Accuracy of digital guided implant surgery: expert consensus on nonsurgical factors and their treatments / 口腔疾病防治

@#The standardized workflow of computer-aided static guided implant surgery includes preoperative examination, data acquisition, guide design, guide fabrication and surgery. Errors may occur at each step, leading to irreversible cumulative effects and thus impacting the accuracy of implant placement. However, clinicians tend to focus on factors causing errors in surgical operations, ignoring the possibility of irreversible errors in nonstandard guided surgery. Based on the clinical practice of domestic experts and research progress at home and abroad, this paper summarizes the sources of errors in guided implant surgery from the perspectives of preoperative inspection, data collection, guide designing and manufacturing and describes strategies to resolve errors so as to gain expert consensus. Consensus recommendation: 1. Preoperative considerations: the appropriate implant guide type should be selected according to the patient's oral condition before surgery, and a retaining screw-assisted support guide should be selected if necessary. 2. Data acquisition should be standardized as much as possible, including beam CT and extraoral scanning. CBCT performed with the patient’s head fixed and with a small field of view is recommended. For patients with metal prostheses inside the mouth, a registration marker guide should be used, and the ambient temperature and light of the external oral scanner should be reasonably controlled. 3. Optimization of computer-aided design: it is recommended to select a handle-guided planting system and a closed metal sleeve and to register images by overlapping markers. Properly designing the retaining screws, extending the support structure of the guide plate and increasing the length of the guide section are methods to feasibly reduce the incidence of surgical errors. 4. Improving computer-aided production: it is also crucial to set the best printing parameters according to different printing technologies and to choose the most appropriate postprocessing procedures.

Regulación de la implantología dental en México / Regulation of dental implantology in Mexico

Introducción: los implantes dentales se han convertido en uno de los tratamientos odontológicos con mayor demanda en todo el mundo, no sólo por el nivel máximo de funcionalidad y de estética, sino también debido a su estabilidad, osteointegración y facilidad en su rehabilitación. Es incierto si los implantes dentales se encuentran normados formalmente en México, lo que motiva a la revisión del estado actual. Objetivo: evidenciar el estado actual de la legislación de la práctica de la implantología dental en México a través de una revisión en la literatura. Material y métodos: revisión de las legislaciones existentes en México para la aplicación de implantes dentales y su contraparte en el mundo a través de la evaluación de normas expedidas en América y Europa. Resultados: se contabilizó un total de 17 escuelas de implantes dentales que cuentan con el reconocimiento de la Secretaría de Educación Pública, de las cuales tres son públicas y 14 privadas. Se presentó una discrepancia en los planes de estudio que va de 16 a 36 meses. Las escuelas no contaron con un aval normativo. Las normas internacionales para control de calidad y aplicación de la tecnología en implantes se ubicaron en Canadá, Estados Unidos, España, Reino Unido y Francia. Conclusiones: contar con un antecedente normativo establecido por los países de primer mundo y ausente en México permite evidenciar la necesidad de implementar una Norma Oficial Mexicana que regule la fabricación, distribución y almacenamiento de los implantes dentales en México. A la vez, la revisión sugiere que la Secretaría de Educación Pública norme los créditos mínimos necesarios en las instituciones educativas reconocidas para la formación de recursos humanos que ejercen la implantología dental (AU)

Introduction: dental implants have become one of the dental treatments with the highest demand in the world, not only because of the highest level of functionality and aesthetics, but also because of their stability, osseointegration and ease of rehabilitation. It is uncertain if dental implants are formally regulated in Mexico, which motivates the review of the current status. Objective: to demonstrate the current state of the legislation for the practice of dental implantology in Mexico through a review of the literature. Material and methods: review of the existing legislation in Mexico, for the application of dental implants and its counterpart in the world, through the evaluation of standards issued in America and Europe. Results: a total of 17 dental implant schools that have the recognition of the Ministry of Public Education were counted, of which 3 are public and 14 private. There was a discrepancy in the study plans that ranged from 16 to 36 months. Schools will not have regulatory backing. The international standards for quality control and application of technology in implants were located in Canada, the United States, Spain, the United Kingdom and France. Conclusions: having a normative antecedent established by the countries of the first world and absent in Mexico, allows to demonstrate the need for the implementation of an Official Mexican Standard, which regulates the manufacture, distribution and storage of dental implants in Mexico. At the same time, the review suggests that the Ministry of Public Education regulate the minimum necessary credits in recognized educational institutions, for the training of human resources that practice dental implantology (AU)

Applications of Hyaluronic Acid (HA) in Dental Implant Treatment: A Systematic Review

