Prótese e implante sobre enxerto alógeno: análise histológica e acompanhamento clínico: radiográfico por 8 anos / Prosthesis and implant on allogenic graft: histological analysis and clinical: radiographic follow-up for 8 years

Este relato de caso clínico tem como objetivo descrever a utilização de osso alógeno na reconstrução de maxila atrófica para posterior reabilitação com prótese fixa metalocerâmica sobre implantes, fazer uma análise histológica do tecido ósseo enxertado e descrever o acompanhamento clínico e radiográfico por 8 anos. Uma paciente de 54 anos, com edentulismo parcial e atrofia moderada-a-severa na maxila, apresentou-se para tratamento demonstrando muito interesse em receber prótese sobre implantes. Após exame clínico e radiográfico, foi realizada montagem dos modelos de estudo em ASA para enceramento diagnóstico e obtenção de um guia multifuncional (tomográfico/ cirúrgico). A tomografia indicou a necessidade de reconstrução óssea maxilar. Procedeuse então à aposição de blocos de osso alógeno para aumento horizontal nas regiões anterior e posterior da maxila. Um dos blocos foi triturado e utilizado para levantamento do assoalho do seio maxilar no lado esquerdo. Dez meses depois, uma nova tomografia foi solicitada, utilizando o mesmo guia inicial, e os implantes instalados, utilizando o guia multifuncional como guia cirúrgico. Neste momento, material ósseo foi coletado na interface osso enxertado/osso nativo com uma broca trefina. Os resultados histológicos demonstraram viabilidade das células ósseas no enxerto, além da presença de vasos sanguíneos. Após o tempo necessário para osseointegração, procedeu-se com tratamento protético. Nenhuma complicação foi relatada até oito anos de controle. A sequência de tratamento proposta forneceu bons resultados estéticos e funcionais. Concluiu-se, então, que o emprego de osso alógeno é uma alternativa viável para a reconstrução de rebordos alveolares severamente reabsorvidos(AU)

This clinical case report aims to describe the use of allogeneic bone in the atrophic maxilla reconstruction for subsequent rehabilitation with a fixed metal-ceramic prosthesis on implants; to perform a histological analysis of the grafted bone tissue; and to describe the clinical and radiographic monitoring for 8 years. A 54-year-old patient, with partial edentulism and moderate-to-severe atrophy in the maxilla showed great interest in receiving implant prostheses. After c linical and radiographic examination, the ASA study models were assembled for diagnostic waxing and a multifunctional guide (tomographic / surgical) was obtained. Tomography indicated the need for maxillary bone reconstruction. Allogeneic bone blocks were then placed for horizontal enlargement in the anterior and posterior regions of the maxilla. One of the blocks was crushed and used to lift the floor of the maxillary sinus on the left side. Ten months later, a new tomography was requested, using the same initial guide, and the implants installed, using the multifunctional guide as a surgical guide. At this time, bone material was collected at the grafted bone / native bone interface with a trephine drill. Histological results demonstrated viability of bone cells in the graft, besides the presence of blood vessels. After the necessary time for osseointegration, a prosthetic treatment was performed. No complications were reported up to eight years of control. The propose treatment sequence provided good aesthetic and functional results. It was concluded, then, that the use of allogeneic bone is a viable alternative for the reconstruction of severely reabsorbed alveolar edges(AU)

Comparative clinical study using short and conventional implants in bilateral jaw posteriors

Abstract The aim of this study was to clinically and radiographically compare extra short and standards implants. Forty-two implants were installed in 10 selected patients. They received prosthetic loading only after the conventional waiting time for osseointegration and the prostheses were made ferulized. Radiographic shots were performed to evaluate vertical and horizontal bone losses at times T1 (prosthetic installation), T2 (6 months follow-up) and T3 (12 months follow-up). Biological parameters such as bone level around the implants (CBL) were evaluated, CBL alteration (CBLC), total crown length (TCL) and implant/crown ratio (ICR) were digitally calculated. All implants included in the study were submitted to the analysis of the implant stability quotient (ISQ) at the time of implant installation (T0) and at 12 months of prosthetic function (T3). Data were statistically tested. The ICR was higher in the test group than in the control group (p<0.0001). The CBL measurements at the beginning of the study were 0.21±0.19 mm and 0.32±0.38 mm and at 12 months 0.65±0.24 mm and 0.87±0.34 mm, respectively in the test and control groups. CBLCs and CBL were similar at all times (p>0.05). No correlation was found between CBLC and ICR parameters, as well as between ISQ and implant length. We may conclude that standards and extra short implants can provide similar clinical results in prosthetic rehabilitation of the atrophic jaw over 12 months of follow-up.

