Evaluation of an alternative technique to optimize direct bonding of orthodontic brackets to temporary crowns

OBJECTIVE: To compare shear bond strength of different direct bonding techniques of orthodontic brackets to acrylic resin surfaces.METHODS: The sample comprised 64 discs of chemically activated acrylic resin (CAAR) randomly divided into four groups: discs in group 1 were bonded by means of light-cured composite resin (conventional adhesive); discs in group 2 had surfaces roughened with a diamond bur followed by conventional direct bonding by means of light-cured composite resin; discs in group 3 were bonded by means of CAAR (alternative adhesive); and discs in group 4 had surfaces roughened with a diamond bur followed by direct bonding by means of CAAR. Shear bond strength values were determined after 24 hours by means of a universal testing machine at a speed of 0.5 mm/min, and compared by analysis of variance followed by post-hoc Tukey test. Adhesive remnant index (ARI) was measured and compared among groups by means of Kruskal-Wallis and Dunn tests.RESULTS: Groups 3 and 4 had significantly greater shear bond strength values in comparison to groups 1 and 2. Groups 3 and 4 yielded similar results. Group 2 showed better results when compared to group 1. In ARI analyses, groups 1 and 2 predominantly exhibited a score equal to 0, whereas groups 3 and 4 predominantly exhibited a score equal to 3.CONCLUSIONS: Direct bonding of brackets to acrylic resin surfaces using CAAR yielded better results than light-cured composite resin. Surface preparation with diamond bur only increased shear bond strength in group 2.

OBJETIVO: comparar a resistência ao cisalhamento de diferentes técnicas para colagem direta de braquetes ortodônticos em superfície de resina acrílica.MÉTODOS: sessenta e quatro (64) discos de resina acrílica ativada quimicamente (RAAQ) foram divididos aleatoriamente em qautro grupos: grupo 1 = colagem com resina composta fotopolimerizável (adesivo convencional); grupo 2 = superfície abrasionada com broca diamantada e colagem com resina composta fotopolimerizável; grupo 3 = colagem com RAAQ (adesivo alternativo); grupo 4 = superfície abrasionada com broca diamantada e colagem com RAAQ. A resistência ao cisalhamento foi avaliada 24h após a colagem, utilizando-se uma máquina universal de ensaios, operando a uma velocidade de 0,5mm/min, e comparada por meio da análise de variância, seguida pelo teste post-hoc de Tukey. O índice de adesivo remanescente (IAR) foi mensurado e comparado entre os grupos por meio dos testes Kruskal-Wallis e Dunn.RESULTADOS: os grupos 3 e 4 demonstraram resistência ao cisalhamento significativamente maior do que os grupos 1 e 2. Os grupos 3 e 4 apresentaram resultados similares. O grupo 2 apresentou melhores resultados do que o grupo 1. Na análise do IAR, observou-se predominância do escore 0 para os grupos 1 e 2 e do escore 3 para os grupos 3 e 4.CONCLUSÕES: a colagem do braquete em superfície de resina acrílica utilizando-se a RAAQ apresentou melhores resultados do que a colagem com resina composta fotopolimerizável. A abrasão da superfície com broca diamantada apenas aumentou a resistência ao cisalhamento no grupo 2.

Morphological aspects of tympanic bulla after ventral osteotomy in cats / Aspectos morfológicos da bulla tympanica de gatos após osteotomia ventral

PURPOSE: To evaluate tympanic bulla healing after experimental ventral osteotomy in cats. METHODS: Twenty adult cats were submitted to unilateral ventral bulla osteotomy and divided into two groups: cats of A1 group (n=10) were euthanized at 8 weeks and cats of A2 group (n=10), at 16 weeks postoperative. RESULTS: Signs of Horner's syndrome or damage to the inner ear were not found. Open-mouth radiographs taken in the immediate postoperative showed interruption in the contour of the larger compartment of the operated bulla. The result of Mcnemar'test was significant in A2 group (*p=0.0156). Macroscopic exams revealed that the operated bullae were similar to the normal ones, with preservation of the tympanic cavity. Connective tissue at the osteotomy site of the larger compartment was significantly found in the operated bullae in both groups (McNemar test: A1 p=0.0020*; A2 p=0.0078*). Histomorphometric analyses showed that the connective tissue length at the osteotomy site was shorter in A2 group than in the A1 group (Mann-Whitney test: p=0.0021*). CONCLUSIONS: Experimental ventral osteotomy did not alter significantly the tympanic bulla conformation and complete regeneration of tympanic bulla frequently did not occur before 16 weeks of postoperative period.

