Magister Chirurgiae Dentium - MChD / Objectives: Temperature changes along an implant body have not been widely studied. The objectives of this in vitro study were (i) to establish if the temperature of the abutment influences the temperature of the implant surface, (ii) to establish the temperature transmission from abutment to implant body, and (iii) to establish for what abutment temperature the critical time/temperature threshold of 47oC for 1 minute at implant level is reached. Materials and method: Eight K-type thermocouples were attached to an abutment/implant configuration, mounted in a thermostatically controlled environment. The abutment was exposed to hot water. The temperature at each thermocouple along the implant was logged over a maximum period of 10 minutes using appropriate software. The test was repeated 200 times. A logistic regression model was used for the analysis of the time/temperature databases. Results: There was a positive correlation between the temperatures of the implant and its abutment, albeit with a time delay. Critical threshold values for bone necrosis were reached. The effective dose 50 was estimated at 62.3oC (95% confidence interval estimate): for an abutment temperature of 62.3oC there is a 50% chance that 47oC for 1 minute at implant level is reached. Conclusion: The results of this in vitro study support the hypothesis that abutment temperature is transmitted to a dental implant body. Results of in vitro studies should be interpreted with caution. However, clinicians should be aware of temperature changes along implants and the potential risk associated with this. / South Africa

L'implantologie dentaire est en constante évolution et l'objectif de ces innovations est d'assurer le succès de la thérapie implantaire. Des protocoles utilisant la fibrine riche en plaquettes (PRF) ont d'ailleurs trouvé des indications dans ce domaine. Le but de cette revue systématique est d'évaluer les effets du PRF sur la guérison osseuse et gingivale péri-implantaire. La question de recherche, basée sur la méthode PICOS, a été définie comme suit : "Chez les sujets nécessitant le remplacement d'une dent manquante par un implant dentaire, est-ce que l'utilisation du PRF démontre un bénéfice significatif comparativement à la pose d'un implant dentaire sans utilisation conjointe de PRF sur les résultats cliniques, basé sur des études humaines cliniques contrôlées? ". Les paramètres évalués incluaient la stabilité implantaire, les changements gingivaux dimensionnels, le remodelage osseux crestal et le taux de survie implantaire. Une recherche sur les bases de données MEDLINE (PubMed), Embase et Cochrane Library a été effectuée suivant une stratégie de recherche déterminée. Cinq études ont été retenues. Les résultats démontrent que l'ajout de PRF n'a généralement pas d'impact sur la stabilité implantaire. En ce qui concerne la profondeur au sondage, aucune différence significative n'a été obtenue entre les groupes. Parmi les trois études ayant mesuré la variation du niveau osseux crestal péri-implantaire, deux études rapportent que l'utilisation du PRF a réduit le remodelage osseux crestal alors qu'une étude n'a observé aucun effet positif. Le taux de survie implantaire était de 100% à l'exception d'une étude dans laquelle deux implants ont été perdus dans le groupe expérimental. La présente revue met en lumière l'effet modeste du PRF sur la guérison péri-implantaire. Il faudrait cependant prendre en considération le risque de biais élevé, la grande hétérogénéité des études et le nombre limité d'études fiables sur le sujet. Davantage d'études de bonne qualité sont nécessaires. / Dental implantology is in continuous evolution, and the objectives of these innovations are to ensure treatment success. Protocols using platelet-rich fibrin (PRF) have found indications in this field. The main goal of this systematic review is to assess the effects of PRF on peri-implant osseous and gingival healing. Based on the PICOS method, the research question has been defined as follows: " On subjects who need to replace a tooth with a dental implant, does PRF have a significant clinical benefit compared to dental implant placement without using PRF, based on human-controlled trials? " Assessed parameters included implant stability, dimensional gingival changes, crestal bone remodeling, and implant survival rate. A systematic literature search comprised three databases: MEDLINE (Pubmed), Embase, and Cochrane Library. Following a determined search strategy, five studies have been included. The results demonstrated that adding PRF generally has no positive effects on implant stability. No significant difference has been measured between groups when it comes to probing depth. Among the three studies that have evaluated peri-implant crestal bone height, PRF reduced crestal bone remodeling in two studies, whereas one study reported no positive effect. The implant survival rate was 100%, except for one study in which two implants were lost in the experimental group. This review highlights the modest positive effect of PRF on peri-implant healing. However, it is important to consider the high risk of bias, the high heterogeneity of the included studies, and the limited number of reliable studies. More research is necessary.