@#Introduction: Hyaluronic acid (HA) has a long history and is widely used in cosmetics, medicine, and dermatology. This molecule is still considered relatively new in the field of dentistry. This study aimed to assess the application of HA in dental implant treatment. Method: Search in the multiple indexed databases such as Pubmed, COCHRANE, and Scopus was conducted up until August 2022 using the keywords “hyaluronic acid”, “hyaluronan,” and “dental implant.” Results: The literature search identified 816 articles, and 17 were selected in this study. Three domains of use of HA in dental implant treatment were identified: surface modification of implant surface, treatment after insertion of a dental implant, and bone graft/membrane material. There are eight randomized control trials and nine non-randomized control trials included in this study. Only six studies showed statistically significant results with HA groups. Conclusion: Overall, there are positive findings on the application of HA in dental implant treatment, showing it can be used in dental implantology, with multiple categories of uses.

Low level laser therapy as adjunctive support in implant dentistry: a reliable option? / Terapia láser de baja potencia como apoyo complementario en la implantología: ¿una opción fiable?

Use of low level laser therapy (LLLT) in bone healing has been studied for years, and its application in implant dentistry is still a controversial topic due to the difficult assessment of its clinical efficacy. We report the application of LLLT as aid in the osseointegration in two patients undergone to implant surgery in the upper jaw. In one hemi-arch the LLLT was applied and the other one was used as control. The assessment of the bone area surrounding the fixtures was performed by means of cone beam compute tomography and the area of bone-implants contact was measured by means of InVesalius® software. The radiological findings support the idea of considering the laser biostimulation as an adjunctive aid in implant surgery.

El uso de la terapia con láser de baja potencia (LLLT) en la reparación ósea se ha estudiado durante años y su aplicación en la implantología sigue siendo un tema controvertido, debido a la difícil evaluación de su eficacia clínica. Reportamos la aplicación de LLLT como ayuda en la osteointegración en dos pacientes sometidos a cirugía de implantes en el maxilar superior. En un hemi-arco se aplicó la LLLT y en el otro se utilizó como control. La evaluación del área ósea que rodea a las fijaciones se realizó mediante tomografía computarizada Cone Beam y el área de contacto hueso-implantes se midió mediante el software InVesalius®. Los hallazgos radiológicos apoyan la idea de considerar la bioestimulación con láser como un coadyuvante en la cirugía de implantes.

Comparative analysis of biofilm formation on materials used for the fabrication of implant-supported prostheses

Abstract The purpose of this study was to compare biofilm formation on materials used for the fabrication of implant-supported dental prostheses. Twenty discs (D=15 mm, H=3 mm) were fabricated from one of the following restorative materials: yttria tetragonal zirconia polycrystal (Y-TZP); commercially pure titanium (CP-Ti); or heat-cured polymethyl methacrylate (PMMA). Specimens were polished following standard protocols. A non-contact profilometer (NPFLEX, Bruker, UK) was used to assess the surface roughness of each disk; results were reported as Ra (µm). Five strains of Gram-negative bacteria frequently associated with peri-implantitis, Aggregatibacter actinomycetemcomitans, Candida. albicans, Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia, were cultured on hand-polished discs fabricated from heat-cured PMMA, Y-TZP, or CP-Ti to compare biofilm formation on each type of material. The results were reported as colony-forming units per milliliter (CFU/mL). One-way ANOVA and post hoc tests were used to compare surface roughness and bacterial colonization on the respective materials. Statistical significance was set at a = 0.05. Discs fabricated from Y-TZP had a significantly higher Ra value (350 ± 30 µm) than either PMMA, or CP-Ti discs. Discs fabricated from either Y-TZP and CP-Ti may exhibit less colonization by bacteria associated with peri-mucositis and peri-implantitis. Y-TZP and CP-Ti are suggested materials for fabrication of implant-supported prostheses, considering biofilm formation.