Resumo O objetivo deste estudo foi comparar clínica e radiograficamente implantes extra curtos e padrões. Quarenta e dois implantes foram instalados em 10 pacientes selecionados. Eles receberam carga protética somente após o tempo de espera convencional para a osseointegração e as próteses foram feitas ferulizadas. As imagens radiográficas foram realizadas para avaliar as perdas ósseas verticais e horizontais nos tempos T1 (instalação protética), T2 (6 meses de acompanhamento) e T3 (12 meses de acompanhamento). Parâmetros biológicos como nível ósseo ao redor dos implantes (CBL) foram avaliados, alteração CBL (CBLC), comprimento total da coroa (TCL) e relação implante / coroa (ICR) foram calculados digitalmente. Todos os implantes incluídos no estudo foram submetidos à análise do quociente de estabilidade do implante (ISQ) no momento da instalação do implante (T0) e aos 12 meses de função protética (T3). Os dados foram testados estatisticamente. A ICR foi maior no grupo teste do que no grupo controle (p<0,0001). As medidas de CBL no início do estudo foram de 0,21±0,19 mm e 0,32±0,38 mm e em 12 meses 0,65±0,24 mm e 0,87±0,34 mm, respectivamente nos grupos teste e controle. CBLCs e CBL foram semelhantes em todos os momentos (p>0,05). Não foi encontrada correlação entre os parâmetros CBLC e ICR, bem como entre o ISQ e o comprimento do implante. Podemos concluir que padrões e implantes extra curtos podem fornecer resultados clínicos semelhantes na reabilitação protética da mandíbula atrófica ao longo de 12 meses de acompanhamento.

Three-Dimensional Finite Element Analysis on Different Implant Prostheses for Labial Bone Graft / 医用生物力学

Objective To analyze the influence of bone graft and prosthesis on stress distributions in internal structure and surrounding bone tissues of implant prosthesis. Methods Two models of maxillary central incisor implants supported by two kinds of labial alveolar bone models were established, which were restored by porcelain fused metal (PFM) crown and zirconia all-ceramic crown, respectively. The mechanical loads were applied to analyze the influence of bone graft and two different prostheses on stress distributions of internal structure of the implant and interface between the implant and bone. Results In bone graft group, the stress in labial part of the retaining screw and labial bone tissues of the implant was much lower than that in non-bone graft group, but the stress of the implant neck was higher in bone graft group than that in non-bone graft group. Under the same bone condition, the stress of zirconia all-ceramic crown group on lip side of the retaining screw was greater than that of PFM crown group. Conclusions Prosthesis have little effect on stress distributions of internal structure and surrounding bone tissues of implant prosthesis, but the difference of labial bone affected by bone grafts can affect stress concentrations of the retaining screw and the implant-bone interface.

Three-dimensional finite element analysis of different implant prostheses in maxillary anterior teeth region under different occlusal relationships / 中国组织工程研究

