Effects of bleaching gel containing TiO2 and chitosan on tooth surface roughness, microhardness and colour.

BACKGROUND: This study aimed to evaluate the effects of an experimental bleaching gel made with TiO2 and chitosan, along with the Opalescence Boost PF and Philips Zoom bleaching agents, on tooth surface roughness, microhardness and colour. MATERIALS AND METHODS: The experimental gel, containing 6% hydrogen peroxide (HP), was evaluated against the two existing treatments, which incorporate 40% and 25% HP. For colour evaluation, 36 human premolar teeth were divided into three groups (n = 12). For surface roughness and microhardness evaluation, 72 bovine incisor samples were divided into six groups (n = 12). Data on colour alteration were analysed with the CIEDE2000 formula. Surface roughness was measured using a profilometer, and microhardness was measured with a Vickers hardness tester. ANOVA was used for statistical analysis. RESULTS: There were no statistically significant differences among the groups for surface roughness, microhardness values or colour change after bleaching (P > 0.05). The lowest bleaching efficacy was observed for the 40% HP agent, and the highest efficacy was observed for the 25% HP agent (P < 0.05). CONCLUSIONS: An experimental 6% HP gel containing TiO2 and chitosan provided effective bleaching without adverse effects on tooth surface roughness or microhardness. The use of TiO2 with chitosan can provide clinicians with positive results.

Phakic iris-claw IOL implantation, with Bursa technique, through a self-sealing scleral tunnel and without iridotomy or iridectomy.

PURPOSE: To present a novel technique for the implantation of phakic iris-claw intraocular lenses (IOL) in highly myopic cases. METHODS: Twelve cases, under the age of 40, with high myopia were included in this retrospective study. The mean follow-up span was 14.4+/-5.8 months. Phakic iris-claw IOL implantation was performed, through a 5.5 or 6.5 mm self sealing scleral tunnel with Bursa technique. No suturing and opening a peripheral iridectomy or iridotomy was required in our study. Pre- and postoperative patient evaluation included manifest and cycloplegic refractions, uncorrected visual acuity, best-corrected visual acuity (BCVA), induced astigmatism, and intraocular pressure (IOP) assessments. RESULTS: All eyes gained one to nine lines of BCVA of the Snellen chart. The vector analysis revealed an induced astigmatism of 0.63 D. No significant IOP change was detected throughout the follow-up. CONCLUSIONS: The data suggest that nonfoldable iris fixated phakic IOL implantation, through a self-sealing incision with Bursa technique, is safe and requires no iridectomy or iridotomy in cases with deep anterior chambers.

Microincisional cataract surgery (MICS) with pulse and burst modes.

PURPOSE: To compare the amount of ultrasound (US) energy and balanced solution (BS) required for burst mode and pulse mode during bimanual phacoemulsification surgery. METHODS: One hundred cases were divided into two groups (the pulse mode Group 1 [50 eyes], the burst mode Group 2 [50 eyes]). One surgeon (M.B.) performed phaco notemulsification procedures using topical anesthesia with the AMO Sovereign in all patients. The technique was based on the nuclear hardness and surgeon's criteria and performed bimanually. The surgery time, total ultrasound time (UST) and effective US power (USP), and used balanced solution (BS) were retrospectively compared. RESULTS: The mean surgery time, mean UST, and mean used BS volume were not statistically different in both groups (p>0.05). The mean EPT was statistically highly different in both groups (p>0.001). There was a slight tendency toward more surgery time in Group 2 than in Group 1, although the difference was not significant (p=0.146). Statistically significant higher results (Group 1: r=0,889, p<0.001, and Group 2: r=0,834, p<0.001) were seen in Group 1 when both groups were evaluated for the surgery time and used BS volume. When UST and used BS volume were evaluated in Groups 1 and 2, significant relation was seen in both but the correlation is statistically higher in Group 1 (Group 1: r=0,765, p<0.001, and Group 2: r=0,544, p<0.001). CONCLUSIONS: The very low energy modes with the WhiteStar technology are suitable for bimanual cataract surgery.

The effect of anterior chamber maintainer on anterior chamber contamination.

PURPOSE: To evaluate the effect of anterior chamber continuous infusion maintainer system on the contamination of anterior chamber in phacoemulsification surgery. METHODS: Clear corneal phacoemulsification surgery was performed in 132 eyes of 132 randomly selected patients with cataract who were divided into two groups of 66 eyes according to the use of an anterior chamber maintainer (ACM) system. The fluid specimens were taken from anterior chamber in the beginning and at the end of the surgery. They were transferred under anaerobic conditions and investigated by culturing onto blood agar and thiogluconate broth media. Differences between the two groups with respect to contamination of the specimens were investigated. RESULTS: The mean age of the group undergoing surgery without a maintainer system (Group A) was 63 +/- 10 years (min = 41, max = 80) versus 59 +/- 10 years (min = 33, max = 80) in the other group (Group B) in which the maintainer was used during surgery. In the postoperative specimen, Micrococcus species were isolated from one eye (1.5%) in Group A and S. pyogenes in one eye (1.5%) from Group B. Mean follow-up interval was 12 +/- 6 (min = 4, max = 28) months. CONCLUSIONS: The use of ACM system in clear corneal phacoemulsification surgery carries no additional risks as far as contamination is concerned.

Retinal detachment after radial keratotomy.

We report the case of a 43-year old woman who developed retinal detachment (RD) after radial keratotomy (RK) for the correction of a 7 D myopia. Further flattening in the corneal topography with a decrease in myopia was noted following RD surgery. Although no cause-effect relationship between RK and RD can be stated, it is imperative to inform the patients that RK only corrects the refractive aspect of myopia.

Treatment of chronic macular oedema with low dosage acetazolamide.

In this study, 46 eyes of 40 patients exhibiting chronic macular oedema have been treated with 125 mg Acetazolamide. The eyes with pseudophakia and the eyes with retinitis pigmentosa obtained considerable beneficial help from this treatment. Our findings indicate that Acetazolamide may offer the clinician an alternative approach in the treatment of central vision threatening chronic macular oedema.