A nonsense mutation in the tyrosinase gene causes albinism in water buffalo

Background: Oculocutaneous albinism (OCA) is an autosomal recessive hereditary pigmentation disorder affecting humans and several other animal species. Oculocutaneous albinism was studied in a herd of Murrah buffalo to determine the clinical presentation and genetic basis of albinism in this species.Results: Clinical examinations and pedigree analysis were performed in an affected herd, and wild-type and OCA tyrosinase mRNA sequences were obtained. The main clinical findings were photophobia and a lack of pigmentation of the hair, skin, horns, hooves, mucosa, and iris. The results of segregation analysis suggest that this disease is acquired through recessive inheritance. In the OCA buffalo, a single-base substitution was detected at nucleotide 1,431 (G to A), which leads to the conversion of tryptophan into a stop codon at residue 477.Conclusion: This premature stop codon produces an inactive protein, which is responsible for the OCA buffalo phenotype. These findings will be useful for future studies of albinism in buffalo and as a possible model to study diseases caused by a premature stop codon.

Performance and color of broilers fed diets containing Rhodocyclus gelatinosus biomass

The objective of this study was to evaluate the effect of different supplementation levels of Rhodocyclus gelatinosus biomass on the performance and pigmentation of broilers. Cobb broilers were raised in pens and were fed a sorghum-based diet until 35 days of age. At the 36th day of age, ninety-six birds were randomly distributed to four treatments consisting of experimental diets with different supplementation levels of Rhodocyclus gelatinosus biomass (0, 75, 150 and 300 ppm) added to the finisher basal diet, which were given for seven days. A completely randomized experimental design was used, with four treatments, four replicates and six broilers per parcel. Birds and diets were weighed at the 36th and at the 42nd day of age for performance analysis. There was no significant effect on broiler feed intake. Significant differences in weight gain and feed conversion were seen between the control group and the groups supplemented with 75 and 150 ppm. The treatment with the highest supplementation level and the control group had best weight gain and feed conversion. Color analysis showed that R. gelatinosus biomass supplementation resulted in more yellow breast skin and increased darkening and color purity in breast and thigh meat of broilers, but had no effect on lightness or color purity of breast and thigh skins.

Estudo experimental do poliuretano de óleo de mamona (Ricinus communis) como substituto parcial do tendão calcâneo comum em coelhos (Oryctolagus cuniculus)

Com o objetivo de avaliar a eficiência da prótese de poliuretano de mamona como substituto parcial do tendão calcâneo comum, foram utilizadas 30 coelhas da raça Nova Zelândia, entre dois e três meses de idade e peso médio de 2kg. Após anestesia geral, o procedimento cirúrgico em ambos os membros constou de incisão caudo-lateral no sentido longitudinal do terço médio ao distal da tíbia e exposição do tendão calcâneo comum. Após a tenectomia do tendão do músculo gastrocnêmio, a prótese de poliuretano de cerca de 0,5cm de extensão por 0,5cm de diâmetro foi fixada aos cotos proximal e distal do tendão, empregando-se o fio de polipropileno monofilamentar 4-0, conforme técnica modificada de Kessler. A prótese de poliuretano na forma elastomérica revelou propriedades como textura e flexibilidade semelhantes à do tecido tendinoso, pode ser confeccionada na forma e no tamanho almejados e permite ser moldada, cortada e esterilizada por calor úmido. Todos os animais apoiaram os membros operados imediatamente após o retorno anestésico. Não se observaram sinais clínicos de infecção e não ocorreu deiscência de ferida. Percebeu-se aumento de volume local devido ao edema, evidente na primeira semana pós-cirúrgica, que gradualmente desapareceu . À palpação foi possível delimitar com facilidade a prótese que se conservou fixa no local e intacta. Clinicamente o poliuretano de mamona não induziu reação desfavorável que comprometesse a cicatrização tendínea, podendo ser indicado como substituto temporário de tendão.

Evaluation of Torque Maintenance of Abutment and Cylinder Screws With Morse Taper Implants

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

Planning for Immediate Loading of Implant-Supported Prostheses: Literature Review

The aim of this study was to present the factors that influence planning for immediate loading of implants through a literature review for treatment success. Research was conducted in the PubMed database including the key words immediate implant loading, implant-supported prostheses, and implant planning for studies published from 2000 to 2011. Forty-eight articles were used in this review to describe the indications and counterindications, presurgical planning, and technologies available for planning of this treatment alternative.