OBJETIVO: Avaliar a morfologia da bulla tympanica de gatos após osteotomia ventral unilateral. MÉTODOS: Foram utilizados 20 gatos distribuídos em dois grupos de 10 animais cada, de acordo com o período de observação: A1 (8 semanas) e A2 (16 semanas). RESULTADOS: Nenhum animal apresentou síndrome de Horner ou lesão do ouvido interno. Nas radiografias em projeção com a boca aberta realizadas no pós-operatório imediato observou-se a interrupção do compartimento maior da bulla tympanica operada, resultado significante no grupo A2 (McNemar, p=0,0156*). Os exames macroscópicos revelaram que a bulla tympanica operada apresentava conformação semelhante a da bulla tympanica normal, com preservação da cavidade timpânica. Na maioria das bullae tympanicae operadas observou-se a presença de tecido conjuntivo na área de osteotomia. O resultado do teste de McNemar foi significante em ambos os grupos (A1, p=0,0020*; A2, p=0,0078*). Os exames histomorfométricos demonstraram que a extensão de tecido conjuntivo presente no local da osteotomia do compartimento maior era menor nas bullae tympanicae operadas do grupo A2 (Mann-Whitney, p=0,0021*). CONCLUSÕES: A osteotomia ventral não alterou de maneira significativa a conformação da bulla tympanica. A regeneração total da bulla tympanica geralmente não ocorreu antes de 16 semanas de pós-operatório.

Surgical correction of pectus excavatum in two cats

Two sexually intact male Bengal cats, one a 4-month-old weighing 2.8 kg and the other, a 3-month-old weighing 2.0 kg, were presented to the University of Missouri-Columbia Veterinary Teaching Hospital for evaluation of respiratory distress. On initial presentation, both cats were dyspneic, exercise intolerant, and had marked concave deformation of the caudal sternum. Surgical correction of pectus excavatum was performed using a cylindrical external splint and U-shaped xternal splint. Post-operative thoracic radiography revealed that there was decreased concavity of the sternum and increased thoracic height at the level of the caudal sternebrae in both cats.

Primary entropion in persian cats

Entropion is defined as the inward rolling of the eyelid margin in which the eyelashes and eyelid hair (frequently the lower lateral lid) rub the cornea. Etiologies may be congenital, spastic, or cicatricial. This condition usually causes epiphora, blepharospasm, photophobia, conjunctivitis, purulent discharge, corneal vascularization, pigmentation and ulceration, if not surgically treated. Congenital entropion commonly affects dogs and is frequently hereditary in some breeds, whereas cats are uncommonly affected. A predilection for the Persian breed to present primary entropion has been suggested. The authors report two cases of entropion in Persian cats referred to the Ophthalmology Section of Veterinary College of Säo Paulo State University - UNESP, Jaboticabal - SP / Brazil. First case: a male Persian cat, 2 years old, with a history of bilateral ocular irritation and purulent discharge for 8 months. Ophthalmic examination revealed epiphora, blepharospasm, photophobia, bilateral entropion affecting the whole length of the lower eyelids, conjunctivitis and purulent discharge. Second case: a male Persian cat, 1 year old, with a history of bilateral ocular irritation and purulent discharge for 3 weeks. At ophthalmic examination the animal was presenting epiphora, blepharospasm, photophobia, bilateral entropion affecting the whole length of the lower lids, conjunctivitis, purulent discharge, corneal vascularization, superficial ulceration and edema. The entropion persisted after topical anaestesia in both cats. Surgical treatment was similar in both cases, based on the modified Holtz-Celsus procedure. Grid keratotomy procedure was also performed in the second case. Both cats had a satisfactory clinic evolution which was confirmed few days after surgery.