AIM: This systematic review enumerated the criteria used to determine the survival and success of the rehabilitation of the immediately loaded completely edentulous maxilla with surgically guided implant placement and restoration via fixed prostheses. By identifying these variables, the authors of this review hope to propose a new set of criteria that addresses current expectations of success and facilitates a better comparison of rehabilitation protocols. MATERIALS AND METHODS: The electronic databases PubMed and ScienceDirect were searched for clinical studies of restoration of complete maxillary implant supported fixed dental prostheses. The analysis was confined to prospective studies with a minimum follow-up of 3 years and a minimum number of 10 patients published prior to June 24th, 2021. RESULTS: An initial total of 781 publications was screened from the database searches. After further screening by title and abstract using PRISMA protocol and defined inclusion/exclusion criteria, nine (9) articles were reviewed. Analysis for survival and success criteria resulted in the following: 1. It was difficult to define a conclusion from the selected articles since there was little uniformity as to study design and the criteria used to evaluate the data. 2. High implant and implant supported fixed prosthesis survival could be achieved in the short-term (less than 5 years) when at least 4 implants were placed. 3. The type of surgical guide used for implant placement did not affect the survival and success of implants and implant supported fixed prostheses. 4. Immediate loading of the prostheses did not affect the success and survival of implant and implant supported fixed prostheses. 5. Widely accepted and reproducible criteria should be established to facilitate a better comparison of future materials, rehabilitation protocols. 6. The author proposes the following: Proposed Success Criteria (Ramesh 2023) Successful (Optimal Health): 1. No pain or tenderness associated with function 2. 0 mobility 3. Radiographic bone loss of 20% or less of implant length from initial surgery 4. No bleeding on probing or exudate 5. <4 mild/moderate complications Satisfactory: 1. No pain associated with function 2. 0 mobility 3. Radiographic bone loss 20-40% of implant length 4. Peri-implant mucositis Compromised: 1. May have sensitivity associated with function 2. 0 mobility 3. Radiographic bone loss >40% of implant length 4. Peri-implantitis Failed (clinical or absolute failure): Any of the following: 1. Pain associated with function 2. Mobility 3. Uncontrolled exudate 4. No longer in mouth 5. Non-restorable *This criteria borrows concepts from the Pisa Consensus 200 7. The following list of considerations is necessary to include in all future implant study designs. Proposed necessary factors: 1. Standardized protocols a. Guide design b. Guide fabrication c. Defining conventional versus other methods 2. Maintenance intervals a. Recall with yearly data collection b. Maintenance visits (at least twice yearly) 3. Individual implant review findings 4. Consistent follow up (as previously defined on page 41) a. Must include all the necessary variables to determine implant success 5. Implant location a. Anterior: cuspids and forward b. Posterior: bicuspids and back 6. Implant details - brand, length, diameter 7. Prosthesis design and fabrication, dictated by existing or regenerated bone base

The Breast Implant Lifetime Study at Virginia Tech, on which this thesis is based, seeks to develop methods and data for predicting the lifetime of saline-filled implants. This research developed Finite Element Analysis (FEA) models to evaluate the stresses that are present in the silicone breast implant material under different loading situations. The FEA work was completed using the commercial codes PATRAN and ABAQUS. PATRAN was used for pre- and post-processing, while ABAQUS was used for the actual analysis and to add fluid and contact elements not supported by PATRAN. Many different loading situations and constraints were applied to these models, as well as variations in the material and model properties. Varying the Poisson's ratio of the implant material from 0.45 to 0.49 did not make a significant difference in the results. Changing the elastic modulus of the implant material from the modulus of a Smooth implant to the modulus of a Siltex implant had a noticeable effect on the stress results, increasing the maximum stresses by almost 8%. Changing the modulus of the surrounding tissue had marked effects as well, with stiffer tissue (E=300 psi) decreasing the implant's stresses by about 60% as compared to softer tissue (E=100 psi). A ten percent decrease in implant thickness yielded a 17% average increase in stress experienced by the implant. For both the 2.5" radius and the 4" radius tissue models, using CAX4 elements produced higher overall stresses in the tissue with the same loading conditions. However, in the 2.5" tissue model, the implant itself experienced less stress with the CAX4 tissue than the CAX3 tissue. In the 4" tissue model, the implant experienced more stress when surrounded by the CAX4 tissue elements. These models will be combined with implant fatigue data to develop a life prediction method for the implant membrane. / Master of Science

Thesis (Ph. D.)--University of Alabama at Birmingham, 1998. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Alabama at Birmingham, 1998. / Includes bibliographical references.

