Osseoperception in Dental Implants: A Systematic Review.

PURPOSE: Replacement of lost teeth has significant functional and psychosocial effects. The capability of osseointegrated dental implants to transmit a certain amount of sensibility is still unclear. The phenomenon of developing a certain amount of tactile sensibility through osseointegrated dental implants is called osseoperception. The aim of this article is to evaluate the available literature to find osseoperception associated with dental implants. MATERIALS AND METHODS: To identify suitable literature, an electronic search was performed using Medline and PubMed database. Articles published in English and articles whose abstract is available in English were included. The articles included in the review were based on osseoperception, tactile sensation, and neurophysiological mechanoreceptors in relation to dental implants. Articles on peri-implantitis and infection-related sensitivity were not included. Review articles without the original data were excluded, although references to potentially pertinent articles were noted for further follow-up. The phenomenon of osseoperception remains a matter of debate, so the search strategy mainly focused on articles on osseoperception and tactile sensibility of dental implants. This review presents the histological, neurophysiological, and psychophysical evidence of osseoperception and also the role of mechanoreceptors in osseoperception. RESULTS: The literature on osseoperception in dental implants is very scarce. The initial literature search resulted in 90 articles, of which 81 articles that fulfilled the inclusion criteria were included in this systematic review. CONCLUSION: Patients restored with implant-supported prostheses reported improved tactile and motor function when compared with patients wearing complete dentures.

Extraoral implants in the rehabilitation of craniofacial defects: implant and prosthesis survival rates and peri-implant soft tissue evaluation.

PURPOSE: Few reports have evaluated cumulative survival rates of extraoral rehabilitation and peri-implant soft tissue reaction at long-term follow-up. The objective of this study was to evaluate implant and prosthesis survival rates and the soft tissue reactions around the extraoral implants used to support craniofacial prostheses. MATERIALS AND METHODS: A retrospective study was performed of patients who received implants for craniofacial rehabilitation from 2003 to 2010. Two outcome variables were considered: implant and prosthetic success. The following predictor variables were recorded: gender, age, implant placement location, number and size of implants, irradiation status in the treated field, date of prosthesis delivery, soft tissue response, and date of last follow-up. A statistical model was used to estimate survival rates and associated confidence intervals. We randomly selected 1 implant per patient for analysis. Data were analyzed using the Kaplan-Meier method and log-rank test to compare survival curves. RESULTS: A total of 150 titanium implants were placed in 56 patients. The 2-year overall implant survival rates were 94.1% for auricular implants, 90.9% for nasal implants, 100% for orbital implants, and 100% for complex midfacial implants (P = .585). The implant survival rates were 100% for implants placed in irradiated patients and 94.4% for those placed in nonirradiated patients (P = .324). The 2-year overall prosthesis survival rates were 100% for auricular implants, 90.0% for nasal implants, 92.3% for orbital implants, and 100% for complex midfacial implants (P = .363). The evaluation of the peri-implant soft tissue response showed that 15 patients (26.7%) had a grade 0 soft tissue reaction, 30 (53.5%) had grade 1, 6 (10.7%) had grade 2, and 5 (8.9%) had grade 3. CONCLUSIONS: From this study, it was concluded that craniofacial rehabilitation with extraoral implants is a safe, reliable, and predictable method to restore the patient's normal appearance.

The establishment of a protocol for the total rehabilitation of atrophic maxillae employing four zygomatic fixtures in an immediate loading system--a 30-month clinical and radiographic follow-up.

BACKGROUND: The existing approaches to the treatment of the atrophic maxilla are difficult and involve an element of risk. PURPOSE: The aim of the present study was to establish a new surgical/prosthetic protocol for the treatment of extremely atrophic maxillae using four zygomatic implants (ZIs) in an immediate loading system. MATERIALS AND METHODS: Twelve patients were treated with the surgical placement of 48 ZIs, and the totally edentulous maxillae were rehabilitated with protocol-type maxillary prostheses rigidly fixed to the ZIs in an immediate loading system. Follow-up was conducted at 6 months and again at 30 months. RESULTS: Of the 48 ZIs inserted, one implant failed to achieve osseointegration. The prosthetic components fitted well and no sinus pathology was detected in any of the patients. CONCLUSION: The surgical/prosthetic protocol showed that it was possible to insert four ZIs in an immediate loading system and achieve stability for up to 30 months.