Prosthetic Platforms in Implant Dentistry

The use of implant-supported prosthesis to replace missing teeth became a predictable treatment. Although high success rate has been reported, implant treatment is suitable to complications, failures, and limitations such as peri-implant bone loss after implant loading. Stress evaluation on the bone-abutment-implant interface has been carried out to develop new designs of prosthetic platform and to understand the stress distribution in this interface. Several types of prosthetic platforms are available such as external and internal hexagon, Morse cone connection, and the concept of platform switching. Therefore, this study aimed to critically describe the different options of prosthetic platforms in implant dentistry, by discussing their biomechanical concepts, clinical use, and advantages and disadvantages. It was observed that all types of prosthetic platforms provided high success rate of the implant treatment by following a strict criteria of indication and limitation. In conclusion, a reverse planning of implant treatment is strongly indicated to reduce implant overload, and the use of advanced surgical-prosthetic techniques is required to obtain a long-term success of oral rehabilitations.

Clinical Viability for Immediate Loading of Dental Implants: Part II-Treatment Alternatives

The treatment with implants aims to obtain a direct interface between bone and implant. The implant is kept load-free during 4 to 6 months in the 2-stage procedure, which is considered a requisite for osseointegration. However, this period is based on empirical principles and uncomfortable for patient. So, the immediate loading protocol was Suggested to submit implants to occlusal function after placement. This protocol has been applied for several conditions of edentulism. The aim of this study was to evaluate the treatment alternatives for immediate loading of complete and partial edentulous patients. In general, the studies have demonstrated high previsibility for rehabilitation of complete edentulous arches with full-arch, implant-supported prosthesis. The rehabilitation with immediate loading for maxillary overdenture is questionable because there is no longitudinal study in literature. The studies with partial edentulous arches have demonstrated high success rates for implants placed in the mandibular and maxillary anterior region. Additional care is recommended for posterior region mainly in the maxillary arch, and further studies are suggested to corroborate this treatment.

Clinical Viability of Immediate Loading of Dental Implants: Part I-Factors for Success

Two-stage procedure for dental implants presents corroborated clinical success over 40 years. The evolution of surgical techniques, development of diagnostic methods, knowledge about tissue biology, and quality of implants regarding design and surface supported studies with I surgical stage followed by immediate prosthesis placement. However, several factors influence the treatment success with immediate loading. SO, this Study aimed to evaluate some factors regarding the success and characteristics of implants and patients.

Digital Radiographic Evaluation of the Level of Alveolar Bone Crest in External Hexagon Implants Submitted to 2 Types of Implant Abutments Under Immediate Loading

Purpose: The aim of this study was to evaluate by means of digital radiography the behavior of the alveolar bone crest in external hexagon implants following the use of 2 different types of abutments, one for conventional cemented prosthesis and one for modified cemented prosthesis.Methods: Ten external hexagon implants (platform 4.1) were placed in 5 patients. Initial instrumentation was carried out to obtain primary stability of the temporary prostheses under immediate loading. Each patient received both abutments for conventional and modified cemented prosthesis. Standardized digital periapical radiographies were performed at times T0 (immediately after implant placement) and T1 (4 months after implant placement). A straight line was initially established from the implant platform to the distal and mesial periimplantar marginal bone tissue (immediately in contact with the implant) and measured by digital radiography, using Sidexis version 2.3 (Sirona Dental Systems GmbH, Bensheim, Germany) software. The data were submitted to paired-samples t-test analysis.Results: There was no significant difference between the conventional and modified cemented prosthesis. In both cases, t-test results were within the null hypothesis level.Conclusion: The abutment for the modified cemented prosthesis resulted in no significant radiographic difference of alveolar bone crest height, when compared with the conventional cemented prostheses.

Treatment of root surface in delayed tooth replantation: a review of literature

The time elapsed between a trauma and tooth replantation usually ranges from 1 to 4 h. The chances of root surface damage are higher when tooth replantation is not performed immediately or if the avulsed tooth is not stored in an adequate medium. This invariably leads to necrosis of pulp tissue, periodontal ligament cells and cementum, thus increasing the possibility of root resorption, which is the main cause of loss of replanted teeth. This paper presents a comprehensive review of literature on root surface treatments performed in cases of delayed tooth replantation with necrotic cemental periodontal ligament. Journal articles retrieved from PubMed/MedLine, Bireme and Scielo databases were reviewed. It was observed that, when there are no periodontal ligament remnants and contamination is under control, replacement resorption and ankylosis are the best results and that, although these events will end up leading to tooth loss, this will happen slowly with no loss of the alveolar ridge height, which is important for future prosthesis planning.