BACKGROUND: In the treatment with dental implant prosthesis, the stress distribution of marginal bone and implant-bone interface Is affected by the factors of restoration and occlusion. The Internal structure and the stress distribution of Implant-bone Interface determine the long-term life of the implant and the stability of the marginal bone. OBJECTIVE: To analyze the effects of zirconia-based all-ceramic crown and Co-Cr alloy porcelain ceramic crown on the stress distribution of implant-bone interface, implant, prosthesis abutment, retention screw, and the inner structure in three occlusal relationships. METHODS: Using Mimics 17.0 software, the implant model of maxillary central incisor was established based on the cone beam CT of a patient undergoing prosthesis implantation Into the maxillary central incisor. Two kinds of three-dimensional finite element models of zirconia-based all-ceramic crown and Co-Cr alloy porcelain ceramic crown were constructed. The edge to edge occlusion, normal occlusion and deep overbite were simulated to analyze the stress distribution of Implant structure and the Implant-bone Interface in the three occlusal relationships. RESULTS AND CONCLUSION: (1) In the Co-Cr alloy porcelain ceramic crown group, when the occlusal relationship changed from the edge-to-edge occlusion to the normal occlusion and deep overbite relationships, the stress at the occlusal point of the prosthesis increased correspondingly, and the stress at the abutment, Implant and the Implant-bone Interface decreased. In the normal occlusal relationship, the stress at the retention screw was more concentrated than that in the other two occlusal relationships, and its peak value of the equivalent stress was higher. (2) In the zirconia-based all-ceramic crown group, when the occlusal relationship changed from edge-to-edge occlusion to the normal and deep overbite relationships, the stress peaks of the abutment, implant and implant-bone interface decreased gradually. In the normal occlusal relationship, the stress peaks of the occlusal point and the retention screw were higher than those in the other two occlusal relationships. (3) In the edge-to-edge occlusion relationship, the peak of equivalent stress at the occlusal point of the implant prosthesis in the Co-Cr alloy porcelain ceramic crown group was slightly higher than that in the zirconia-based all-ceramic crown group. The peaks of equivalent stress of the abutment, retention screw, Implant, and Implant-bone Interface in the Co-Cr alloy porcelain ceramic crown group were slightly lower than those in the zirconia-based all-ceramic crown group. In the normal occlusal relationship, the peak of equivalent stress at the neck of the implant in the Co-Cr alloy porcelain ceramic crown group was slightly higher than that in the zirconia-based all-ceramic crown group. In the deep overbite relationship, the peaks of the equivalent stress at the occlusal site of the implant prosthesis and the neck of the implant in the Co-Cr alloy porcelain ceramic crown group were higher than those in the zirconia-based all-ceramic crown group. The peaks of equivalent stress of the abutment, retention screw, and implant-bone interface In the Co-Cr alloy porcelain ceramic crown group were slightly lower than those in the zirconia-based all-ceramic crown group. (4) These results showed that different occlusal relationships and different upper structures of the implant prosthesis affected the stress distribution in each part of the implant and at the implant-bone interface. This finding may provide a reference for the prediction of long-term complications of implant prosthesis.

Clinical application and complications of short implants (≤6 mm) / 口腔疾病防治

@#Short implants can be used as an alternative in cases of insufficient vertical bone volume after dentition defect or absence of dentition to simplify or avoid bone augmentation procedures. Short implants (≤ 6 mm) are reported to have a mean survival rate of 96% after a period of 1-5 years in function and have been widely used in cases of dentition defects or absence of dentition. Compared with conventional implants (≥ 10 mm) combined with bone augmentation procedures, short implants have fewer surgery-related complications, less marginal bone loss, shortened treatment times and reduced costs, and are preferred by patients. Due to a lack of evidence, a high crown-implant ratio should not be an obstacle for the use of short implants. In addition, most of the current literature has not enough follow-up time, the long-term implant survival data of short implants remain unclear. To improve the clinical outcomes of short implants, attention should be paid to the implant site, bone quality, and occlusal force as well as to the presence of oral health maintenance, periodontal diseases and habits through a careful intraoral and radiographic examination. The choices of wider implant use and splint restoration are recommended, occlusal force should be paid attention during implant maintenance. Inappropriate stress on restorations should be avoided. Future studies should be focused on the long-term clinical outcomes of short implants.

Repairment of abutment and abutment screw fracture in implant prosthesis: A case report / 대한치과보철학회지

Dental implants are an effective and predictable treatment for restoration of missing teeth. However, as the use of implants increases, complications are also increasing. The mechanical complications are not only highly frequent, but also increasing as life span of an implant increases, thus, solutions should be prepared. In this report, we will present a case dealing with abutment fracture and abutment screw fracture which are the most common mechanical complication of the implant, focusing on preserving and reusing existing components by reconstructing only the damaged parts.