Resumo O objetivo deste estudo foi comparar a formação de biofilme em materiais utilizados na confecção de próteses dentárias implantossuportadas. Vinte discos (D = 15 mm, H = 3 mm) foram confeccionados com um dos seguintes materiais restauradores: zircônia tetragonal policristalina estabilizada por ítrio (Y-TZP); titânio comercialmente puro (CP-Ti); ou polimetilmetacrilato (PMMA). As amostras foram polidas seguindo protocolos padrão. Um perfilômetro sem contato (NPFLEX, Bruker, UK) foi usado para avaliar a rugosidade da superfície de cada disco; os resultados foram relatados como Ra (µm). Cinco cepas de bactérias Gram-negativas freqüentemente associadas a peri-implantite, Aggregatibacter actinomycetemcomitans, Candida. albicans, Porphyromonas gingivalis, Prevotella intermedia e Tannerella forsythia, foram cultivadas em discos polidos à mão feitos de PMMA, Y-TZP ou CP-Ti para comparar a formação de biofilme em cada tipo de material. Os resultados foram relatados como unidades formadoras de colônias por mililitro (UFC/mL). Análise de variância a um fator e testes post hoc foram usados ​​para comparar a rugosidade da superfície e a colonização bacteriana nos respectivos materiais. A significância estatística foi estabelecida em a=0,05. Os discos feitos de Y-TZP tiveram um valor Ra significativamente mais alto (350 ± 30 µm) do que os discos de PMMA ou CP-Ti. Os discos fabricados com Y-TZP e CP-Ti podem apresentar menor colonização por bactérias associadas à perimucosite e peri-implantite. Considerando O Y-TZP e CP-Ti são materiais indicados para a confecção de próteses implantossuportadas, considerando a formação de biofilme

Cone Beam Computed Tomography in Prosthodontics

Cone beam computed tomography (CBCT) is called as C-armcomputed tomography, cone beam volume CT, or flat panelCT. It is an imaging technique in the field of dentistry inwhich the X‑rays are divergent, leading to the formation ofcone shaped beam. The system of CBCT has been designedfor imaging primarily the hard tissues of the maxillofacialregion. It contributes to accurate and effective treatmentplanning for the patient. The increasing demand of thistechnology provides the dental clinician with an imagingmodality capable of providing a three‑dimensional viewof the maxillofacial skeleton with least distortion. CBCTprovides a unique imaging option for various treatment needsof a prosthodontist. It can prove to be beneficial in variousaspects of prosthodontic practice i.e. from imaging of thetemporomandibular joint for accurate movement simulation,to denture therapy. CBCT could play an important role inreduction of hectic routine for the clinician. Therefore, theaim of this article is to specify the applications of CBCT in thefield of prosthodontics along with the benefits and limitationsof CBCT.

Influência do número de roscas e da densidade dos blocos de poliuretano na estabilidade primária de implantes do sistema intraoss / The influence of implant thread number and polyurethane block density on primary stability values of the Intraoss implant system

Objetivo: avaliar e comparar a estabilidade primária dos implantes cilíndricos de 3,75 mm x 11 mm Titaoss e Titaoss dupla rosca, do Sistema Intraoss, instalados em blocos de poliuretano com baixa densidade. Material e métodos: foram realizadas 32 cavidades em dois blocos de poliuretano, simulando as densidades de ossos tipo III e IV. As estabilidades dos implantes foram mensuradas por meio do torque de inserção e frequência de ressonância. Resultados: os implantes Titaoss instalados no osso tipo III apresentaram valores de torque de inserção de 43,1 ± 14,87 Ncm, enquanto os valores dos implantes Titaoss dupla rosca foram 46,9 ± 5,3 Ncm. No osso tipo IV, os implantes Titaoss apresentaram valores de 30 ± 0,0 Ncm e os dupla rosca de 29,4 ± 1,77 Ncm. Não houve diferença significante na estabilidade primária entre os grupos dos implantes (p > 0,05) instalados no mesmo tipo de osso. Os implantes Titaoss instalados no osso tipo III apresentaram valores de ISQ de 57,3 ± 4,69, ao passo que os valores para os implantes Titaoss dupla rosca foram 54,9 ± 3,98. No osso tipo IV, os implantes Titaoss apresentaram valores de 48,4 ± 4,07 ISQ e os dupla rosca de 50,8 ± 3,98 ISQ. As estabilidades primárias dos implantes foram maiores no osso tipo III quando comparado ao IV (p < 0,05). Conclusão: os dois desenhos de implantes permitem a obtenção da estabilidade primária para a técnica da carga mediata. No entanto, para submeter esses tipos de implante à carga imediata, indica-se a técnica da subfresagem.

Objectives: this in vitro study aimed to evaluate and compare the primary stability of the cylindrical implants (3.75 mm x 11 mm) Titaoss and Titaoss double thread from Titaoss System placed in cavities made of low-density polyurethane blocks. Material and methods: 32 cavities were made in two types of polyurethane blocks simulating the type III and IV bone densities. The implant stability values were measured using the final insertion torque and resonance frequency analysis. Results: the Titaoss implants placed in type III bone achieved 43.1 ± 14.87 Ncm, while the double-thread values were 46.9 ± 5.3 Ncm. For bone type IV, the Titaoss implants reached 30Ncm and the double thread 29.4± 1.77 Ncm. No statistically significant differences on implant stability were seen for both groups (p > 0.05) for the same bone type. the Titaoss implants in bone type III had 57.3 ± 4.69 and the double thread 54.9 ± 3.98 ISQ values. In type IV bone, Titaoss reached 48.4 ± 4.07 and the double thread 50.8 ± 3.98 ISQ units. The primary stability values were greater at type III than type IV bone (p < 0.05). Conclusion: both implant designs allow for primary stability. However, the use of an underpreparation technique is recommended in cases of immediate loading protocols.

