologic complications was similar. The results for technical complications were inconsistent. There was a significant reduction in abutment or screw loosening by implant-supported FDPs. On the other hand, the total number of technical complications and the incidence of fracture of the veneering material was significantly increased in the newer studies. To explain the increased rate of complications, minor complications are probably reported in more detail in the newer publications. CONCLUSIONS: The results of the present systematic review demonstrated a positive learning curve in implant dentistry, represented in higher survival rates and lower complication rates reported in more recent clinical studies. The incidence of esthetic, biologic, and technical complications, however, is still high. Hence, it is important to identify these complications and their etiology to make implant treatment even more predictable in the future.

Effect of location on primary stability and healing of dental implants.

PURPOSE: To study implant primary stability and bone healing using resonance frequency analysis in different anatomical locations 4 months after placement. MATERIAL AND METHODS: Fifty-six partially edentulous patients restored by dental implants were included. Overall, 214 implants were placed without bone or soft tissue augmentation. All implants were placed with the same drilling protocol and implant insertion torque (35-40 N · cm). RESULTS: The mean implant stability quotient (ISQ) value at baseline for all the locations was 75.4 mm (95% confidence interval, 74.20-76.59 mm). Higher ISQ values were found in the mandible. A significant difference between ISQ values of each location (P < 0.001) was identified. The mean values obtained showed an increase (3.4%) in all the locations, being greater in the posterior lower and upper maxillae (3.8%), whereas for the anterior maxilla, it was the least (1.5%) 4 months after healing. This increase was statistically significant in the posterior upper and lower maxillae (P < 0.001). CONCLUSION: Higher implant stability was found in mandible compared with maxilla in both periods, immediately after insertion and 4 months later. Therefore, according to ISQ values, restoring implants immediately after insertion or after a healing period of 4 months represents safe time points.

Evaluation of possible prognostic factors for the success, survival, and failure of dental implants.

PURPOSE: To analyze the prognostic factors that are associated with the success, survival, and failure rates of dental implants. MATERIAL AND METHODS: Data including implant sizes, insertion time, implant location, and prosthetic treatment of 1656 implants have been collected, and the association of these factors with success, survival, and failure of implants was analyzed. RESULTS: The success rate was lower for short and maxillary implants. The failure rate of maxillary implants exceeded that of mandibular implants, and the failure rate of implants that were placed in the maxillary anterior region was significantly higher than other regions. The failure rates of implants that were placed 5 years ago or more were higher than those that were placed later. CONCLUSIONS: Anterior maxilla is more critical for implant loss than other sites. Implants in the anterior mandible show better success compared with other locations, and longer implants show better success rates. The learning curve of the clinician influences survival and success rates of dental implants.

One-year survival rate outcomes of innovative dental implants: a prospective clinical study.

PURPOSE: The aim of this research was to evaluate an innovative implant design for different placement and loading protocols. The unique implant is a combination of tapered and cylindrical shape, which is aimed to enhance initial stability and long-term osseointegration. MATERIALS AND METHODS: Four hundred and sixty implants were placed in 141 patients under different placement and loading protocols in similarity to those encountered in a dental office. Implants were followed and evaluated for 1 year to assert the survival rate of the newly introduced implant. RESULTS: The results showed a total of 97.4% survival rate, ranging from 92% to 98.6% depending on the different protocols. There was no statistical difference between the different protocol groups. CONCLUSION: The new implant design showed good results for 1 year of follow-up, comparable with the literature, and could be a good choice for every implant-based procedure.

Brånemark system implant lengths in the pterygomaxillary region: a retrospective comparison.

PURPOSE: Implants that engage the cortical bone of the pterygomaxillary region help restore dentition to the posterior maxilla. However, proper implant length is required. The purpose of this study was to determine if there is a statistically significant difference in the survival rates between different sized implants placed in the pterygomaxillary region. MATERIALS AND METHODS: All Brånemark System 4.0-mm-diameter implants delivered into the pterygomaxillary region in a single private practice were separated into 7- to 13-mm and 15- to 18-mm groups by retrospective patient chart review. Cumulative survival rates (CSR) were calculated. RESULTS: Of all implants delivered, 930 of the 992 osseointegrated for a CSR of 93.75%. Fifty-nine of the 67 implants in the 7- to 13-mm grouping and 871 of the 925 implants in the 15- to 18-mm grouping osseointegrated for CSRs of 88.06% and 94.16%, respectively. The results were statistically significant (P < 0.05). CONCLUSIONS: The results suggest that increased implant length in the pterygomaxillary region may result in higher osseointegration rates. The implant apex better engages the cortical bone between the medial and lateral pterygoid plates and therefore increases primary and secondary stability.

