The influence of cavity configuration on the microtensile bond strength between composite resin and dentin / 대한치과보존학회지

This study was conducted to evaluate the influence of the C-factor on the bond strength of a 6th generation self-etching system by measuring the microtensile bond strength of four types of restorations classified by different C-factors with an identical depth of dentin. Eighty human molars were divided into four experimental groups, each of which had a C-factor of 0.25, 2, 3 or 4. Each group was then further divided into four subgroups based on the adhesive and composite resin used. The adhesives used for this study were AQ Bond Plus (Sun Medical, Japan) and Xeno III (DENTSPLY, Germany). And composite resins used were Fantasista (Sun Medical, Japan) and Ceram-X mono (DENTSPLY, Germany). The results were then analyzed using one-way ANOVA, a Tukey's test, and a Pearson's correlation test and were as follows. 1. There was no significant difference among C-factor groups with the exception of groups of Xeno III and Ceram-X mono (p < 0.05). 2. There was no significant difference between any of the adhesives and composite resins in groups with C-factor 0.25, 2 and 4. 3. There was no correlation between the change in C-factor and microtensile bond strength in the Fantasista groups. It was concluded that the C-factor of cavities does not have a significant effect on the microtensile bond strength of the restorations when cavities of the same depth of dentin are restored using composite resin in conjunction with the 6th generation self-etching system.

The Factors Influencing the Outcome of Trabeculectomy in the Medically Uncontrolled Primary Angle-Closure Glaucoma

PURPOSE: To determine the factors that influence the outcome of trabeculectomy in eyes with medically uncontrolled primary angle-closure glaucoma (PACG). METHODS: The records of 70 eyes of 57 patients who had undergone trabeculectomy were reviewed. Success was defined as intraocular pressure of 21 mm Hg or less with or without antiglaucoma medications and no additional glaucoma surgery, phthisis, or loss of light perception. RESULTS: Postoperative success was obtained in 64 (91.4%) out of 70 eyes after a mean follow-up period of 28.9+/-23.7 months. The life-table success rate was 92.3% at 1 year and 88.0% at 5 years. Postoperative shallow anterior chamber was a significant risk factor for surgical failure (Cox proportional hazards regression analysis, hazard ratio, 27.8; 95% confidence interval, 2.6 to 297.5; p=0.005). Medically uncontrolled acute PACG in which trabeculectomy performed as an urgent surgical intervention, as opposed to medically uncontrolled chronic PACG, was a borderline risk factor (hazard ratio, 4.0; 95% confidence interval, 0.6 to 176.8; p=0.04). Factors found to be not significant included gender, refraction, visual acuity before surgery, preoperative number of antiglaucoma medications, presenting intraocular pressure, history of acute attack, previous peripheral iridectomy, mid-dilated pupil, glaukomflecken, iris atrophy, glaucomatous optic disc, and visual field damage. CONCLUSIONS: Postoperative shallow anterior chamber and medically uncontrolled acute PACG appear to have an adverse effect on the outcome of trabeculectomy. Success of trabeculectomy in PACG seems to be not related with the signs of damage from elevated intraocular pressure.

The Results and Factors Influencing the Outcome of Mitomycin C Trabeculectomy in Neovascular Glaucoma

PURPOSE: To evaluate the outcome and factors that influence the outcome of trabeculectomy with adjunctive mitomycin C in eyes with medically uncontrolled neovascular glaucoma. METHODS: The records of 38 eyes who underwent mitomycin C trabeculectomies were reviewed. Success was defined as intraocular pressure of 21 mm Hg or less with or without glaucoma medications and no additional glaucoma surgery, phthisis, or loss of light perception. RESULTS: Postoperative success was obtained in 22 (57.9%) out of 38 eyes after a mean follow-up period of 18.0+/-18.9 months. The success rate was 57.9% at 1 year and 51.4% at 2 years. The main causes for failure were inadequate IOP control in 34.2% (13/38), loss of light perception in 23.5% (8/34), and progression to phthisis bulbi in 2.6% (1/38). Age of 50 years or younger was a significant risk factor for surgical failure (hazard ratio, 10.5; 95% confidence interval, 1.7 to 63.7; p=0.01). CONCLUSIONS: Trabeculectomy with mitomycin C was generally effective for the treatment of neovascular glaucoma, especially in patients over 50 years of age. However, visual loss in eyes with neovascular glaucoma was common.

Electron Microscopic Study of the Corneal Nerve by Flat Serial Section

PURPOSE: This study was performed to describe the ultrastructure of stromal nerve fibers in central, mid-peripheral, and peripheral parts of the human cornea by flat serial corneal section. METHODS: Seven samples from fresh normal cornea, derived from eyes with retinoblastoma and eyes from eye bank, were processed for transmission electron microscopic examinations. Flat serial sections reaching from mid-epithelium to the anterior stroma were observed. RESULTS: The myelinated and unmyelinated nerve fibers are alternately arranged and run parallel to the stromal collagen fibers at the periphery of the cornea. The main difference between the limbal and the central cornea is the presence of myelinated nerve fibers in the anterior peripheral stroma. The diameter of the unmyelinated nerve fiber measures between 0.25 and 0.63 micrometer in size. The corneal nerve fibers contain vesicles, mitochondria, and glycogen particles. The peripheral nerve fibers contain both clear and dense vesicles. The nerve fiber is separated by an interval of 0.3 micrometer from the cytoplasmic wall of keratocyte at the center of the cornea. CONCLUSIONS: The majority of the corneal nerve fibers can be classified as C-fibers due to their size. The presence of both clear and dense vesicles within the cytoplasm of the periphery of the cornea suggest that a small portion in the peripheral corneal nerve may be originated from the sympathetic nervous system. A close vicinity between the nerve fibers and keratocyte supports that nerve fibers might modulate the release of growth factors in the regulation of stromal and epithelial metabolism.