ABSTRACT
The purpose of this study was: (1) to compare nanoleakage patterns of a conventional 3-step etch and rinse adhesive system and two experimental hydrophobic adhesive systems and (2) to investigate the change of the nanoleakage patterns after load cycling. Two kinds of hydrophobic experimental adhesives, ethanol containing adhesive (EA) and methanol containing adhesive (MA), were prepared. Thirty extracted human molars were embedded in resin blocks and occlusal thirds of the crowns were removed. The polished dentin surfaces were etched with a 35% phosphoric acid etching gel and rinsed with water. Scotchbond Multi-Purpose (MP), EA and MA were used for bonding procedure. Z-250 composite resin was built-up on the adhesive-treated surfaces. Five teeth of each dentin adhesive group were subjected to mechanical load cycling. The teeth were sectioned into 2 mm thick slabs and then stained with 50% ammoniacal silver nitrate. Ten specimens for each group were examined under scanning electron microscope in backscattering electron mode. All photographs were analyzed using image analysis software. Three regions of each specimen were used for evaluation of the silver uptake within the hybrid layer. The area of silver deposition was calculated and expressed in gray value. Data were statistically analyzed by two-way ANOVA and post-hoc testing of multiple comparisons was done with the Scheffe's test. Silver particles were observed in all the groups. However, silver particles were more sparsely distributed in the EA group and the MA group than in the MP group (p < .0001). There were no changes in nanoleakage patterns after load cycling.
Subject(s)
Humans , Adhesives , Chimera , Crowns , Dentin , Electrons , Ethanol , Methanol , Molar , Phosphoric Acids , Resin Cements , Silver , Silver Nitrate , Tooth , WaterABSTRACT
Repeated throwing of baseballs by juvenile pitchers is known to cause damages to bone and cartilage as well as soft tissue in the involved upper extremity. Authors present 4 cases of osteochondral lesion at capitellum of the humerus as a result of repeated insult by throwing baseballs in the juvenile pitchers. Pain and limitation of extension of the affected elbow were the commonest symptoms. Cystic change or osteochondral loose body was found on plain X-ray. Treatment consisted of rest and analgesic administration in the patient who has no loose body, while in case of having loose body it was removed surgically without further treatment to the crater. In spite of the rapid relief of the pain by these treatment, limitation of extension persisted for considerable period of time. It is strongly suggested not to overlook elbow pain in young adolescent whose bone is still growing and who can hardly withstand repeated insult to prevent the development of baseball elbow.
Subject(s)
Adolescent , Humans , Baseball , Cartilage , Elbow , Humerus , Osteochondritis , Upper ExtremityABSTRACT
No abstract available in English.