Application of virtual surgical planning in the surgical treatment of osteoradionecrosis of mandible / 口腔疾病防治

Objective @#To analyze the value of virtual surgical planning in the surgical treatment of osteoradionecrosis of the mandible and to provide a reference for clinical practice.@*.Methods @#From September 2017 to June 2018, 13 patients with mandibular osteoradionecrosis were evaluated preoperatively using the 3D virtual surgery software CMF Proplan 2.0. The surgical guide was designed and 3D printed. Bone resection, fibula shaping and bone graft localization were completed during the operation. In some cases, implants were implanted at the same time, and denture restoration was completed 3 to 6 months after surgery. Patients’ general information, perioperative data, and efficacy evaluation were analyzed.@*Results@#All patients underwent surgery successfully. The survival rate of the free fibula musculocutaneous flap was 100% (13/13), and one patient had complications (partial necrosis at the edge of the flap). The follow-up period was 7 to 15 months, and the median time was 10 months. All patients achieved a healing effect. The number of cases with an increase in mouth opening ≥ 1 cm, 0.5 cm ≤ mouth opening increase < 1 cm, and mouth opening increase < 0.5 cm were 5, 6, and 2, respectively. An imaging examination showed that 12 patients had good bone healing, and 1 patient did not completely heal 7 months after operation. The denture restoration was 92.3% (12/13), of which 3 cases were implanted and repaired at the same time. The average chewing efficiency was 56.11% ± 7.12% (42.03%-67.83%).@*Conclusion@#Virtual surgical planning is an effective method for the surgical treatment of mandibular osteoradionecrosis, which can reduce the risk of surgery and more effectively perform mandibular shape and function repair.

Effects of cementless fixation of implant prosthesis: A finite element study

PURPOSE: A novel retentive type of implant prosthesis that does not require the use of cement or screw holes has been introduced; however, there are few reports examining the biomechanical aspects of this novel implant. This study aimed to evaluate the biomechanical features of cementless fixation (CLF) implant prostheses.MATERIALS AND METHODS: The test groups of three variations of CLF implant prostheses and a control group of conventional cement-retained (CR) prosthesis were designed three-dimensionally for finite element analysis. The test groups were divided according to the abutment shape and the relining strategy on the inner surface of the implant crown as follows; resin-air hole-full (RAF), resin-air hole (RA), and resin-no air hole (RNA). The von Mises stress and principal stress were used to evaluate the stress values and distributions of the implant components. Contact open values were calculated to analyze the gap formation of the contact surfaces at the abutment-resin and abutment-implant interfaces. The micro-strain values were evaluated for the surrounding bone.RESULTS: Values reflecting the maximum stress on the abutment were as follows (in MPa): RAF, 25.6; RA, 23.4; RNA, 20.0; and CR, 15.8. The value of gap formation was measured from 0.88 to 1.19 µm at the abutmentresin interface and 24.4 to 24.7 µm at the abutment-implant interface. The strain distribution was similar in all cases.CONCLUSION: CLF had no disadvantages in terms of the biomechanical features compared with conventional CR implant prosthesis and could be successfully applied for implant prosthesis.

Posterior single implant prosthesis using scannable healing abutment / 대한치과보철학회지

Accurate impression taking for the success of implant prosthesis is a very important process. Methods of taking implant impression include the conventional method using impression coping and impression material, and the digital method using an intraoral scanner and scanbody. However, the impression coping or the scanbody must install after remove healing abutment. Because of this, the dentist must repeat the process of removing and installing the healing abutment, the impression coping or the scanbody several times. In addition, the impression coping or the scanbody rises higher than the occlusal surface, so the patient has the inconvenience of constantly maintaining the open state. Recently, a scannable healing abutment, which can be scanned by a intraoral scanner directly, without the need to remove the healing abutment by applying a scannable part of the scanbody to the healing abutment, was introduced. We present a case of single posterior implant prosthesis using a scannable healing abutment.