Osseointegrated wrist-joint prostheses: a 15-year follow-up with focus on bony fixation.

Five patients with rheumatoid arthritis or osteoarthrosis of the wrist joint were followed up for 15 (14-17) years after wrist-joint arthroplasty with semiconstrained artificial joint mechanisms that had been anchored to bone using the osseointegration principle. They were fixed by one titanium screw introduced into the radius, and two or more titanium screws introduced distally into the metacarpal bones. In four cases a screw was also introduced into the ulna thereby constituting one component in a distal radio-ulnar (DRU) joint mechanism. The titanium screw introduced into the radius and the distal metacarpal screws osseointegrated in all cases. In three cases the mechanism of the wrist joint or parts of it were replaced with new components that could be attached to the screws that were already osseointegrated. We conclude that wrist joint prostheses can be anchored to the surrounding bone using osseointegration and that they remain fixed for at least 15 years. The principle allows replacement of the joint mechanism, if needed, with maintenance of the osseointegrated anchoring elements.

Zygomatic bone: anatomic bases for osseointegrated implant anchorage.

PURPOSE: The aim of the present study was to evaluate zygomatic bone thickness considering a possible relationship between this parameter and cephalic index (CI) for better use of CI in the implant placement technique. MATERIALS AND METHODS: CI was calculated for 60 dry Brazilian skulls. The zygomatic bones of the skulls were divided into 13 standardized sections for measurement. Bilateral measurements of zygomatic bone thickness were made on dry skulls. RESULTS: Sections 5, 6, 8, and 9 were appropriate for implant anchorage in terms of location. The mean thicknesses of these sections were 6.05 mm for section 5, 3.15 mm for section 6, 6.13 mm for section 8, and 4.75 mm for section 9. In only 1 section, section 8, did mean thickness on 1 side of of the skull differ significantly from mean thickness on the other side (P <.001). DISCUSSION: For the relationship between quadrant thickness and CI, sections 6 and 8 varied independently of CI. Section 5 associated with brachycephaly, and section 9 associated with subbrachycephaly, presented variations in the corresponding thickness. CONCLUSION: Based on the results, implants should be placed in sections 5 and 8, since they presented the greatest thickness, except in brachycephalic subjects, where thickness was greatest in section 5, and in subbrachycephalic subjects, where thickness was greatest in section 9. CI did not prove to be an appropriate parameter for evaluating zygomatic bone thickness for this sampling. (More than 50 references.)

Histological evaluation of bone formation adjacent to dental implants with a novel apical chamber design: preliminary data in the rabbit model.

BACKGROUND: Wound healing events after implant placement will vary according to the extent of the necrotic zone. PURPOSE: The goal of the present study was to evaluate bone healing around titanium implants with a novel apical chamber design. MATERIALS AND METHODS: Titanium implants grade 4 were turned with different apex design. Control implants had a self tapping design with centric cutting grooves. Test implants exhibited eccentric cutting grooves interconnected by a hollow chamber. A total of 60 implants were installed in the femur/tibia of 10 rabbits for histological analysis. RESULTS: After 1 week, immature bone formation started at the cortical level of the test implants associated to scalloped contours indicative of bone resorption. Control implants failed to show new bone formation, and the space within the threads was filled mainly by red blood cells and surgical debris. Bone contact values showed no difference after 1 week, and significant higher values for test implants showed likewise after 4 weeks compared with control implants in the tibia. CONCLUSION: This experimental study verifies the beneficial effect of bone formation in the chamber at the apical part of the fixture coupled to a faster bone healing to implants placed in dense bone.

Key biomechanical characteristics of complete-arch fixed mandibular prostheses supported by three implants developed at P-I Brånemark Institute, Bauru.