Orientadores: Cecília Amélia de Carvalho Zavaglia, Vanessa Petrilli Bavaresco / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T02:53:41Z (GMT). No. of bitstreams: 1 Santos_FernandaHenriquesdos_M.pdf: 2590038 bytes, checksum: 807936f77ee66231cc661475d6643f25 (MD5) Previous issue date: 2011 / Resumo: Na área médica, para se desenvolver um dispositivo que funcione como implante, deve-se utilizar materiais que sejam compatíveis para funções específicas do corpo humano, e esses são classificados como biomateriais. Neste trabalho, foram determinados os parâmetros que serão aplicados ao laser de infravermelho (condutividade térmica do material, densidade do material e comprimento de onda do laser) utilizado na máquina de prototipagem rápida, a qual será usada para a fabricação do implante. Este implante será composto por um biomaterial polimérico a base de Polivinilalcool (PVAl) e, terá como objetivo a substituição da cartilagem articular mandibular. Estudos já avaliaram as propriedades mecânicas de hidrogéis poliméricos de PVAl mostrando sua aplicabilidade como reparadores da cartilagem articular em articulação de quadril, porém a articulação mandibular é submetida à aplicações de cargas superiores havendo a necessidade de melhoria de suas propriedades mecânica. A mistura física de dois ou mais polímeros é denominada blenda polimérica e seu objetivo é aperfeiçoar ou modificar as propriedades dos materiais adequando-as para uma aplicação específica. A literatura relata que PVAl e Polivinilpirrolidona (PVP) são polímeros miscíveis entre si e, quando não reticulados são solúveis em água. O PVP é um polímero amorfo e autolubrificante, e por isso, foi escolhido para melhorar as propriedades mecânicas do PVAl. Blendas nas composições de 90:10 de PVAl e PVP respectivamente, reticuladas via laser infravermelho utilizando concentração de 2,5% de termoiniciador cianovalérico foram caracterizadas via Espectroscopia do Infravermelho Médio, Calorimetria Exploratória Diferencial (DSC), Microscopia Eletrônica de Varredura (MEV) e Extração sol-gel. Através desses experimentos foram determinados os parâmetros do laser para posterior utilização na máquina de prototipagem rápida. Foi possível também realizar a cura do material através do laser de infravermelho. A cura foi confirmada através dos outros ensaios realizados / Abstract: In the medical area to develop a device that functions as an implant, one should use materials that are compatible for specific functions of the human body, and these are classified as biomaterials. In this study, we determined the laser parameters that will be applied to the infrared laser (thermal conductivity, material density and wavelength of the laser) in rapid prototyping machine, which will be used to manufacture the implant. This implant is a polymeric biomaterial based on polyvinylalcool (PVAl) and will aim to replace the articular cartilage of the mandible. Studies have evaluated the mechanical properties of polymeric hydrogels PVAl showing its applicability as repairing articular cartilage in hip joint, but the mandibular joint is subjected to loads greater than applications having the need to improve their mechanical properties. The physical mixture of two or more polymers is called polymer blend and its goal is to improve or modify the properties of materials making them suitable for a specific application. The literature reports that PVAl and PVP polymers are miscible and, when not crosslinked, are soluble in water. PVP is an amorphous polymer and selflubricating, and therefore was chosen to improve the mechanical properties of PVAl. Blends in the compositions of 90:10 PVAl and PVP respectively, crosslinked using infrared concentration of 2.5% termoiniciador cianovaléric were characterized by mid-infrared spectroscopy, Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and sol-gel fraction. Through these experiments were determined laser parameters for subsequent use in rapid prototyping machine. It was also possible to realize the cure of material through the infrared laser. The cure was confirmed by other tests / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-03T11:32:06Z No. of bitstreams: 1 gustavocanerecruz.pdf: 7258310 bytes, checksum: 5ef1068022f8966d891c48b9cc921f52 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-02T13:20:20Z (GMT) No. of bitstreams: 1 gustavocanerecruz.pdf: 