Histological characterization of sacco's concentrated growth factors membrane / Caracterización histológica de la membrana de los factores de crecimiento concentrados sacco

Along with the emerging needs of the dental patients, numerous techniques for oral tissue stimulation and regeneration were developed to be employed in the modern implant rehabilitation therapies. The Concentrated Growth Factors (CGF) are a relatively new therapeutic presidium that can be used for this purpose, enhancing the regenerative potential property of blood cells. Although literature presents numerous studies evaluating the CGF for their clinical uses and efficacy, data regarding their biological characteristics are very few. The present study evaluates and describes the CGF structural morphology by means of classical histological methods, using haematoxilin-eosin and azan mallory stains. A three layers organization with a fibrin complex network was noted, with blood corpuscular elements entrapped, especially in the most external layer. These descriptions enrich the knowledge about this new type of membrane, showing the bio-morphological side of the regenerative techniques. These findings will be useful in clinical practice for the choice of the most suitable technique in each implant rehabilitation.

Junto con las nuevas necesidades dentales de los pacientes, se han desarrollado numerosas técnicas para la estimulación y regeneración de los tejidos orales para ser empleadas en las modernas terapias de rehabilitación de implante. Los Factores de Crecimiento Concentrados (FCC) son relativamente una nueva alternativa terapéutica que pueden utilizarse para este propósito, mejorando la propiedad regenerativa potencial de las células de la sangre. A pesar de que la literatura presenta numerosos estudios que evalúan los FCC por sus usos clínicos y su eficacia, los datos relativos a sus características biológicas son muy escasos. El presente estudio evalúa y describe la morfología estructural de los FCC por medio de métodos histológicos tradicionales, utilizando hematoxilina-eosina y tinción de Azan Mallory. Se observó una organización en tres capas con una compleja red de fibrina, con elementos corpusculares de la sangre atrapados, especialmente en la capa más externa. Estas descripciones enriquecen el conocimiento acerca de este nuevo tipo de membrana, que muestra el lado biomorfológico de las técnicas regenerativas. Estos resultados serán de utilidad en la práctica clínica para la elección de la técnica más adecuada en los casos de rehabilitación con implantes.

Accuracy of computer-guided implant placement and influencing factors / 华西口腔医学杂志

Digital technology is a new trend in implant dentistry and oral medical technology. Stereolithographic surgical guides, which are computer-guided implant placement, have been introduced gradually to the market. Surgeons are attracted to this approach because of it features visualized preoperative planning, simple surgical procedure, flapless implant, and immediate restoration. However, surgeons are concerned about the accuracy and complications of this approach. This review aims to introduce the classification of computer-guided implant placement. The advantages, disadvantages, and accuracy of this approach are also analyzed. Moreover, factors that may affect the outcomes of computer-guided implant placement are determined. Results will provide a reference to surgeons regarding the clinical application of this approach.

Definitive Presurgical CAD/CAM-Guided Implant-Supported Crown in an Esthetic Area

This paper describes the digital workflow from cone beam computer tomography (CBCT) to the installation of a definitive presurgical zirconium individual crown in a 19-year-old woman requiring implant replacement of a maxillary right lateral incisor. The patient had agenesis of this tooth and had completed the orthodontic treatment. CBCT was conducted and diagnostic casts were digitized. Virtual planning was completed by defining a prosthetically driven implant and a stereolithographic surgical template was produced. Good adaptation of a stereolithographic surgical template was verified in the working cast. Implant and abutment were installed in this cast using a stereolithographic surgical template, and a CAD/CAM definitive zirconium crown was produced. Flapless computer-guided implant surgery was performed. The abutment was connected, and a definitive zirconium crown was cemented using resin cement. The digital workflow presented herein shows high accuracy for a virtually planned implant with flapless guided placement, allowing the successful delivery of a definitive presurgical zirconium single crown in an esthetic area in a single visit. The patient was revaluated after 1 year of function with an excellent outcome of the treatment.