Atratividade do sorriso: um método simples para melhorar a percepção visual do dentista: desenvolvimento e teste-piloto com estudantes de pós-graduação / Smile attractiveness: a simple method to improve the dentist's visual perception: development and pilot test with postgraduate students

Objetivos: melhorar a percepção do dentista sobre a atratividade do sorriso através de avaliações objetivas. Material e métodos: fotografias frontais de sorrisos (envolvendo a área dos caninos) foram aleatoriamente escolhidas e dispostas em dois sentidos verticais variados (nivelado, abaixo) numa guia personalizada contendo quatro molduras labiais do sorriso (fino, médio, grosso, invertido). Os aspectos que influenciam a atratividade do sorriso (PD = proporção dentária, PV = posicionamento vertical dentário, EL = espessura labial, FG = festonamento gengival) também foram incluídos e uma nota final geral atribuída ao sorriso geral (SG). Adicionalmente, o formulário do exercício continha a opção "existe um implante?" e "qual sua localização?". Todos os itens foram avaliados através de escalas de Likert. A prevalência de respostas foi calculada para cada item. O teste de Wilcoxon (alfa = 5%) foi usado para verificar a possibilidade de diferença de opinião entre os nivelamentos horizontais e para uma mesma moldura de sorriso. Os níveis de confiabilidade (concordância absoluta = ICC e responsividade = Cronbach alfa) também foram avaliados. Resultados: um teste-piloto foi conduzido com 16 estudantes. Trinta e duas combinações foto/moldura labial foram geradas e apresentadas de forma randomizada. A avaliação geral do sorriso ficou em: pobre (11/32), mediano (6/32), bom (15/32) e muito bom (1/32). O número de acertos da possível posição do implante foi 13 em 32 tentativas. Diferenças estatisticamente significativas entre os nivelamentos foram observadas nas situações 1/17 (p=0,0001), 13/29 (p=0,02), 2/18 (p=0,0002), 6/22 (p=0,0001), 14/30 (p=0,0001), 7/23 (p=0,01) e 15/31 (p=0,039). Os maiores coeficientes de ICC e Cronbach alfa foram vistos para o sorriso geral e FG. Conclusão: a percepção visual do dentista pode ser treinada mudando-se a moldura labial e o nivelamento vertical dos dentes e é influenciada pelo festonamento gengival. O teste se mostrou útil na verificação da atratividade do sorriso.

Objectives: to improve the perception of the dentist on the smile attractiveness through objective evaluations. Material and methods: frontal photographs of smiles (involving the canine area) were randomly chosen and arranged in two different vertical directions (leveled, below) in a personalized guide containing four lip architectures (thin, medium, thick, inverted). The aspects that infl uence the smile attractiveness (PD = dental proportion, PV = vertical tooth position, EL = lip thickness, GS = gingival scalloping) were also included and a general final score attributed to the general smile (SA). Additionally, the exercise form contained questions such as "is there an implant?" and "what is your location?". All items were assessed using Likert scales. The prevalence of responses was calculated for each item. The Wilcoxon test was used to verify the possibility of differences between the horizontal leveling for the same smile architecture. The reliability levels (absolute agreement = ICC and responsiveness = Cronbach alpha) were also evaluated. Results: a pilot test was conducted with 16 students. Thirty-two photos/lip architecture combinations were generated and presented at random. The overall smile rating was: poor (11/32), average (6/32), good (15/32), and very good (1/32). The number of positive responses for implant position was 13 in 32 trials. Statistically significant differences were observed in the combinations 1/17 (p=0.0001), 13/29 (p=0.02), 2/18 (p=0.0002), 6/22 (p=0.0001), 14/30 (p=0.0001), 7/23 (p=0.01) and 15/31 (p=0.039). The highest ICC and Cronbach alpha values were seen for the general smile attractiveness (SA) and GS. Conclusion: the visual perception can be trained by changing the lip architecture and vertical leveling of the teeth and is influenced by gingival scalloping. This test proved to be useful in verifying the smile attractiveness.

