Is the Fixed Mandibular 3-Implant Retained Prosthesis Safe and Predicable for Full-Arch Mandibular Prostheses? A Systematic Review.

PURPOSE: To evaluate implant and prosthetic survival rates of full-arch rehabilitations retained by three implants in patients with edentulous mandibles. MATERIALS AND METHODS: This systematic review was developed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The focused question was: Are fixed mandibular 3-implant retained prostheses safe and predicable for full-arch mandibular prostheses? The Medline/PubMed and Cochrane Library databases were used to conduct the systematic search for clinical trials on fixed mandibular 3-implant retained prostheses published between 1999 and 2020. Only English-language studies that presented information on implant and prosthetic survival were included. RESULTS: A total of 302 studies were identified, of which 13 addressed the inclusion criteria. Additionally, 574 participants were included in these studies. As reported, 73 (4.57%) of 1596 implants failed, with a survival rate of 95.43%. In addition, the mean survival rate of the presented prostheses was 89.66%. The mean marginal bone loss was 1.09 mm. CONCLUSION: Within the limitations of the present review, implant and prosthetic survival rates of fixed mandibular 3-implant retained prostheses were similar to those of full-arch mandibular prostheses retained by four or more implants. Further research exploring the topic is necessary.

Assessment of nose protector for sport activities: finite element analysis.

There has been a significant increase in the number of facial fractures stemming from sport activities in recent years, with the nasal bone one of the most affected structures. Researchers recommend the use of a nose protector, but there is no standardization regarding the material employed. Clinical experience has demonstrated that a combination of a flexible and rigid layer of ethylene vinyl acetate (EVA) offers both comfort and safety to practitioners of sports. The aim of the present study was the investigation into the stresses generated by the impact of a rigid body on the nasal bone on models with and without an EVA protector. For such, finite element analysis was employed. A craniofacial model was constructed from images obtained through computed tomography. The nose protector was modeled with two layers of EVA (1 mm of rigid EVA over 2 mm of flexible EVA), following the geometry of the soft tissue. Finite element analysis was performed using the LS Dyna program. The bone and rigid EVA were represented as elastic linear material, whereas the soft tissues and flexible EVA were represented as hyperelastic material. The impact from a rigid sphere on the frontal region of the face was simulated with a constant velocity of 20 m s(-1) for 9.1 µs. The model without the protector served as the control. The distribution of maximal stress of the facial bones was recorded. The maximal stress on the nasal bone surpassed the breaking limit of 0.13-0.34 MPa on the model without a protector, while remaining below this limit on the model with the protector. Thus, the nose protector made from both flexible and rigid EVA proved effective at protecting the nasal bones under high-impact conditions.

Prevalence of malocclusions in the 13-20-year-old categories of football athletes.

The dentist can offer athletes improvement in their physical performance through the maintenance of oral health, preventing and treating any and all changes in the stomatognathic system, such as dental malocclusions, that compromise the athletes' performance. The objective of this study is to research the presence of dental malocclusions in athletes of the category between 13 and 20 years of age, from the São Paulo Football Club. 84 athletes participated in this study, dealing with the following topics: molar relation (Angle's classification); presence of overbite; underbite; overcrowding; abnormal spacing; open bite; and anterior, posterior, bilateral and unilateral crossbite; midline deviation and facial type (mesofacial, brachyfacial and dolichofacial). Only one table was made, showing percentages. In regard to Angle's molar relation, 89% are in Class I, 8% in Class II, 3% Class III, 9% of the athletes had overbite, 4% had underbite, 13% had overcrowding and 21% had abnormal spacing. In regard to the bite, 11% presented anterior open bite. In regard to crossbite, 7% presented unilateral crossbite on the right side and 2% on the left side; 5% presented posterior crossbite and 4% anterior crossbite. In regard to midline deviations, 4% presented deviation in the maxilla and 33% in the mandible. In regard to facial type: 39% are dolichofacial, 4% brachyfacial and 57% mesofacial. Based on the results shown, proposals for the implementation of dental, phoniatric, and Ear, Nose and Throat (ENT) practices are already being discussed with the multidisciplinary team of the club involved.

Candida albicans in patients with oronasal communication and obturator prostheses.