Resumo Este relato descreve o fluxo de trabalho digital desde tomografia de feixes cônicos até a instalação de uma coroa unitária pré cirúrgica definitiva em zircônia em uma mulher de 19 anos que necessitava de reabilitação com implante do incisivo lateral superior direito. A paciente apresentava agenesia deste dente e tinha finalizado o tratamento ortodôntico. Foi realizada a tomografia e os modelos diagnósticos foram digitalizados. O planejamento virtual do implante foi definido pelo planejamento protético virtual e em seguida um guia cirúrgico foi produzido pelo método da esteriolitografia. Foi verificada a boa adaptação deste guia cirúrgico sobre o modelo de trabalho. O implante e o pilar foram instalados neste modelo de trabalho usando o guia cirúrgico e confeccionada coroa pré cirúrgica definitiva em zircônia pela técnica de CAD / CAM. A cirurgia guiada de instalação do implante foi realizada sem deslocamento de retalho. O pilar selecionado foi instalado e coroa pré cirúrgica definitiva em zircônia foi cimentada com cimento resinoso. O fluxo de trabalho digital apresentado mostrou grande precisão para instalação guiada do implante em uma área estética, permitindo a instalação de uma coroa pré cirúrgica definitiva em zircônia em uma única sessão clínica. A paciente foi reavaliada e apresentou excelentes resultados do tratamento após um ano em função.

Tratamento de defeitos alveolares verticais pela técnica de distração osteogênica / Treatment of vertical alveolar defects by means of osteogenic distraction technique

Introdução: a reconstrução alveolar de defeitos ósseos verticais ainda constitui um desafio dentro da Implantodontia. Dentre as diversas técnicas empregadas para a correção de tais defeitos, está a distração osteogênica, a qual tem sido descrita como uma técnica empregada para ganho de tecido ósseo e tecidos moles, sobretudo em cirurgias para reconstrução de rebordos alveolares mandibulares e maxilares, com a finalidade de permitir a instalação de implantes osseointegrados bem posicionados e com maior previsibilidade de sucesso quando submetidos a cargas funcionais. Objetivo: o propósito desse estudo foi avaliar a efetividade do procedimento em dois pacientes tratados pela técnica de distração osteogênica alveolar Relato de caso: os casos clínicos foram avaliados quanto ao ganho ósseo através de exame clínico e radiográfico, pré e pós-distração. Resultados: em ambos os casos, constatou-se, ao final do tratamento, ganho ósseo suficiente para posterior reabilitação com implantes. Conclusão: o sucesso relatado na literatura e nos casos apresentados comprova a eficiência da técnica e sua viabilidade clínica.

Introduction: Alveolar reconstruction of vertical bone defects remains a daunting challenge in implant dentistry. Among the various techniques used to correct such defects is distraction osteogenesis (DO), which has been described as a technique used to gain bone and soft tissues, especially in surgeries for reconstruction of mandibular and maxillary alveolar ridges to allow the placement of dental implants in a favorable position and with greater success predictability when subjected to functional loads. Objective: The purpose of this studywas to evaluate the effectiveness of DO in two patients treated with the technique of alveolar distraction osteogenesis. Case report: The clinical cases were evaluated for bone gain through clinical and radiographic examination, pre- and post-distraction. Results: At the end of treatment, both cases had gained sufficient bone as to enable subsequent rehabilitation with implants. Conclusions: The success rate reported in the literature and in the cases presented here prove the efficiency of the technique and its clinical feasibility.

The current status of laser applications in prosthodontics.

Lasers were introduced into the field of clinical dentistry with the hope of overcoming some of the drawbacks posed by the conventional methods of dental procedures. Since its first experiment for dental application in the 1960s, the use of laser has increased rapidly in the last couple of decades. At present, wide varieties of procedures are carried out using lasers. The aim of this review is to describe the current and emerging applications for lasers in prosthetic dentistry. Used in conjunction with or as a replacement for traditional methods, it is observed that specific laser technologies are becoming an essential component of contemporary dental practice over a decade.