Technical complications associated with implant prostheses in terms of reason, prevention, and management / 口腔疾病防治

@#Technical complications associated with implant prostheses include abutment or screw loosening, abutment or screw fractures, implant fractures, fracture of the veneering material and loss or misfitting of retention equipment. In this review, implant prostheses are classified as implant-supported single crowns (SCs), implant-supported fixed dental prostheses (FDPs) or implant-supported fixed complete dentures (FCDs). We evaluated the incidence of technical complications based on the clinical literature published after 2000. Then, we analyzed the reason, prevention and clinical management of abutment or screw loosening, abutment or screw fractures, implant fractures, fracture of the veneering material and loss or misfitting of retention, to reduce the incidence of complications and provide guidance for future oral implant treatment.

Desajuste vertical entre implante de hexágono interno e pilares Ucla totalmente calcináveis e com base de CoCr após a fundição pelo processo convencional / Vertical misfit between internal hexagon implants and Ucla burnout and CoCr prefabricated base abutments after conventional casting procedures

Objetivo: avaliar, por meio de um microdurômetro, o grau de desajuste na adaptação de pilares Ucla em implantes. Material e métodos: foram utilizados dez implantes de hexágono interno de plataforma regular, e seus respectivos componentes protéticos do tipo Ucla com antirrotacional, como seguem: dez pilares Ucla totalmente calcináveis e dez pilares Ucla com base de CoCr. Todos os pilares Ucla foram fundidos pelo mesmo laboratório de prótese e pelo mesmo processo laboratorial. Cada implante recebeu apenas dois pilares, que foram anexados por meio de um parafuso de titânio quadrado utilizando-se torque de 30 Ncm com torquímetro manual. Cada conjunto implante/pilar recebeu quatro marcações aleatórias em torno da circunferência, na qual foram feitas as medições do espaço existente entre as peças utilizando uma lupa estereoscópica de 100 vezes de aumento. Resultados: os resultados obtidos mostraram diferenças significativas entre os grupos submetidos ao teste Mann-Whitney (p < 0,05). Conclusão: o pilar Ucla com base de CoCr apresentou menor desajuste marginal vertical, quando comparado ao pilar Ucla totalmente calcinável, após o processo de fundição nos implantes de hexágono interno.

Objective: to evaluate, using a microhardness device, the misfit between Ucla abutments and internal hex implants. Material and methods: 10 internal hex implants received 10 Ucla burnout and 10 Ucla abutments with CoCr collar. All the abutments were cast in the same laboratory and under the same protocol. A square-head titanium screw was tightened to a 30 Ncm using a manual wrench. Each abutment/implant set receive four random markings around its perimeter. A stereoscopic lens was used to investigate the misfi t at 100 magnification. Results: there was a statistically significant difference between tested abutments (Mann-Whitney p < 0.05). Conclusion: the Ucla abutment with the CoCr collar presented less vertica misfit values after casting for internal hex dental implants.

Clinical study on the comparison of gold and zirconia wear in an implant-supported fixed prosthesis

PURPOSE: The purpose of this study was to compare and analyze the wear of a prosthesis for 6 months after restoration with implant-supported fixed dental prosthesis made of either zirconia or gold. MATERIALS AND METHODS: This study was conducted on patients requiring implant-supported fixed dental prostheses on first or second molar from January, 2015 to January, 2016. A total of 47 prostheses and antagonists were examined. Occlusal surface was recorded by impression of each prosthesis and antagonist 1 week and 6 months after prosthesis delivery. The digital files were created by impression scan. Occlusal shapes of 1 week and 6 months were compared and wear of prostheses and antagonists was analyzed. The Mann-Whitney test was used to analyzed the result data underwent normality test using SPSS (Version 23.0, IBM Corporation) RESULTS: Mann-Whitney test revealed that there was no statistically significant difference in the median amount of mean vertical wear for 6 months in zirconia (50.84 μm) and gold (42.84 μm) prostheses (P > 0.05). When the opposing teeth were natural, the median amount of mean vertical wear of zirconia and gold prostheses was 47.72 μm and 41.97 μm, respectively, and the median amount of mean vertical wear of enamel was 47.26 μm and 44.59 μm, respectively. Statistical analysis showed no significant difference (P > 0.05). CONCLUSION: Despite the short study period and the small number of experimental groups, zirconia and gold showed no significant difference in wear during the first 6 months. Opposing natural enamel also showed no significant difference in the wear.

