Relationship Between Implant Stability Measurements Obtained by Two Different Devices: A Systematic Review.

BACKGROUND: The aim of this systematic review is to evaluate the relationship between two methods used to assess implant stability, investigating whether both provide similar implant stability assessments for the same clinical case. METHODS: A literature search was conducted on MEDLINE-PubMed and Scopus databases, without limitation of the publication period, up to November 2015. The following key words were used, with associations among them: "dental implant," "dental implants," "Osstell," "resonance frequency analysis," "implant stability quotient," "ISQ," "Periotest," "Periotest value," and "PTV." Inclusion criteria were English language, prospective, retrospective, and randomized controlled clinical trials that evaluated implant stability through use of resonance frequency analysis (RFA) and damping capacity analysis (DCA). The study should assess implant stability of only a specific region for all patients or discriminate results evaluated for each region if the analysis had been made in various regions; RFA and DCA should have been applied in the same implants and periods. Studies have been carefully selected, and data of interest were tabulated. RESULTS: Six studies met the inclusion criteria. Although there was significant numerical correlation between values obtained by both methods, data showed that less than half (46%) of cases coincided in relation to implant stability classification. CONCLUSIONS: It can be considered that there is not always a consensus and standardization in the classification of implant stability related to the values obtained by RFA and DCA devices, which could create disagreements and miscommunication among dentistry professionals.

Epidemiological Data and Survival Rate of Removable Partial Dentures.

INTRODUCTION: The use of removable partial denture (RPD) is considered as low-cost and common treatment option to rehabilitate edentulous areas. AIM: This study aimed to investigate the epidemiological data of patients rehabilitated with removable partial denture (RPD) in order to assess treatment survival rate and failures. MATERIALS AND METHODS: Epidemiological data and medical records of patients treated with RPD between 2007 and 2012 at the RPD discipline of a Brazilian University (Aracatuba Dental School- UNESP) were evaluated as well as dental records of patients who underwent RPD treatments (fabrication or repairs) between 2000 and 2010. Factors such as gender, age, presence of systemic disease, main complaint, edentulous arch, period and cause of denture replacement and the prosthesis characteristics were recorded. The chi-square test was used to assess the differences between the variables and the Kaplan Meyer to assess the survival of the RPDs evaluated. RESULTS: A total of 324 maxillary RPD and 432 mandibular RPD were fabricated. Most of the patients were women aging 41 to 60-year-old. The number of mandibular RPD Kennedy class I (26%) was statistically higher for the maxillary arch (p<.05). There was no association between main complaint to gender or the presence of systemic disease. The lingual plate was the most common major connector used in the mandible (32%). The main reason for altering the design of replaced RPDs were changes during treatment plan. CONCLUSION: The number of patients who require RPD is large; most of RPDs are Kennedy Class I. A good treatment plan is very important for achieving a positive treatment outcome, and it is strictly related to the survival rate.

Stress Analysis of Axial and Tilted Implants in Full-arch Fixed Dentures Under Different Abutment Conditions.

The aim of this study was to evaluate the stress distribution on full-arch prostheses, considering axial implants and tilted implants with or without abutments. Two photoelastic models were made, being that in 1 model the implants were inserted perpendicular, whereas in the other model 2 implants were inserted perpendicular and 2 implants were inserted with tilting 30° to the distal area. The prosthetic situations were evaluated: A-axial implants and nonsegmented full-arch prosthesis; B-axial implants and segmented full-arch prosthesis; C-tilted distal implants and nonsegmented full-arch prosthesis; D-tilted distal implants and segmented full-arch prosthesis, and was applied an axial load of 100 N at 5 points. The results showed greater stress concentration for axial implants than tilted implants in anterior and posterior loading. There was no difference in stress distribution to the use of abutment in the tilted implants. Shorter cantilever with tilted implants improved the stress distribution; the use of abutment did not influence the stress distribution.

Análise da transferência de implantes pela técnica sem moldagem por meio de método fotográfico / Analysis of implant transfer technique without impression material by photographic method

Objetivo: Avaliar a precisão da técnica de transferência de implantes sem material de moldagem, comparando-a ao posicionamento dos implantes de um modelo padrão. Material e Método: modelo em resina acrilica com três implantes instalados na área dos dentes 35 e 36 foi reproduzido, obtendo-se três modelos cujas áreas dos implantes foram recortadas para permitir a transferência dos mesmo. No modelo padrão os transferentes foram unidos com resina duralay estendendo-se às porções oclusais dos dentes adjacentes aos implantes. Após a polimerização os transferentes foram desparafusados, conectados aos análogos e posicionados nos modelos reproduzidos, pelas extensões da resina nas superfícies oclusais dos dentes que limitam o espaço e vertido gesso tipo IV. O modelo padrão e os 3 modelos foram fotografados pelas superfícies vestibular e oclusal, com distância igual para todos os modelo. As alterações de posicionamento dos implantes, decorrentes de suas transferências, foram mensurada pelo programa Corei Draw 3, comparando-se as medidas do modelo padrão com as dos modelos obtidos. Resultados: Foram observados alterações das posições de todos os implantes transferidos sendo no sentido mesial, para todos os implantes (A, B e C) no sentido bucal para os implantes A e B e vestibular para o implante C. Conclusões: Todos os valores dos implantes transferidos forma menores do que 0,5 graus e a diferença entre os valores do modelo padrão e a média dos valores dos modelos transferidos pode ser suficiente para influenciar no assentamento passivo entre as estruturas.