Patients using obturator prostheses often present denture-induced stomatitis. In order to detect the presence of oral Candida albicans in patients with oronasal communications and to evaluate the effectiveness of a topical antifungal treatment, cytological smears obtained from the buccal and palatal mucosa of 10 adult patients, and from the nasal acrylic surface of their obturator prostheses were examined. A therapeutic protocol comprising the use of oral nystatin (Mycostatin) and prosthesis disinfection with sodium hypochlorite was prescribed for all patients. Seven patients were positive for C. albicans in the mucosa, with 1 negative result for the prosthetic surface in this group of patients. Post-treatment evaluation revealed the absence of C. albicans on prosthesis surface and on the oral mucosa of all patients. The severity of the candidal infection was significantly higher in the palatal mucosa than in the buccal mucosa, but similar in the palatal mucosa and prosthesis surface, indicating that the mucosa underlying the prosthesis is more susceptible to infection. The therapeutic protocol was effective in all cases, which emphasizes the need for denture disinfection in order to avoid reinfection of the mucosa.

Uso de íris digitalizada na reabilitação protética ocular / Use of digital iris in ocular prosthetic rehabilitation

Introdução: um dos fatores imprescindíveis no resultado estético satisfatório do tratamento reabilitador protético ocular é a reprodução fiel da íris do olho remanescente na íris protética. Trata-se da dissimulação da perda para os pacientes afetados. Objetivo: este trabalho apresenta uma nova técnica de confecção da íris protética, utilizando imagem fotográfica digitalizada da íris remanescente, em adesivo. Métodos: em razão da fotodegradação que compromete a longevidade das próteses oculares, decidiu-se avaliar a estabilidade das cores, da técnica proposta, por meio de teste de envelhecimento acelerado. Para os ensaios, foram confeccionados corpos de prova simulando a íris protética, reproduzida em adesivo, nas cores verde, azul, marrom e preto. A variação do grau de degradação foi avaliada mediante leitura colorimétrica inicial e após, em três intervalos semanais, durante o envelhecimento artificial com radiação ultravioleta. Resultados: a análise estatística sugere que, quando as cores foram avaliadas em função do período de ensaio de envelhecimento artificial, somente na cor azul houve diferença estatisticamente significativa. Conclusões: nenhuma das cores apresentou uma degradação de cor acima do nível clinicamente aceitável, resultado bastante favorável para a viabilidade da técnica proposta.

Evaluation of iris color stability in ocular prosthesis.

UNLABELLED: Accurate iris reproduction in the fabrication of ocular prosthesis in order to match the remaining eye is a key factor to mask the loss and achieve an esthetic outcome for anophthalmic patients. This study evaluated the stability of acrylic paints used for replicating iris color in ocular prostheses by the analysis of two factors: the temperature of the acrylic resin polymerization cycle during prosthesis fabrication and the incidence of sun light, which is the main photodegrading agent undermining the longevity of ocular prostheses. An accelerated aging assay was used for both analyses. Specimens simulating the prosthetic iris in the colors blue, yellow, black, brown and green were fabricated, and were submitted to a colorimetric reading before and after undergoing the thermal conditions of acrylic resin polymerization. Next, the specimens were submitted to an artificial accelerated aging assay with ultraviolet radiation A and weekly colorimetric readings during a 3-week period. The color change (Delta E*) values for the four specimens painted with the same color paint were averaged and the resulting values were considered for statistical analysis. Levine's test and Student's t-test were used to analyze the influence of the temperature of the polymerization cycle during prosthesis fabrication on the color stability of each acrylic resin paint. Friedman's test for three dependent samples was used for analysis of color photodegradation as function of time. Significance level was set at 0.05 for all analyses. It was observed that, after the action of the temperature of the polymerization cycle, alteration above clinically acceptable level of Delta E*> 3.3 was observed only for the yellow color. After the accelerated aging assay, there were statistically significant differences (p<0.05) as a function of time in the green, brown, black and blue colors. Changes were clinically acceptable for the brown and black colors; slightly above the clinically acceptable limit for the green color; and significantly high and impracticable from a clinical standpoint for the blue color. There was no statistically significant differences (p>0.05) for the yellow color, which presented color change only a little above the clinically acceptable limit. IN CONCLUSION: 1. Only the yellow color presented alterations above the clinically acceptable levels after the polymerization cycle; 2. After accelerated aging, there was no changes in the yellow color above the clinically acceptable levels; 3. For the green color, degradation was significant and slightly above the clinically acceptable levels; 4. The black, brown and blue colors presented significant alterations as function of time; the alterations of the brown and black colors were within acceptable clinical levels, while the blue color presented a more accentuated degradation over time.