Esthetic implant restoration in the maxillary anterior missing area with palatal defect of the alveolar bone: a case report

It is challenging to produce esthetic implant restoration in the narrow anterior maxilla region where insufficient volume of alveolar bone could limit the angle and position of implant fixture, if preceding bone augmentation is not considered. Ideal angle and position of implant fixture placement should be established to reproduce harmonious emergence profile with marginal gingiva of implant prosthesis, bone augmentation considered to be preceded before implant placement occasionally. In this case, preceding bone augmentation has been operated before esthetic implant prosthesis in narrow anterior maxilla region. Preceded excessive bone augmentation in buccal area allowed proper angulation of implantation, which compensates unfavorable implant position. Provisional restorations were corrected during sufficient period to make harmonious level of marginal gingiva and interdental papilla. The definite restoration was fabricated using zirconia core based glass ceramic. Functionally and esthetically satisfactory results were obtained.

Plaque accumulation beneath maxillary full-arch implant-supported fixed prostheses / 口腔疾病防治

Objective@#To evaluate the plaque distribution on the fitting surface of fixed implant prostheses which were supported by multi-unit abutment. @*Methods @# 21 patients with maxillary full-arch implant-supported fixed prostheses were collected. Plaque accumulation at the fitting surfaces were evaluated 3 months after restoration, by analyzing the digital photographs recorded by Imag e J 2.1.4.7.@*Results@#The average percentage of area covered with plaque was (46.13 ± 7.23)%. Plaque accumulation on the buccal and palatal area were (41.53 ± 3.08) and (53.76 ± 3.07)% respec⁃ tively, with a significant difference (t = 16.750, P < 0.001). The free area (71.86 ± 2.00) % was significantly higher than the anterior area (48.85 ± 2.09)% (t = 40.445, P < 0.001), andalso the middle area (49.33 ± 0.98)% (t = 47.124 , P < 0.001). The plaque percentage was higher when the distance between the implants was shorter.@*Conclusion@#To Minimize the palatal extension and free area of the prostheses, and to maximize the distances between the implants, were helpful to improve the oral hygiene control. It might be the key to keep a good outcome of the maxillary full-arch implant-supported fixed prostheses.

Encía artificial en prótesis implantoasistida: indicaciones y aplicaciones clínicas / Artificial gingiva in implant-supported prosthesis: indications and clinical applications

En la rehabilitación odontológica integral actual, hay que evaluar los parámetros clínicos para una restauración sobre implantes dentales. El tratamiento del sector anterior de ambos maxilares en situaciones clínicas complejas, hace que el éxito sea difícil de alcanzar, inclusocuando todos los objetivos establecidos de diagnóstico y de planificación del tratamiento, sean respetados y puedan realizarse. El objetivo es imitar la apariencia de los dientes contiguos para simular la dentición natural, con un enfoque en la estética de los tejidos gingivales adyacentes a las restauraciones sobre implantes. En los casos en que el tejido óseo y la pérdida mucogingivales marcada y procedimientos quirúrgicos adicionales no son viables, se requerirá de tratamientos alternativos. Uno de ellos podría ser el uso de encía artificial para reconstruir las deficiencias de tejidos duros y blandos. Este artículo describe diferentes indicaciones y aplicaciones clínicas de la encía artificial en prótesis implanto asistida.