PURPOSE: To determine the range of vertical cantilever (VC), real cantilever (RC), and height of the imaginary triangle (h) formed by the bases of the three implant cylinders in full-arch mandibular prostheses supported by three implants. MATERIALS AND METHODS: The sample comprised 203 patients (147 women, 56 men; mean age, 58 years, range, 37 to 79 years) with full-arch mandibular rehabilitations. Their prostheses were measured in relation to implant placement to characterize numerical values for VC, force arm of the lever system (represented by the distal cantilever or RC), and resistance arm of the system (represented by the height of the imaginary triangle formed by the bases of the three implants). Data were tabulated and means and standard deviations calculated for all measurements. The range of each of the three measurements was then divided into quintiles for characterizing data distribution. RESULTS: The mean (standard deviation) values found were as follows: VC1 = 17.11 (3.39) mm; VC2 = 17.46 (2.89) mm; VC3 = 16.68 (3.16) mm; RC1 = 14.67 (3.90) mm; RC3 = 15.02 (4.15) mm; h = 8.27 (2.96) mm. CONCLUSION: VC ranged from 7.37 to 26.44 mm, RC ranged from 4.00 to 26.93 mm, and the height of the imaginary triangle formed by the bases of the three implant cylinders ranged from 0.37 to 15.33 mm.

Prospective follow-up study of 95 patients with edentulous mandibles treated according to the Brånemark Novum concept.

BACKGROUND: The long-term predictability reported with the traditional two-staged Brånemark method has led to developments aimed at simplifying the technique and reducing healing time. Results from a pilot study using the Brånemark Novum concept are promising, and it has been shown possible to fabricate and deliver an implant-supported fixed prosthesis to the patient on the day of surgery. PURPOSE: The objective of this study is to report clinical and radiographic outcomes in a group of patients treated according to the Brånemark Novum concept. MATERIALS AND METHODS: Ninety-five patients with edentulous mandibles were consecutively included in the study. Three specially designed fixtures were placed in each patient (285 fixtures in total) using drilling templates. The fixtures were immediately splinted with a prefabricated substructure, and fixed prostheses were delivered the same day in 67% of the patients. For the rest, prosthesis delivery ranged from 1 to 40 days (mean 5.6 d). Clinical and radiographic examinations were performed after 3 months, 6 months, 1 year, and then annually. The follow-up time was 1 to 5 years (mean 2.5 yr). RESULTS: The cumulative prosthesis survival rate was 99%. Eighteen fixtures (6.3%) failed in 13 patients. Kaplan-Meier survival estimates demonstrated a probability implant survival at 1 year of 95.0% (94 patients), at 3 years of 93.3% (47 patients), and at 5 years of 93.3% (9 patients). The mean bone loss was 0.73 mm between the examinations at 3 months and 1 year, 0.16 mm during the second year, and 0.13 mm annually during years 3 to 5. CONCLUSIONS: Comparable results, related to continuous prosthesis stability, were shown for the Novum approach compared with the traditional two-staged procedure. Survival of individual fixtures is lower when immediate loading is applied.

Zygoma fixture in the management of advanced atrophy of the maxilla: technique and long-term results.

Despite refinements in surgical technique, including bone grafting and sophisticated prosthetic reconstructions, there are limitations to what can be achieved with bone-anchored fixed prostheses in patients with advanced atrophy of the maxillae. A new approach was suggested by a long-term study on onlay bone grafting and simultaneous placement of a fixture based on a new design: the zygoma fixture, and the aim of this study was to assess its potential. Twenty-eight consecutive patients with severely resorbed edentulous maxillae were included, 13 of whom had previously had multiple fixture surgery in the jawbone that had failed. A total of 52 zygoma fixtures and 106 conventional fixtures were installed. Bone grafting was deemed necessary in 17 patients. All patients have been followed for at least five years, and nine for up to 10 years. All patients were followed up with clinical and radiographic examinations, and in some cases rhinoscopy and sinoscopy as well. Three zygoma fixtures failed; two at the time of connection of the abutment and the third after six years. Of the conventional fixtures placed at the time of the zygoma fixture, 29 (27%) were lost. The overall prosthetic rehabilitation rate was 96% after at least five years of function. There were no signs of inflammatory reaction in the surrounding antral mucosa. Four patients with recurrent sinusitis recovered after inferior meatal antrostomy. To conclude, the zygoma fixture seems to be a valuable addition to our repertoire in the management of the compromised maxilla.

