Influência do material oclusal na distribuição de tensões em próteses implantossuportadas unitárias

Objective: the aim of this study was to evaluate the influence of occlusal veneering material in single fixed implant-supported crowns through the 3-D finite element method. Material and methods: Four models were fabricated using the Rhinoceros 4.0, SolidWorks, and InVesalius softwares. Each model represented a block of mandibular bone with an external hexagon implant of 5 mm x 10 mm and different veneering materials including NiCr (1), porcelain (2), composite resin (3), and acrylic resin (4). An axial load of 200 N and an oblique load of 100 N were applied. Results: model (2) with porcelain veneering presented a lower stress concentration for the NiCr framework, followed by the composite resin and acrylic resin. The stress distribution to the implant and bone tissue was similar for all models. Conclusions: there is no difference of stress distribution to the implant and supporting structures by varying the veneering material of a single implant-supported prosthesis.

Reabilitação estética com enfoque nas diferentes cores de substratos e na escolha da cor do cimento adesivo

The evolution of techniques and materials applied to adhesive ceramic restorations resulted in the intensification of its use, proving to be an excellent method of aesthetic restoration. Some important features of this technique are its conservative preparation, which avoids an excessive loss of tooth structure and its high aesthetic value provided by the ceramic even when utilized under different color of dental substrates. The aim of this paper was to report a clinical case with full crowns, porcelain veneers and non-prep veneers, enhancing peculiarities related to the material used, tooth preparation techniques, cementing, indications and contraindications.

Wettability behavior of nanotubular TiO2 intended for biomedical applications

Nanotubes have been subject of studies with regard to their ability to promote differentiation of several cells lines. Nanotubes have been used to increase the roughness of the implant surfaces and to improve bone tissue integration on dental implant. In this study TiO2 nanotube layer prepared by anodic oxidation was evaluated. Nanotube formation was carried out using Glycerol-H2O DI(50-50 v/v)+NH4F(0,5 a 1,5% and 10-30V) for 1-3 hours at 37ºC. After nanostructure formation the topography of surface was observed using field-emission-scanning-microscope (FE-SEM). Contact angle was evaluated on the anodized and non-anodized surfaces using a water contact angle goniometer in sessile drop mode with 5 μL drops. In the case of nanotube formation and no treatment surface were presented 39,1° and 75,9°, respectively. The contact angle describing the wettability of the surface is enhanced, more hydrophilic, on the nanotube surfaces, which can be advantageous for enhancing protein adsorption and cell adhesion.

Deslocamento de implante dentário para o seio maxilar: relato de caso

The residual alveolar ridges may be unfavorable for implant placement. The edentulous maxilla is often challenging for the oral surgeon because of the lack of bone as a consequence of alveolar ridge resorption and/or maxillary sinus pneumatization. Accidents or complications may occur when some of these issues are not being known. This article reports one case of implant displaced into the maxillary sinus, 27 days after sinus bone augmentation with simultaneous dental implant installation, causing moderated sinusitis symptoms. The implant was removed through oral cavity access to maxillary sinus.

Relation between bruxism and dental implants

OBJECTIVE: The aim of this study was to gather information and discuss the predictability of implant-supported prostheses in patients with bruxism by performing a literature review. METHODS: In order to select the studies included in this review, a detailed search was performed in PubMed and Medline databases, using the following key words: bruxism, dental implants, implant supported prosthesis, and dental restoration failure. Items that were included are: case reports, randomized controlled trials, in vitro studies, literature and systematic reviews, with or without meta-analysis, of the last 20 years that addressed the theme. Articles without abstracts, animal studies, articles in languages other than English and articles from journals unrelated to the dental field were excluded. RESULTS: after analysis according to inclusion and exclusion criteria, 28 articles were selected from a total of 54. It is known from the array of scientific articles which have assessed, either through retrospective, prospective or experimental studies, that the biomechanical and biological impact of bruxism on implant-supported prostheses is small, and that the literature has contributed little to exemplify the prosthetic limits of safety for the specialist from a clinical point of view. CONCLUSION: Although there is still no general consensus on this matter, most of the literature review articles do provide clinical guidelines that contribute to implant supported prostheses longevity and stability in patients with bruxism.