Anterior Tooth Rehabilitation With Frozen Homogenous Bone Graft and Immediately Loaded Titanium Implant Using Computer-Guided Surgery

Computed tomographic scanning is a precise, noinvasive surveying technique that enables the professionals to improve the precision of implant placement by building a prototype that allows the confection of surgical guides. The authors present a clinical case of anterior tooth rehabilitation with frozen homogenous bone graft and immediately loaded titanium implant using computer-guided surgery. A multislice computed tomography was realized, and a prototype was built. All the procedures were previously realized in the prototype before started in the patient. This technique allows a better surgical planning, makes the procedures more accurate, and reduces surgery time.

Evaluation of Satisfaction of Patients Rehabilitated With Zygomatic Fixtures

Purpose: The aim of this study was to evaluate the satisfaction of patients rehabilitated with zygomatic fixtures and prosthesis with immediate loading.Materials and Methods: The study selected patients who were rehabilitated with zygomatic implants at the clinic of the Latin American Institute for Dental Research and Education (ILAPEO. Curitiba-PR. Brasil) between 2005 and 2009. The patients were asked to answer a control-questionnaire during their follow-up visits. Data were collected regarding the level of patient satisfaction, reason for dissatisfaction, number of post-operative clinical sessions, and the type of complication. Sixteen patients were selected: 10 females and 6 males.Results: Half of the patients were completely satisfied while the other half were satisfied with some complaints. The complaints were related to hygiene, esthetics, phonetics, and discomfort during chewing. Regarding the post-operative evaluation, 50% of the patients were attended due to the prosthesis (62.5%) and the implant (37.5%).Conclusions: The treatment with zygomatic fixtures is predictable and reliable. The patients were satisfied both with implants and prosthesis. (C) 2012 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 70: 314-319, 2012

Photoelastic Analysis of the Influence of Platform Switching on Stress Distribution in Implants

The aim of this study was to evaluate the stress distribution of platform switching implants using a photoelastic method. Three models were constructed of the photoelastic resin PL-2, with a single implant and a screw-retained implant-supported prosthesis. These models were Model A, platform 5.0 mm/abutment 4.1 mm; Model B, platform 4.1 mm/abutment 4.1 mm; and Model C, platform 5.00 mm/abutment 5.00 mm. Axial and oblique (45 degrees) loads of 100 N were applied using a Universal Testing Machine (EMIC DL 3000). Images were photographed with a digital camera and visualized with software (AdobePhotoshop) to facilitate the qualitative analysis. The highest stress concentrations were observed at the apical third of the 3 models. With the oblique load, the highest stress concentrations were located at the implant apex, opposite the load application. Stress concentrations decreased in the cervical region of Model A (platform switching), and Models A (platform switching) and C (conventional/wide-diameter) displayed similar stress magnitudes. Finally, Model B (conventional/regular diameter) displayed the highest stress concentrations of the models tested.

Flabby Ridge Correction Using an Auxiliary Technique With Connective Tissue Graft

A common finding in patients with edentulous maxilla and partially dentate mandible is mainly the presence of flabbiness in the anterior edentulous alveolar ridge that can compromise the retention and stability of a denture. Thus, this case report presents the correction of a flabby ridge, using an auxiliary technique combining surgical excision and autogenous connective tissue grafting. The technique improved the quality of the osteomucosal support of the alveolar ridge and increased the vestibule deepness, whose result increased the success rate of the new conventional total prosthesis.

Periodontal and Prosthetic Biologic Considerations to Restore Biological Width in Posterior Teeth

\ The biologic width is an essential dental space that always needs to be maintained to ensure periodontal health in any dental prosthetic restorations. An iatrogenic partial fixed prosthesis constructed in lower posterior teeth predisposed the development of subgingival caries, which induced violation of the biologic width in involved teeth, resulting in an uncontrolled inflammatory process and periodontal tissue destruction. This clinical report describes a periodontal surgical technique to recover a violated biologic width in lower posterior teeth, by crown lengthening procedure associated with free gingival graft procedure, to ensure the possibility to place a modified partial fixed prosthesis in treated area. The procedure applied to recover the biologic width was crown lengthening with some modifications, associated with modified partial fixed prosthesis to achieve health in treated area. The modified techniques in both surgical and prosthetic procedures were applied to compensate the contraindications to recover biologic width by osteotomy in lower posterior teeth. The result, after 4 years under periodic control, seems to achieve the projected goal. Treating a dental diseased area is necessary to diagnose, eliminate, or control all etiologic factors involved in the process. When the traditional methods are not effective to recover destructed tissues, an alternative, compensatory, and adaptive procedure may be applied to restore the sequelae of the disease, applying a restorative method that respects the biology of involved tissues.