In the current comprehensive dental rehabilitation, clinical parameters for success restoration on dental implants must be evaluated.Treatment of both anterior maxillary and mandibular jaws in complex clinical situations makes success difficult to achieve, even when allestablished goals in diagnosis and treatment planning, are respected and can be made.The goal is to mimic the appearance of the adjacent teeth to simulate natural dentition, with a focus on the aesthetics of the gingival tissuesnext to implant restorations. In cases where the bone and mucogingival tissues loss are marked and additional surgical procedures shouldnot be viable, it will require alternative treatment options. One of them could be the use of artificial gingiva to rebuild the deficiencies ofhard and soft tissues.This article describes different indications and clinical applications in artificial gum assisted implant prosthesis.

A clinical retrospective study on Osstem MS one-stage implant restoration of small edentulous space in the mandibular anterior region / 实用口腔医学杂志

Objective:To assess the clinical efficacy of two different diameter Osstem MS one-stage implant restoration of small edentu-lous space in the mandibular anterior region.Methods:85 patients were treated by Osstem MS one-stage implant with the diameter of 2.5 mm(n =66)and 3.0 mm(n =66)respectively for the restoration of small edentulous space in mandibular anterior region.The mesi-al and distal marginal bone level and soft tissue were statistically analyzed after 1 2 and 24 months of functional load.The implant survival rate was evaluated according to Wheeler's survival criteria.Results:The survival rate of the implants was 1 00%.The mean changes in marginal bone level(mm)on the mesial side of 2.5 mm and 3.0 mm diameter implants were 0.275 ±0.638 and 0.098 ±0.31 9,distal aspects were 0.360 ±0.588 and 0.1 09 ±0.323 after 1 2 months of functional load;while 0.299 ±0.672 and 0.099 ±0.31 8,0.381 ± 0.581 and 0.1 07 ±0.31 9 after 24 months of functional load.The mesial and distal marginal bone loss of 2.5 mm diameter implant was greater than that of 3.0 mm after 1 2 and 24 months of functional load(P 0.05).No relevant complication of peri-implant soft tissue was shown.Conclusion:Favorable clinical effects including function and aesthetics can be achieved by Osstem MS one-stage implant with the diameter of 2.5 mm or 3.0 mm for the restoration of small edentulous space in the mandibular anterior region,however,the mar-ginal bone loss was greater around 2.5 mm diameter implant.

Implant prosthesis using intraoral scanner: Case Report / 대한치과보철학회지

Accuracy is the most important thing in implant prosthesis, for this reason it is essential procedure to check the accuracy of impression taking. However, impression material has its own error and the error occurs in model-making procedure. As an alternative way to this, using intraoral scanner can be suggested and many studies were issued reporting that there's no statistically significant difference in accuracy between intraoral scanner and conventional impression. Therefore, the purpose of this study is to report the process of making of implant prosthesis using intraoral scanner, which is more convenient, fast, accurate compared with conventional method.

Clinical study on the food impaction between implant prostheses and adjacent teeth / 대한치과보철학회지

PURPOSE: The purpose of this study was to investigate the food impaction between implant prostheses and adjacent natural teeth. MATERIALS AND METHODS: For this study, 51 patients with food impaction were selected and investigated mobility, tightness of contact area, gingival index, plaque index, attachment loss, alveolar bone level, proximal caries, marginal ridge distance and occlusal relationships. RESULTS: Food impaction was found in the upper teeth (60.7%) more than the lower teeth (39.2%). Food impaction was occurred on mesial side of implant prostheses (86.2%) more than distal side (13.7%). Food impaction was mostly found in loose or open contact area (94.2%). Food impaction was frequent on stepped relationship between implant and adjacent teeth. CONCLUSION: Treatment plan should include proper adjacent and antagonistic occlusal plane and occlusal surface, to prevent food impaction, and the plan should include less adjacent tooth mobility with proper tightness between implant prostheses and adjacent teeth.

Submucosal zirconia implant prosthesis fabricated with CAD/CAM / 대한치과보철학회지

They have been recently introduced many aesthetic implant prosthesis using with zirconia and CAD/CAM. However, there are many limitations in their gingival and occlusal region. In this case, submucosal zirconia implant prosthesis were fabricated with CAD/CAM system. The connection of these screw cement retained prosthesis and titanium abutment was designed to 1mm above the fixture. The clinical results were satisfactory on the aesthetics and function.