A importância da mucosa queratinizada na implantodontia

The purpose of current implantology is to ensure that implants maintain its state of full health, proper function and aesthetics. The aim of this paper is to discuss, through a literature review, the importance of keratinized mucosa in relation to cleaning, gingival maintenance, aesthetics involving dentistry implant and evaluating some options to provide a keratinized mucosa when it is insufficient. For the studies identification, it is included or considered in this review, Pubmed database with the following keywords: implant and mouth mucosa and, according to the criteria for inclusion and exclusion, 27 articles were selected. According to the reviewed articles, it was found that the keratinized tissue does not influence the survival of the implant, but it facilitates the cleaning, decreases the irritation of the peri-implant tissues and promotes aesthetics in anterior regions.

Parafunção severa: reabilitação oral com prótese total mandibular x overlay maxilar: relato de caso

In many oral rehabilitation professionals seeking venture renew people smile. However, these procedures have functional implications and aesthetic criteria which must be satisfied so that the final result is predictable. The restoration of relations intermaxillary, phonetics, masticatory function, esthetics and patient comfort are the goals to be achieved. An effective way to achieve these goals when immediate reconstruction with permanent dentures is not possible, make use of a type of partial denture called overlay. Bruxism is a manifestation of biopsychological imbalance that affects the stomatognathic system, characterized by clenching and / or attrition of teeth together so centric or eccentric, can be manifestation of nocturnal or diurnal. Its effects can manifest themselves in different parts of the stomatognathic system, varying the severity of the damage as the resistance of the structures affected, the time of existence, its regularity and the general state of the wearer. The description of the steps followed in solving this case, in which the patient edentulous mandibular arch while the maxillary arch showed absence of teeth 16 and 26 and, except for the teeth 17 and 27, all other teeth showed wear very sharp in the sense denoting incisal cervical, severe impairment of the vertical dimension, the quality of masticatory function and a marked impairment phonetic, this case report aims to guide the beginning of a rehabilitation, as well as the transitional phase of treatment for recovery of functional and aesthetic relationships intermaxillary .

Influência do formato do rebordo alveolar sagital em reabilitações com associação de prótese parcial removível de extremidade livre e implante ósseo integrado

The association of mandibular distal extension removable partial dentures with an osteointegrated implant is a treatment option at hasn't been fully explored by modern rehabilitation dentistry yet. The objective of this study is to evaluate, by means of the bidimensional method of finite elements, the distribution of tension on the structures supporting the distal extension removable partial denture (DERPD), associated to a 10.0 x 3.75 mm osteointegrated implant with an ERA retention system, in alveolar ridges of different shapes. Eight models were created, representing, from a sagittal perspective: Model A (MA) – a half arch with a horizontal ridge without posterior support, with the presence of the lower left canine, and a conventional DERPD, with metallic support in the incisal aspect of this canine, as replacement for the first and second pre-molars and the first and second molars of the lower left half arch; Model B (MB) – similar to MA, but different because of the presence of a 3.75 x 10.00 mm implant with an associated ERA retention system in the posterior region of the DERPD base; Model C (MC) - similar to MA, however with a distally ascending ridge format; Model D (MD) – similar to MC, but different because there is an implant associated to a retention system; Model E (ME) - similar to MA, however with a distally descending ridge format; Model F (MF) – similar to ME, but ditfferent in the sense that there is an implant with an associated ERA retention system; Model G (MG) – similar to MA, however with a distally descending-ascending ridge format; Model H (MH) – similar to MG, but different in the sense that there is an implant with an associated ERA retention system. The finite element program ANSYS 9.0 was used to load the models with vertical forces of 50 N, on each cuspid tip. The format of distal descending edge (ME and MF) was that presented worse results, so in the models with conventional RPD as in the models with RPD associated to the implant and ERA system of retention, for the structures gingival mucosa and tooth support. 1) the distally descending ridge presented the most significant stress in the model with the conventional RPD (ME) or with a prosthesis associated to an implant (MF) and 2) the horizontal ridge (MB) provided more relief to the support structures, such as the tooth and the spongy bone, when there was an implant associated to an ERA retention system. The incorporation of the implants with the ERA system retention, in the posterior area of the toothless edge, it promotes larger stability and retention to PPREL, improving the patient's masticatory acting and, consequently, its comfort and function.