Assessment of rehabilitation in edentulous patients treated with an immediately loaded complete fixed mandibular prosthesis supported by three implants.

PURPOSE: Conventionally, in patients with completely edentulous mandibles, fixed prostheses have been supported by four or more implants. However, an alternative protocol employing three implants and immediate loading has been developed. The objective of the present study was to assess the rehabilitation of edentulous patients treated with a complete fixed mandibular prosthesis with immediate loading and supported by three implants. MATERIALS AND METHODS: In this observational study, a total of 99 implants placed in 33 patients was evaluated after 18 months in use. Panoramic radiographs were digitized to measure bone loss at the mesial and distal surfaces of each implant. RESULTS: Mean peri-implant bone loss was 0.66 ± 0.51 mm for the left implant, 0.92 ± 0.61 mm for the central implant, and 0.82 ± 0.53 mm for the right implant. The bone loss observed around the distal implants was similar to that seen around the central implant, and there were no statistically significant differences in peri-implant bone loss between the three implant locations. There was no significant correlation between implant length and bone loss. The results were compatible with the peri-implant bone loss that has been described for prostheses of the same type supported by larger numbers of implants. CONCLUSIONS: The use of a complete fixed mandibular prosthesis with immediate loading supported by three implants proved to be an adequate option for the rehabilitation of edentulous patients. The protocol allowed simplification of treatment while maintaining similar bone loss to that reported for the same type of treatment supported by a larger number of implants.

Clinical evaluation of the zygoma implant: 3-year follow-up at 16 clinics.

PURPOSE: The purpose of this clinical investigation was to evaluate the treatment outcome with zygoma implants with regard to implant survival, patient satisfaction, and function of prosthesis replacement after 3 years. PATIENTS AND METHODS: The treatment outcome of 76 patients treated with 145 zygoma fixtures at 16 centers was evaluated with regard to implant survival. Status of peri-implant mucosa and amount of plaque were registered annually. Patients' and dentists' evaluations of the functional and esthetic outcome of the treatment were assessed at delivery of prosthesis and thereafter at each follow-up visit. RESULTS: Sixty of 76 patients were followed for 3 years after prosthetic delivery. Five of 145 placed zygoma implants failed during the course of the study resulting in an overall implant survival rate of 96.3%. At the 3-year follow-up, 75% of the implants sites were registered with normal peri-implant mucosa and 68% with no visible plaque. The patients were fully satisfied with the esthetic and functional outcome of the treatment in 86% and 71%, respectively, at the 3-year follow-up visit. All reported data from dentists scored from acceptable to excellent. CONCLUSION: The multicenter study showed a high predictability of the zygoma implant-supported rehabilitation.

Edentulousness and oral rehabilitation: experiences from the patients' perspective.

The psychological effects of tooth loss in the permanent dentition are relatively unknown. Complete edentulousness is a serious life event in terms of readjustment. The aim of the study was to describe the process patients with deteriorating dental status had gone through before treatment with a fixed prosthesis (Brånemark System, Novum), and to describe what living with a fixed prosthesis means to the patients themselves. In-depth interviews were carried out with 18 patients, and the interviews were transcribed verbatim and analysed in open, axial and selective coding processes according to Grounded Theory. In the analysis, four categories were developed and labelled: 'alterations in self-image', 'becoming a deviating person', 'becoming an uncertain person' and 'becoming the person I once was'. 'Alterations in self-image' was identified as the core category and was related to the other three categories. The core category describes the changes in self-image starting with the subjects' increasingly worsened dental status, followed by a period of them having to live and cope with a denture and, finally, their living with a fixed prosthesis. The motive power for the decision to undergo treatment with a fixed prosthesis seems to be a desire to restore dental status and also to recapture attractiveness, self-esteem and a positive self-image.

A clinical evaluation of the Zygoma fixture: one year of follow-up at 16 clinics.