Mechanical behavior of ethylene vinyl acetate copolymer (EVA) used for fabrication of mouthguards and interocclusal splints.

In the present investigation, an experimental dental arch model fabricated in epoxy was assayed in Kratos universal testing machine to study the mechanical behavior of ethylene and vinyl acetate copolymer (EVA) in the form of mouthguard for sports and flat plate. The following variables were considered: thickness (3 and 4-mm plates), temperature (room and mouth temperature) and presence/absence of artificial saliva. Mechanical properties of EVA were tested under compressive strength: apparent absorbed energy (J.mm-1), maximum tension (N.mm-1), maximum dislocation (mm) and maximum strength (N). Data were recorded and modeled mathematically. Regarding the absorbed energy, maximum tension and maximum force, it was verified that the higher the thickness of the mouthguards, the better the results of force dissipation and redirection to the system and to several regions of the dental arch. In the presence of saliva and close to mouth temperature, the material responded positively to these alterations, resenting increased ductibility as well as improved mechanical responses. Regarding maximum dislocation, it was observed a better accommodation of the occlusion under conditions that simulate those observed in the oral environment. In conclusion, EVA proved to be an adequate material for fabrication of mouthguards and interocclusal splints. In addition, EVA showed good results in force dissipation and demonstrated a shock-absorbing capacity and a great protection potential.

Protetor bucal individualizado, para esporte, específico para Ortodontia / Individualized mouthguard specific to Orthodontics

O uso do protetor bucal para esporte entre atletas deve ser estimulado, Ele protege dentes, lábios e língua contra injúrias ocorridas durante treinos e competições, Em pacientes jovens o grande desafio está na estimulação do uso de protetores bucais para esporte, inclusive quando este jovem atleta está em tratamento ortodõntico com o uso de aparatologia fixa, Observa-se a grande incidência de injúrias contra, principalmente, lábios e língua quando este atleta em tratamento ortodõntico não faz uso de um protetor bucal para esporte individualizado e específico para ortodontia. O objetivo deste trabalho é apresentar uma técnica de confecção de protetor bucal individualizado e específico para atletas que estejam em tratamento ortodontico. Observando as regras internacionais e não interferindo em suas funções básicas como respiração, fala e deglutição

The use of mouthguard for sports among athletes should be encouraqed. It protects teeth, lips and tongue against injuries occurred during training and cornpetitions, In young patients, the challenge is stimulate the use of mouthguards for sports including when this young athlete is in orthodontic treatment using fixed orthodontic appliance. Observe the high incidence of injuries primarily against lips and tongue when this athlete undergoing orthodontic treatment does not make use of a sports mouthguard individualized and specific to orthodontics. The aim of this paper is to present a technique for creating an individualized and specific mouthguard for athletes who are undergoing orthodontic treatment Observing the international standards and not interfering with its basic functions such as breathing, speaking and swallowinq

Estudo do uso potencial da Fitoterapia na higienização de próteses oculares / Study of Phytothrerapy use in the higienization of ocular prosthesis

Introdução - A manutenção da prótese ocular é de grande importância para que possa exercer sua função de reestabelecer estética e manter a cavidade anoftámica livre de infecções e inflamações, muitas vezes causadas pelo manuseio das mesmas. Cuidados básicos como a higienização da prótese podem prolongar sua vida útil, além de garantir a integridade da cavidade anoftalmica. Como muitos pacientes portadores de prótese ocular encontram-se distantes de grandes centros, procurou-se uma alternativa para a higienização da peça através de um fitoterápico com esse potencial, como o Barbatimão (stryphnodndron polyphyllum), árvore presente em grande parte do pais. Material e métodos - Com o intuito de comprovar a eficácia desse procedimento foi realizado um experimento com seis próteses oculares imersas durante quarenta e nove dias em líquido resultante da maceração do fitoterápico. Resultados e conclusões - Concluiu-se que não houve alteração na composição físico-química da peça, podendo-se então indicar esse fitoterápico como agente higienizador de próteses oculares.