The influence of the alveolar ridge shape on the stress distribution in a free-end saddle removable partial denture supported by implant

The alveolar ridge shape plays an important role in predicting the demand on the support tooth and alveolar bone in the removable partial denture (RPD) treatment. However, these data are unclear when the RPD is associated with implants. This study evaluated the influence of the alveolar ridge shape on the stress distribution of a free-end saddle RPD partially supported by implant using 2-dimensioanl finite element analysis (FEA). Four mathematical models (M) of a mandibular hemiarch simulating various alveolar ridge shapes (1-distal desceding, 2- concave, 3-horizontal and 4-distal ascending) were built. Tooth 33 was placed as the abutment. Two RPDs, one supported by tooth and fibromucosa (MB) and other one supported by tooth and implant (MC) were simulated. MA was the control (no RPD). The load (50N) were applied simultaneously on each cusp. Appropriate boundary conditions were assigned on the border of alveolar bone. Ansys 10.0 software was used to calculate the stress fields and the von Mises equivalent stress criteria (σvM) was applied to analyze the results. The distal ascending shape showed the highest σvM for cortical and medullar bone. The alveolar ridge shape had little effect on changing the σvM based on the same prosthesis, mainly around the abutment tooth.

Influencia del nivel de inserción ósea del diente soporte en el desplazamiento de PPR de extremidad libre mandibular asociada al implante oseointegrado

The rehabilitation with mandibular distal extension removable partial dentures (DERPD) is complex and the use of implants has been improving the functioning of this approach. The insertion bony level around of the last support tooth is an aggravating factor, since it can harm the longevity of the treatment. Thus, the aim of this research was to evaluate the displacement tendency of a mandibular DERPD associated to an implant, with different insertion bony levels and different connections between the RPD and the support tooth, by finite element analysis. Eight models were made: MA - DERPD, incisal rest, no bony loss; MB - DERPD, distal plate, no bony loss; MC - DERPD, incisal rest, no bony loss, with implant and ERA system; MD - DERPD, distal plate, no bony loss, with implant and ERA system; ME - DERPD, incisal rest, bony loss; MF - DERPD, distal plate, bony loss; MG - DERPD, incisal rest, bony loss, with implant and ERA system; MH - DERPD, distal plate, bony loss, with implant and ERA system. Loads of 50 N in each peak were applied. Displacement maps were obtained and showed that implant favors this association and the bony loss harms the prognostic of the prosthesis. It is concluded that: the introduction of the implant with ERA system reduced the displacement tendency of the tooth and supporting structures; introduction of distal plate reduced the movement tendency of the support tooth; the decrease of the periodontal support didn't influence significantly the displacement tendency of the models with distal plate distal, but it influenced the models with distal incisal rest.

Humanização na assistência odontológica de pessoas com deficiência, através do projeto Cão Cidadão-Unesp

The Araçatuba School of Dentistry along with the Veterinary Medical Course, both from UNESP, develop the Extension Project called “Cão Cidadão UNESP” (Unesp Citizen Dog), which is accomplished in some assistance societies, including the Dental Assistance Center to Persons with Disabilities (“Centro de Assistência Odontológica à Pessoa com Deficiência” - CAOE-UNESP). This project develops a multidisciplinary work involving professionals and students from health sciences. The project aims at developing activities to relieve stress, fear and anxiety of patients with disabilities in the moment that precedes the dental treatment. The team performs procedures such as walking with the dogs and patients, toothbrushing the dogs so the patients can see it, in order to learn and motivate themselves, dressing the dogs with some accessories such as white clothes, mask and cap, to associate with image of the dentist, making this relationship more pleasant and welcoming. It is evidenced, through reports of professionals, that the patients become calmer and more collaborative with the dentists, distracting them from the treatment focus and creating a positive bond. It should be noted that this experience has contributed to motivate the professionals to introduce new techniques for dental approach, such as Animal Assisted Therapy. It also shows that animals can be very helpful in treating people with disabilities, because they offer a lot of love, companionship and provide moments of joy and happiness to the participants.