Objective: Analyze the accuracy of implants transfer technique without impression materia comparing it to the implants positioning of a standard model. Material and Method: A standard modei with three dental implants inserted in the region 35 and 36 teeth was reproduced, getting three models (1. 2 and 3) whose areas of implants were cut to allow its transference.ln the standard model squares transfer were installed and splinted with acrylic resin (duralay reliance Dental Mfg Co. Wort ll). The acrylic resin extension involved the adjacent teeth occlusalsurfaces. After polymerization, transfer screws were unscrewed, connected to the implants analogues and adapted. To reproduceí casts, the acrylic resin extensions that limited the space, and the implants analogues fixed wit dental stone type IV (Durone; Dentsply Industry and trade Ltd, Petropolis, RJ, Brasil). Both standan model and reproduced casts (1,2 and 3) were photographed through buccal and occlusal surfaees with Nikon D50 camera, Macro lens 105mm and flash (Siqma], on stative and distance camera/object determined and maintained equal for all models photographed and measured by Corei Draw 3 program. Results: Were observed changes in the positions of all implants transferred in mesial direction(A, B and C), bucal direction (A and B) and vestibular direction (C). Conclusions: All values of implants transferred were smaller than 0,5 degree and the difference between the values of the Stander mode and transferred casts may be sufficient to influence the passive fit between the structures.

Use of stress analysis methods to evaluate the biomechanics of oral rehabilitation with implants.

Because the biomechanical behavior of dental implants is different from that of natural tooth, clinical problems may occur. The mechanism of stress distribution and load transfer to the implant/bone interface is a critical issue affecting the success rate of implants. Therefore, the aim of this study was to conduct a brief literature review of the available stress analysis methods to study implant-supported prosthesis loading and to discuss their contributions in the biomechanical evaluation of oral rehabilitation with implants. Several studies have used experimental, analytical, and computational models by means of finite element models (FEM), photoelasticity, strain gauges and associations of these methods to evaluate the biomechanical behavior of dental implants. The FEM has been used to evaluate new components, configurations, materials, and shapes of implants. The greatest advantage of the photoelastic method is the ability to visualize the stresses in complex structures, such as oral structures, and to observe the stress patterns in the whole model, allowing the researcher to localize and quantify the stress magnitude. Strain gauges can be used to assess in vivo and in vitro stress in prostheses, implants, and teeth. Some authors use the strain gauge technique with photoelasticity or FEM techniques. These methodologies can be widely applied in dentistry, mainly in the research field. Therefore, they can guide further research and clinical studies by predicting some disadvantages and streamlining clinical time.

Evaluation of stress patterns produced by implant-retained overdentures and implant-retained fixed partial denture.

The purposes of this study were to photoelastically measure the biomechanical behavior of 4 implants retaining different cantilevered bar mandibular overdenture designs and to compare a fixed partial denture (FPD). A photoelastic model of a human edentulous mandible was fabricated, which contained 4 screw-type implants (3.75 × 10 mm) embedded in the parasymphyseal area. An FPD and 3 overdenture designs with the following attachments were evaluated: 3 plastic Hader clips, 1 Hader clip with 2 posterior resilient cap attachments, and 3 ball/O-ring attachments. Vertical occlusal forces of 100 N were applied between the central incisor and unilaterally to the right and left second premolars and second molars. Stresses that developed in the supporting structure were monitored photoelastically and recorded photographically. The results showed that the anterior loading, the overdenture with 3 plastic Hader clips, displayed the largest stress concentration at the medium implant. With premolar loading, the FPD and overdenture with 3 plastic Hader clips displayed the highest stresses to the ipsilateral terminal implant. With molar loading, the overdenture with 3 ball/O-ring attachments displayed the most uniform stress distribution in the posterior edentulous ridge, with less overloading in the terminal implant. It was concluded that vertical forces applied to the bar-clip overdenture and FPD created immediate stress patterns of greater magnitude and concentration on the ipsilateral implants, whereas the ball/O-ring attachments transferred minimal stress to the implants. The increased cantilever in the FPD caused the highest stresses to the terminal implant.

Mobility, aesthetic, implants, and satisfaction of the ocular prostheses wearers.

During the process of facial rehabilitation, the mobility of ocular prostheses must be considered. Whereas some factors depend exclusively on the dentist, such as molding techniques and selection of material for denture construction, regarding ocular rehabilitation, factors, such as type of surgery, whether to adopt implants, and the use of lubricants, deserve special attention owing to their integration and their association with other factors pertaining exclusively to the patient. To establish harmony, and with the intention of aiding the dentist, after a discerning evaluation, the authors of this study report the factors that provide greater or less mobility to ocular prostheses and conceal the prosthesis in a more natural way, thereby contributing toward achieving a favorable aesthetic result in rehabilitations.