Regeneração óssea de defeitos circunferenciais criados cirurgicamente ao redor de implantes submersos: estudo experimental em cães / Bone healing pattern in surgically created circumferential defects around submerged implants: an experimental study in the dog

Objetivo: descrever o processo de reparo em defeitos marginais ao redor de implantes submersos 1mm abaixo ou acima da crista óssea. Estudo experimental em cães. Material e Métodos: Em 12 cães labradores, todos os pré-molares inferiores e primeiros molares foram extraídos bilateralmente. Três meses após as extrações, foi realizada a incisão sobre o rebordo e o descolamento dos retalhos de espessura total do lado direito da mandíbula. Foram preparados dois sítios cirúrgicos para instalação de implantes, com a região marginal alargada em 5mm de diâmetro para obtenção de um gap de 0,5 mm na região mesial (defeito pequeno) e um gap de 1,25 mm na região distal (defeito grande). Os parafusos de cobertura foram colocados aos implantes e os retalhos suturados para permitir um processo de cicatrização totalmente submerso. Posteriormente, foram realizados os mesmos procedimentos experimentais no lado esquerdo da mandíbula. O momento da realização dessas cirurgias e as eutanásias foram planejados de forma a se obter biópsias com 5, 10, 20, 30 dias de pósoperatórios. Após a eutanásia, os cortes histológicos foram processados laboratorialmente para análise histomorfométrica. Resultados: Aos 30 dias pós-operatório, os defeitos ósseos apresentaram-se parcialmente preenchidos por osso neoformado em todos os espécimes. A formação óssea ocorreu originando-se a partir da base do defeito e das paredes laterais. Um maior volume de osso neoformado foi observado nos defeitos grandes quando comparado aos pequenos. A maior parte de osso neoformado nos defeitos grandes formou-se entre o décimo e vigésimo dias de pós-operatórios. Entretanto, o contorno do osso neoformado localizou-se a uma distância similar da superfície do implante (aproximadamente 0,4 mm) em ambos os tipos de defeitos, no período de 30 dias. Nos defeitos grandes foi observado uma menor quantidade de osso neoformado em contato com o implante, originado da base dos defeitos (cerca de 0,8 mm), quando comparado aos...

Objective: to describe the healing of marginal defects below or above one millimeter of dimension around submerged implants in a dog model. Material and Methods: In 12 Labrador dogs, all mandibular premolars and first molars were extracted bilaterally. After 3 months of healing, full-thickness flaps were elevated in the edentulous region of the right side of the mandible. Two recipient sites were prepared and the marginal 5 mm were widened to such an extent to obtain, after implant installation, a marginal gap of 0.5 mm at the mesial site (small defect) and of 1.25 mm at the distal site (large defect). Titanium healing caps were affixed to the implants and the flaps were sutured allowing a fully-submerged healing. The experimental procedures were subsequently performed in the left side of the mandible. The timing of the experiments and sacrifices were planned in such a way to obtain biopsies representing the healing after 5, 10, 20, 30 days. Ground sections were prepared and histomorphometrically analyzed. Results: The filling of the defect with newly formed bone was incomplete after one month of healing in all specimens. Bone formation occurred from the base and the lateral walls of the defects. A larger volume of new bone was formed in the large compared to the small defects. Most of the new bone at the large defect was formed between the 10 and the 20-day period of healing. After one month of healing, the outline of the newly formed bone was, however, located at a similar distance from the implant surface (about 0.4 mm) at both defect types. Only minor newly formed bone in contact with the implant, starting from the base of the defects, was seen at the large defects (about 0.8 mm) while a larger amount was detected at the small defects (about 2.2 mm). Conclusion: Marginal defects around titanium implants appeared to regenerate in 20-30 days by means of a distance osteogenesis. The bone fill of the defects was, however, incomplete after one months

Regeneração óssea de defeitos circunferenciais criados cirurgicamente ao redor de implantes submersos: estudo experimental em cães / Bone healing pattern in surgically created circumferential defects around submerged implants: an experimental study in the dog

Objetivo: descrever o processo de reparo em defeitos marginais ao redor de implantes submersos 1mm abaixo ou acima da crista óssea. Estudo experimental em cães. Material e Métodos: Em 12 cães labradores, todos os pré-molares inferiores e primeiros molares foram extraídos bilateralmente. Três meses após as extrações, foi realizada a incisão sobre o rebordo e o descolamento dos retalhos de espessura total do lado direito da mandíbula. Foram preparados dois sítios cirúrgicos para instalação de implantes, com a região marginal alargada em 5mm de diâmetro para obtenção de um gap de 0,5 mm na região mesial (defeito pequeno) e um gap de 1,25 mm na região distal (defeito grande). Os parafusos de cobertura foram colocados aos implantes e os retalhos suturados para permitir um processo de cicatrização totalmente submerso. Posteriormente, foram realizados os mesmos procedimentos experimentais no lado esquerdo da mandíbula. O momento da realização dessas cirurgias e as eutanásias foram planejados de forma a se obter biópsias com 5, 10, 20, 30 dias de pósoperatórios. Após a eutanásia, os cortes histológicos foram processados laboratorialmente para análise histomorfométrica. Resultados: Aos 30 dias pós-operatório, os defeitos ósseos apresentaram-se parcialmente preenchidos por osso neoformado em todos os espécimes. A formação óssea ocorreu originando-se a partir da base do defeito e das paredes laterais. Um maior volume de osso neoformado foi observado nos defeitos grandes quando comparado aos pequenos. A maior parte de osso neoformado nos defeitos grandes formou-se entre o décimo e vigésimo dias de pós-operatórios. Entretanto, o contorno do osso neoformado localizou-se a uma distância similar da superfície do implante (aproximadamente 0,4 mm) em ambos os tipos de defeitos, no período de 30 dias. Nos defeitos grandes foi observado uma menor quantidade de osso neoformado em contato com o implante, originado da base dos defeitos (cerca de 0,8 mm), quando comparado aos...