Reação de tecido subcutâneo ao cimento Portland modificado (CPM)

Introdução: o objetivo do estudo foi avaliar a resposta do tecido subcutâneo de ratos a implantes de tubos de polietileno com cimento Portland modificado (CPM) (EGEO S.R.L., Buenos Aires, Argentina) comparado com o MTA Angelus® (Angelus, Londrina/PR). Métodos: esses materiais foram colocados em tubos de polietileno e implantados no tecido conjuntivo dorsal de ratos Wistar por 7, 15, 30, 60 e 90 dias. Os espécimes foram preparados e corados com hematoxilina e eosina ou Von Kossa, ou não corados por luz polarizada. Foram realizadas avaliações quantitativas e qualitativas das reações. Resultados: ambos os materiais causaram reações moderadas em 7 dias, decaindo com o tempo. O MTA Angelus causou reações leves em 15 dias, decaindo com o tempo. A resposta foi similar ao controle em 30, 60 e 90 dias com CPM e MTA Angelus. Foram observadas mineralização e granulações birrefringentes à luz polarizada em ambos os materiais. Conclusões: foi possível concluir que o CPM e o MTA Angelus foram biocompatíveis em modelo de rato e estimularam a mineralização.

Giroversão dental: formação de imagem radiográfica virtual

Entre as diversas anomalias dentárias, a giroversão dental constitui uma anomalia de grande prevalência, na qual o dente realiza rotação em torno do seu próprio eixo. No exame radiográfico panorâmico é possível verificar a presença de giroversão, porém, quando a dinâmica de giro do eixo do equipamento não coincide com a curvatura da maxila e mandíbula, a imagem dos dentes apresenta-se girovertida ou com apinhamento dental. O presente trabalho teve por objetivo avaliar se as giroversões dentais presentes nas radiografias panorâmicas são verdadeiras ou apenas “virtuais”. Foram selecionadas 71 radiografias panorâmicas com imagens sugestivas de dentes girovertidos, de pacientes que também possuíam a documentação da cavidade bucal por fotografia e modelo de estudo. A média de idade dos pacientes avaliados foi 15 anos de idade. A imagem radiográfica panorâmica, fotografia e modelo de estudo foram avaliadas por um único examinador. Na avaliação das radiografias panorâmicas foram encontradas 246 dentes girovertidos. Porém, ao avaliar a fotografia e o modelo de estudo destes pacientes comprovou-se apenas 127 dentes com giroversão. Estes resultados indicam uma correspondência clinica/radiográfica de 51,4 %, ou seja, 48,6% das giroversões identificadas radiograficamente, eram “virtuais”. Pode-se concluir que o diagnóstico de giroversão dental utilizando a radiografia panorâmica deve ser confirmado pelo exame clínico para evitar diagnósticos falsos positivos.

Achados incidentais de calcificações em tecidos moles: relato de caso clínico

As ossificações do complexo estilo-hióideo (OCEH), os tonsilólitos e os ateromas são exemplos calcificações em tecidos moles incidentalmente encontrados em exames de imagem. Atualmente com a utilização da tomografia computadorizada de feixe cônico (TCFC) na odontologia, há um aumento do número desses achados. Objetivo: Relatar um caso clínico com calcificações em tecidos moles e comparar esses achados entre a radiografia panorâmica e a TCFC do mesmo paciente. Paciente masculino, 77 anos, compareceu a Clínica de Radiologia para realizar radiografia panorâmica e TCFC para planejamento de implantes. Na radiografia panorâmica pode-se observar a OCEH bilateral e presença de uma área radiopaca localizada no ramo ascendente da mandíbula, que foi compatível com esclerose óssea. Na análise da TCFC constatou a presença da OCEH bilateralmente. Porém a área radiopaca primeiramente sugestiva de esclerose óssea, na TCFC foi sugerida como tonsilólito, pois não estava localizada no ramo ascendente da mandíbula, e sim nos tecidos moles da região próxima aos espaços aéreos. No exame de TCFC foi possível a visualização de outra estrutura calcificada do lado direito do paciente, na altura da vértebra C4, heterogênea que foi compatível com ateroma. O diagnóstico das calcificações pode não ser preciso quando se utiliza apenas a radiografia panorâmica, além da possibilidade de apresentar falso negativo, como no caso do ateroma. Assim sendo quando o paciente possuir o exame de TCFC esse deve ser completamente avaliado, para que sejam diagnosticadas as possíveis calcificações em tecidos moles presentes.

Necessidades de tratamento odontológico entre nativos brasileiros da reserva indígena Umutina, Estado do Mato Grosso

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)