Incidents malignant neoplasias maxillofacial area.

Cancer is regarded as abnormal cellular multiplication; it is not controlled by the organism, and its cells present a differentiated DNA. Initially, the disease does not show clinical signs, but it can be diagnosed by laboratory examinations. When tumors are present in the maxillofacial area, the carrier can lose structures in this area, resulting to the carrier's social environment exclusion. This article aims to show incidences and causes of malignant neoplasias in the maxillofacial area.

Accuracy of impression techniques for implants. Part 2 - comparison of splinting techniques.

PURPOSE: The aim of this study was to compare splinting techniques for impression copings of osseointegrated implants with different angulations. MATERIALS AND METHODS: Replicas (N = 24) of a metal matrix (control) containing two implants at 90 degrees and 65 degrees in relation to the horizontal surface were obtained by using four impression techniques: Technique 1 (T1), direct technique with square copings without union in open trays; Technique 2 (T2), square copings splinted with dental floss and autopolymerizing acrylic resin; Technique 3 (T3),square copings splinted with dental floss and autopolymerizing acrylic resin, sectioned and splinted again with autopolymerizing acrylic resin; Technique 4 (T4), square copings splinted with prefabricated acrylic resin bar. The impression material was polyether. The replicas were individually scanned to capture the images, which were assessed in a graphic computation program. The program allowed the angulation between the bases of the replicas and the reading screws to be measured. The images of the replicas were compared with the matrix image (control), and the differences in angulations from the control image were calculated. The analysis of variance and the Tukey test for comparisons (p < 0.05) were used for statistical analysis. RESULTS: All groups showed significant differences in the implant angulations in comparison with the control group (p < 0.05). Group T1 showed the highest difference (1.019 degrees ) followed by groups T2 (0.747 degrees ), T3 (0.516 degrees ), and T4 (0.325 degrees ), which showed the lowest angular alteration compared to the control group. There were significant differences between inclined and straight implants in all the groups, except in group T4. CONCLUSIONS: Based on the results, the splinting of pick-up impression copings is indicated for osseointegrated implant impressions. The square copings splinted with a prefabricated acrylic resin bar presented the best results among the pick-up impression techniques evaluated in this study.

Evaluation of transfer impressions for osseointegrated implants at various angulations.

The accuracy of impressions that transfer the relationship of the implant to the metal framework of the prosthesis continues to be a problem. This study was designed to evaluate the accuracy of the transfer process under variable conditions with regard to implant analog angulations, impression materials, and techniques. Replicas (n = 60) of a metal matrix (control) containing four implants at 90 degrees , 80 degrees , 75 degrees , and 65 degrees in relation to the horizontal surface were obtained by using three impression techniques: T1-indirect technique with conical copings in closed trays; T2-direct technique with square copings in open trays; and T3-square copings splinted with autopolymerizing acrylic resin; and four elastomers: "P"-polysulfide; "I"-polyether; "A"-addition silicone; and "Z"-condensation silicone. The values of the implant analog angulations were assessed by a profilometer to the nearest 0.017 degrees , then submitted to analysis of variance for comparisons at significance of 5% (P < .05). For implant analog at 90 degrees , the material "A" associated with T2 and material "Z" with T3 behaved differently (P < .05) from all groups. At 80 degrees , all materials behaved differently (P < .01) with T1. At 75 degrees , when T1 was associated, materials "P" and "A" showed similar behavior, as well as materials "I" and "Z"; however, "P" and "A" were different from "I" and "Z" (P < .01). When T3 was associated, all experimental groups behaved differently among them (P < .01). At 65 degrees , the materials "P" and "Z" behaved differently (P < .01) from the control group with T1, T2, and T3; the materials "I" and "A" behaved differently from the control group (P < .01) when T1 and T2, respectively, were associated. The more perpendicular the implant analog angulation is in relation to the horizontal surface, the more accurate the impression. The best materials were material "I" and "A" and the most satisfactory technique was technique 3.

Perfil dos pacientes geriátricos portadores de prótese total / Geriatrics pacients profile carrying complete dentures

Este estudo teve como propósito avaliar uma amostra geriátrica de 240 prontuários de pacientes, atendidos pela disciplina de Prótese Total Faculdade de Odontologia de Araçatuba-UNESP, no período de 1980 a 2001, considerando-se que cada indivíduo apresentava sessenta anos ou mais na época do seu atendimento. As características de cada paciente foram analisadas quanto à cidade de origem, o sexo, o estado civil, estado de saúde geral, a cor dos dentes selecionados e o tipo de prótese confeccionada. Conclui-se que a maioria dos pacientes pertenciam ao sexo feminino, que a doença mais freqüente foi a hipertenção arterial e que o tipo de prótese mais confeccionada foi a bimaxilar