Objective: to describe the healing of marginal defects below or above one millimeter of dimension around submerged implants in a dog model. Material and Methods: In 12 Labrador dogs, all mandibular premolars and first molars were extracted bilaterally. After 3 months of healing, full-thickness flaps were elevated in the edentulous region of the right side of the mandible. Two recipient sites were prepared and the marginal 5 mm were widened to such an extent to obtain, after implant installation, a marginal gap of 0.5 mm at the mesial site (small defect) and of 1.25 mm at the distal site (large defect). Titanium healing caps were affixed to the implants and the flaps were sutured allowing a fully-submerged healing. The experimental procedures were subsequently performed in the left side of the mandible. The timing of the experiments and sacrifices were planned in such a way to obtain biopsies representing the healing after 5, 10, 20, 30 days. Ground sections were prepared and histomorphometrically analyzed. Results: The filling of the defect with newly formed bone was incomplete after one month of healing in all specimens. Bone formation occurred from the base and the lateral walls of the defects. A larger volume of new bone was formed in the large compared to the small defects. Most of the new bone at the large defect was formed between the 10 and the 20-day period of healing. After one month of healing, the outline of the newly formed bone was, however, located at a similar distance from the implant surface (about 0.4 mm) at both defect types. Only minor newly formed bone in contact with the implant, starting from the base of the defects, was seen at the large defects (about 0.8 mm) while a larger amount was detected at the small defects (about 2.2 mm). Conclusion: Marginal defects around titanium implants appeared to regenerate in 20-30 days by means of a distance osteogenesis. The bone fill of the defects was, however, incomplete after one months

Análise de critérios de sucesso em endodontia e implantodontia / Analysis of criteria of success in endodontics and implant dentistry

Objetivo: Avaliou-se em estudos longitudinais os critérios de sucesso em endodontia e implantodontia. Material e métodos: Fontes de catalogação bibliográfca identifcadas eletronicamente pela MEDLINE e Cochrane Collaboration foram utilizadas. A estratégia de busca na base de dados MEDLINE foi realizada pelo portal PubMed(htp://www.ncbi.nlm.nih.gov/PubMed), de 1966 até 19 de janeiro de 2009, a partir de várias combinações de palavras-chave: success criteria and dental implants OR failure criteria and dental implants OR success criteria and osseointegration OR failure criteria and osseointegration OR success criteria and endodontic treatment OR failure criteria and endodontic treatment OR success criteria and root canal treatment OR failure criteria and root canal treatment OR success criteria and endodontic therapy OR failure criteria and endodontic therapy OR success criteria and endodontics OR failure criteria and endodontics. Resultados: A busca apresentou 684 artigos, sendo que destes, 263 não vinculavam-se com o objetivo, 206 eram revisões de literatura, 378 relacionavam-se com estudos em humanos, 14 estudos em animais, e 112 incluíram estudos in vitro. Dos 378 estudos em humanos, 15 satisfizeram os critérios de inclusão, sendo que todos estavam relacionados ao sucesso e/ou sobrevivência de implantes, não havendo trabalho relacionado ao sucesso do tratamento endodôntico não-cirúrgico. Foi analisado o sucesso de 1601 implantes com índice de sucesso médio de 90,84%; a sobrevivência média de 5663 implantes foi de 94,7%. Conclusão: Os estudos adotaram critérios de sucesso distintos para ambas as áreas, o que implica na necessidade do estabelecimento de um modelo de referência contemporâneo e de consenso, com vistas a facilitar os futuros estudos.