7258310 bytes, checksum: 5ef1068022f8966d891c48b9cc921f52 (MD5) / Made available in DSpace on 2016-07-02T13:20:20Z (GMT). No. of bitstreams: 1 gustavocanerecruz.pdf: 7258310 bytes, checksum: 5ef1068022f8966d891c48b9cc921f52 (MD5) Previous issue date: 2012-12-18 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivos deste estudo retrospectivo foram analisar as taxas de sobrevivência de implantes cuneiformes angulados dentro de longo período de controle e identificar os fatores que podem afetar a sobrevivência destes implantes. Os prontuários de todos pacientes que receberam cuneiformes angulados entre 1992 e 2011 foram revisados de acordo com os seguintes critérios: idade, sexo, tabagismo, doença periodontal prévia, condições sistêmicas; localização, diâmetro, comprimento e angulagem dos implantes; datas de instalação, carregamento, últimos controles, procedimentos adaptativos e tipo de prótese. A sobrevivência foi analisada pelo método de Kaplan-Meier, assim como a identificação dos fatores de risco. Baseado nos resultados da análise univariada, os fatores de risco também foram identificados pelo método da regressão de Cox. Dos implantes revisados, 461 instalados em 120 pacientes (55 homens e 65 mulheres) preencheram os critérios para serem incluídos neste estudo. A média de sobrevivência foi de 148,6±3,9 meses. A sobrevivência global acumulada foi de 95,2% e 92,1% aos 5 e 10 anos, respectivamente. A localização (P =,017), o diâmetro (P =,044) e o ângulo (P =,024) foram identificados como fatores de risco significantes para a perda dos implantes na análise univariada. Na análise multivariada, apenas a localização permaneceu significativa. Implantes cuneiformes angulados são utilizados em locais onde o uso de implantes retilíneos de dimensões padrão não é possível ou não indicado. Portanto, embora as taxas de sobrevivência sejam semelhantes, a sobrevivência dos implantes cuneiformes angulados não deve ser comparada à destes implantes retilíneos. Ela deve ser comparada ao sucesso de procedimentos reconstrutivos ou métodos alternativos como os implantes extra-curtos. Implantes cuneiformes angulados representam um alternativa efetiva para locais onde o uso de implantes retilíleos padrão não está indicado. Devido a características dos resultados e aspectos clínicos, apenas a localização foi considerada um fator de risco significativo para a sobrevivência dos implantes estudados. / The purpose of this study was to analyze retrospectively the survival rate of wedge-shaped angled implants over a long-term follow-up period and to identify factors that affect this survival. The charts and radiographs of all patients who received wedge-shaped angled implants between 1992 and 2011 were examined according to the following criteria: age, gender, tobacco smoking habbit, previous periodontal disease, systemic conditions; location, diameter, length and angulation of the implant, time of placing, loading and last follow-ups; adaptative procedures and type of prosthesis. Survival wan analysed by Kaplan-Meier method, as well as identification of risk factors. Based on the univariate analyses results, risk factors where also identified by Cox regression method. Of the implants reviewed, 461 in 120 patients (55 mens and 65 womans) met the criteria for inclusion in this study. Mean survival was of 148.6±3.9 months. Global cumulative survival rates where 95.2% and 92.1% at 5 and 10 years, respectively. Location (P = .017), diameter (P = .044) and angle (P = .024) were identified as significative risk factor for implant loss at the univariate analysis. At the multivariate analysis, only the location remained significative. Wedge-shaped angled implants are intended to be used in situations that the use of standard dimesions straight implants are not possible. So, although their survival rates are similar, wedge-shaped angled implants survival must be compared to those straight implants, but to the success of reconstrutive procedures or alternative methods like extra-short implants. Wedge-shaped implants represent an effective alternative to sites that are not indicated to standard straight implants placement. Due to results caractheristics and clinical implications, only location was considered as a significant risk factor for implant survival.

No description available.

published_or_final_version / Dentistry / Master / Master of Dental Surgery