Implant-retained dental rehabilitation in head and neck cancer patients: an assessment of success and failure.

BACKGROUND: This study aimed to evaluate the rate of osseointegration (ROI) and overall success rate (OSR) of implants placed in native and grafted jaws with or without radiotherapy at a 5-year follow-up in Indian head and neck cancer patients. MATERIAL AND METHODS: Thirty head and neck cancer patients from various socioeconomic strata were accrued. Eighty-five implants were inserted in 17 native and 13 grafted jaws. Nineteen patients received radiation therapy. A 5-year follow-up ROI and OSR of implants were reported. RESULTS: The 5-year ROI and OSR were 88% and 77%, respectively. ROI was 93% for grafted, 85% for native, 83% for irradiated, and 100% for nonirradiated jaws. OSR was 73% for grafted, 80% for native, 71% for irradiated, and 89% for nonirradiated jaws. Patients from higher socioeconomic strata had higher OSR (92%) as compared with those belonging to lower socioeconomic strata (65%). CONCLUSION: The failure rate observed in this study was 24% for implants placed in head and neck cancer patients at a 5-year follow-up.

The relationship between resonance frequency analysis (RFA) and lateral displacement of dental implants: an in vitro study.

This in vitro investigation was conducted to study the relationship between resonance frequency analysis (RFA) and lateral displacement measurements of dental implants. A total of 30 implant sites were prepared in nine fresh bovine bone specimens. The bone density around each preparation was determined by using cone beam computerized tomography (CBCT) and imaging software. Dental implants were then inserted during continuous registration of insertion torque. RFA measurements were performed in perpendicular and parallel to the long axis of the specimens. The bone blocks were embedded in plaster and fixated in a specially designed rig for displacement measurements. A lateral force of 25 N was applied via an abutment perpendicular and parallel to each implant and the displacement measured in µm. In addition, a flex constant (µm N(-1) ) was calculated for each measurement. There was a significant inverse correlation between RFA and lateral implant displacement (µm) measurements and between RFA measurements and the flex constant in both perpendicular and parallel directions in bone (P ≤ 0·001). Moreover, both RFA and displacement measurements correlated with bone density (P ≤ 0·001). It is concluded that RFA measurements reflect the micromobility of dental implants, which in turn is determined by the bone density at the implant site.

One-year results of a clinical and radiological prospective multicenter study on NEOSS® dental implants.

BACKGROUND: NEOSS® (Neoss Ltd., Harrogate, UK) dental implant system was introduced on the clinical arena in 2003. It is important that novel implant systems are systematically evaluated in a multicenter setting. PURPOSE: The aim of this study was to follow a large number of consecutively treated patients, with NEOSS dental implant system, both clinically and radiographically. The current report constitutes the 1-year data of a planned 5-year study. MATERIALS AND METHODS: The study included a total of 177 patients treated with 590 NEOSS implants at 13 clinics in Sweden. The material was composed of 72 males and 105 females treated for single, partial, and total edentulism. Clinical, radiographic, and subjective evaluations were performed. RESULTS: Out of 590 implants, 13 early failures have been reported, corresponding to a 1-year cumulative survival rate (CSR) of 97.8%. Evaluation of function and esthetics at the 1-year visit resulted in 100% success for function and 98% success for the esthetic outcome. The mean marginal bone loss was 0.6 mm (SD 1.1) after 1 year in clinical function. No adverse effects of the NEOSS dental implants were reported, and complications were few and similar to those reported for implant treatment in general. CONCLUSION: The CSR in the present study was 97.8%. No adverse effects of the NEOSS implants were reported, and complications during the study period were few and similar to those reported to for other well-documented implants system. Based on the present data, we conclude that NEOSS dental implant is a safe and predictable implant system. However, the high number of dropouts in the radiological evaluation must be considered when interpreting the data.