Objective: The criteria of success in endodontics and implant dentistry were evaluated in longitudinal studies. Material and methods: Bibliographic catalogue sources, electronically identifed as MEDLINE (htp://www.ncbi.nlm.nih.gov/PubMed), from 1966 until January 19th, 2009, and Cochrane Library were used. On the searching strategy, the following combination of keywords were used: success criteria and dental implants OR failure criteria and dental implants OR success criteria and osseointegration OR failure criteria and osseointegration OR success criteria and endodontic treatment OR failure criteria and endodontic treatment OR success criteria and root canal treatment OR failure criteria and root canal treatment OR success criteria and endodontic therapy OR failure criteria and endodontic therapy OR success criteria and endodontics OR failure criteria and endodontics. Results: The search presented 684 related articles, 263 articles that had no relation with the objective of this study, 206 were literature reviews, 378 were related with in vivo studies on humans, 14 studies on animals, and 112 were in vitro studies. From the 378 studies on humans, 15 satisfed the inclusion criteria, and all these were related to the success and/or survival of dental implants, with no work related to the success of non-surgical root canal treatment. It was analyzed the success of 1601 implants with average success rate of 90.84%; the average survival of 5663 implants was 94.7%. Conclusion: It was observed that the investigations used distinct success criteria for the root canal treatments and the dental implants, what implicates the need of adoption of a consensus and actual model, to facilitate the future studies.

Evaluation of pre-tightening in abutments and prosthetic screws on different implant connections / Avaliação do pré-aparafusamento em pilares e parafusos protéticos em diferentes conexões de implante

Purpose: This study evaluated pre-tightening maintenance in abutment and prosthetic screwsof external and internal hexagon implant with straight and angled abutments. Methods: Four groups of implants and abutments were assessed combining internal andexternal hexagon and straight and angled abutments, which were retained by titanium screws tightened to 20 N.cm. Crowns were retained with gold screws tightened at 10 N.cm. A verticalline was ascribed across the implant-abutment-crown interface to verify horizontal displacement by a light microscope. The fatigue tests were performed in a servo-hydraulic machine, which delivered forces between 100 and 120 N for 250,000 cycles. The screw was removed, and the detorque value was recorded. Data were analyzed with 2-way ANOVA and Tukey's test. Results: No horizontal displacement was observed on the interface of implant-abutment or abutment and crown. It was found significant difference for prosthetic screw between implant connection types, but without interaction with abutment. However, for abutment screw, there was a difference between implant connection types and abutment with interaction between implant and abutments. The straight abutment showed significant better performance than the 17º angled abutment. Conclusion: The connection implant types or abutment affected pre-tightening maintenance. Internal and external hexed connections were effective to avoid horizontal displacement of crowns.

Objetivo: Este estudo avaliou a manutenção do pré-aparafusamento em pilar e parafuso protético de implantes com hexágono interno e externo, com pilares retos e angulados. Metodologia: Quatro grupos de implantes e pilares foram avaliados, combinando-se ohexágono interno ou externo e o pilar reto ou angulado, os quais foram retidos por parafusos de titânio aparafusados 20 N.cm. As coroas fora retidas com parafusos de ouro aparafusadosa 10 N.cm. Uma linha vertical foi delineada sobre a interface implante-pilar-coroa para verificar o deslocamento vertical com uso de microscópio ótico. Os testes de fadiga foram realizados em uma máquina servo-hidráulica, que promoveu forças entre 100 e 120 N por 250.000 ciclos. O parafuso foi removido e o valor de detorque for registrado. Os dadosforam analisados por ANOVA de dois fatores e teste de Tukey. Resultados: Nenhum deslocamento horizontal foi observado na interface implante-pilar oupilar-coroa. Observou-se uma diferença significativa para o parafuso protético entre os tipos de conexão do implante, mas sem interação com o pilar. Porém, para o parafuso do pilar houve diferença entre tipos de conexão e pilar, com interação entre pilar e implante. O pilar reto mostrou melhor performance que o pilar angulado a 17°. Conclusão: Os tipos de conexão do implante ou pilar afetaram a manutenção do pré aparafusamento. As conexões de hexágono interno e externo foram efetivas para evitar o deslocamento horizontal das coroas.

Tissue Engineering with rhBMP-2: Bone Reconstruction in Implant Dentistry / 대한치주과학회지

The preclinical and clinical studies reviewed herein show that rhBMP-2 induces normal physiologic bone in relevant defects in the craniofacial skeleton. The newly formed bone assumes characteristics of the adjacent resident bone, and allows placement and osseointegration of dental implants. Clearly, the bone inducing capacity of rhBMP-2 is carrier and site dependent. rhBMP-2 in an absorbable collagen sponge carrier induces relevant bone formation in space providing defects. Space providing carries extends this possibility to nonspace providing sites. Notably, some ceramic and polymeric biomaterials may substantially interfere with rhBMP-2 induced osteogenesis.