PURPOSE: To evaluate treatment outcome with Zygoma fixtures (Nobel Biocare, Göteborg, Sweden) with regard to fixture survival, patient satisfaction, and function of prosthesis replacement. MATERIALS AND METHODS: The treatment outcome of 76 patients treated with 145 Zygoma fixtures at 16 centers was evaluated. Patient's and dentist's evaluations of the functional and aesthetic outcome of the treatment were assessed at delivery of prosthesis and at the 1-year follow-up visit. At the 1-year follow-up visit, the status of the peri-implant mucosa around the abutments and the amount of plaque were registered. RESULTS: Sixty-six of the 76 patients, with 124 Zygoma fixtures supporting the prosthetic restorations, were evaluated at the 1-year follow-up. The overall survival rate for the Zygoma fixtures was 97.9% after 1-year of follow-up. Eighty percent of the patients were fully satisfied with both aesthetic and functional outcome at the time of prosthetic insertion and at the 1-year follow-up. All reported data from the dentists, with the exception of one restoration with several abutment screw loosenings, scored from acceptable to excellent for the aesthetic and functional outcome of the treatment. The status of peri-implant mucosa was recorded as normal in approximately 60% of the sites. Plaque, when present, was more often detected on the palatal surfaces compared with the buccal surfaces. CONCLUSION: This 1-year follow-up of Zygoma fixtures has shown good results with an acceptable number of minor complications and a majority of satisfied patients.

Avaliação do nível de satisfação e da qualidade de vida relacionada à saúde oral de pacientes edêntulos reabilitados com próteses fixas sobre três implantes em mandíbula / Assessment of patient satisfaction and oral health-related quality of life of edentulous patients with three-implant-supported mandibular fixed prosthesis

A reabilitação de pacientes desdentados totais inferiores sempre foi um dos grandes desafios da Odontologia. A descoberta da Osseointegração modificou o panorama das possibilidades terapêuticas de reabilitação oral. Além da questão técnica cirúrgica e protética, a avaliação da satisfação e da qualidade de vida é fundamental quando se visa o sucesso na terapia com implantes dentários. Objetivos: verificar o nível de satisfação e qualidade de vida relacionada à saúde oral de indivíduos edêntulos totais reabilitados com prótese fixa sobre três implantes sob carga imediata. Metodologia: 67 indivíduos participaram do estudo, sendo 24 do gênero masculino e 43 do gênero feminino. Os pacientes submeteram-se a colocação de três implantes e confecção de uma prótese fixa de carga imediata na arcada inferior. O nível de satisfação foi avaliado através da escala analógica visual (EAV) e a qualidade de vida relacionada à saúde oral foi verificada através do questionário Ohip-Edent, versão validada para o português brasileiro 18 meses após concluída a reabilitação protética. Resultados: a média de satisfação na escala EAV relatada foi de 9,15 (± 1,8). A média de escore Ohip-Edent foi de 2,60 (± 2,69). Conclusão: a avaliação do nível de satisfação e qualidade de vida relacionada à saúde oral demonstrou que o protocolo adotado no presente estudo proporcionou aos pacientes desdentados totais uma alternativa de tratamento capaz de reabilitar as funções orais, sociais e psicológicas, reduzindo custos e tempo de tratamento

Rehabilitation of the totally edentulous mandible has always been one of the greatest challenges of Dentistry. The advent of osseointegration has opened up a new range of therapeutic possibilities for oral rehabilitation. In addition to surgical and prosthetic management, assessment of patient satisfaction and quality of life is essential for achieving success in dental implant therapy. Objective: To determine patient satisfaction and oral health-related quality of life of edentulous patients treated with three-implant-supported mandibular fixed prosthesis with immediate loading. Methods: The sample consisted of 67 individuals, 24 men and 43 women. After placement of three implants, each patient received an immediately loaded implant-supported fixed prosthesis in the mandible. Patient satisfaction was assessed using a visual analog scale (VAS) and oral health-related quality of life by the Ohip-Edent questionnaire, validated for the Brazilian population, 18 months after completion of prosthetic rehabilitation. Results: Mean patient VAS satisfaction score was 9.15 (±1.8). Mean Ohip-Edent score was 2.60 (± 2.69). Conclusion: The assessment results of patient satisfaction and oral health-related quality of life showed that the protocol adopted in the present study provided totally edentulous patients with a treatment option capable of rehabilitating oral, social and psychological functions, associated with reduced costs and shorter treatment time