ABSTRACT
This study evaluated the influence of various gingival displays on the esthetic perception in the presence of upper dental midline discrepancy. Methods: A smiling image of a male subject was altered digitally to produce five image series: normal smile (series A), decreased tooth show (series B), increased gingival show (series C), maxillary cant (series D), and asymmetric upper lip elevation (series E). In each image series, the midline was deviated to the right and left incrementally. A total of 210 raters (four professional groups and laypersons, n = 42 in each group) determined the midline deviation threshold and the attractiveness of midline position in each series. Results: The right and left thresholds were statistically similar for the symmetrical series (A, B, and C), while for series D, the right threshold was significantly lower. In most rater groups, the mean threshold order was: B > A > E > C > D. In all the series, the raters selected the coincident midline as the most attractive series except for series D, for which 1–2-mm deviations to the left were selected as the most attractive by almost all the groups. Conclusions: It is crucial to establish the coincident midline position in a symmetrical smile, especially when a gummy smile exists. In the asymmetrical gingival show, a coincident midline might not be the most esthetic midline position.
ABSTRACT
Statement of the Problem: Oral candidiasis is the most common opportunistic infection affecting the human oral cavity. Photodynamic therapy, as one of its proposed treatment modalities, needs a distinct dye for achieving the best effect
Purpose: The purpose of this study was to evaluate photosensitization effects of four distinct dyes on standard suspension of Candida albicans [C. albicans] and Candida dubliniensis [C. dubliniensis] and biofilm of C. albicans considering the obtained optimum dye concentration and duration of laser irradiation
Materials and Method: In this in vitro study, colony forming units [CFU] of two sets of four groups of Laser plus Dye [L+D+], Dye [L-D+], Laser [L+D-] and No Laser, No Dye [L-D-] were assessed individually with different methylene blue concentrations and laser irradiation period. The photodynamic therapy effect on standard suspension of Candida species [using methylene blue, aniline blue, malachite green and crystal violet] were studied based on the obtained results. Similar investigation was performed on biofilm of C. albicans using the spectral absorbance. Data were imported to SPSS and assessed by statistical tests of analysis of variance [ANOVA] and Tukey test [alpha= 0.05]
Results: CFU among the different dye concentration and irradiation time decrease in dose- and time-dependent manner [p> 0.05], all of which were significantly lower than the control groups [p< 0.05]. Among the examined photosensitizers, there was no statistically significant difference, [p> 0.05] though all of them were significantly decrease CFU compared with the control groups [p<0.05]. In L+D- and L+D+ groups, biofilm was significantly destroyed more than that of L-D- [p< 0.05]
Conclusion: Photodynamic therapy might be used as an effective procedure to treat Candida associated mucocutaneous diseases and killing biofilm in the infected surfaces such as dentures
ABSTRACT
Statement of the Problem: Implant-retained overdenture can improve the stability of dentures and prevent bone loss. Overdenture-wearing patients need special hygiene care
Purpose: The aim of this study was to evaluate the effects of various denture cleansers on the retention of Dio orange O-rings
Method and Materials: In this experimental study, 40 Dio orange O-rings were divided into 4 groups [10 O-rings each] and each group was soaked for equivalent of 6 months in the following solutions: 5.25% NaOCl [1:10 dilution], Corega cleanser tabs, Professional cleanser tabs and water [as the control group]. After 6 months, O-rings were tested for 2inch/minutes of tensile force. The peak load-todislodgement was recorded. Data were imported to SPSS18 and were analyzed by One-Way ANOVA and Tukey HSD test [p
Results: Denture cleansing solutions have significant effects on the reduction of retentive value of O-rings [p
Conclusion: This in-vitro study demonstrated that the retention of O-rings was affected when soaked in cleansing solutions. NaOCl caused more reduction in retentive value compared to effervescent cleansers and would not be recommended for cleansing O-rings. These results should be interpreted clinically and the role of other factors in the retention of O-rings should be considered in order to recommend the best cleanser for O-ring overdentures
ABSTRACT
Intraventricular hemorrhage [IVH] is one of the major causes of the cerebral palsy and mental retardation. Prevention and early management of these neurologic developmental problems will require determining the perinatal risk factors associated with this clinical entity. Pneumothorax increase the risk of IVH, and cause of pneumothorax has an important effect in severity of IVH. This is a prospective cross sectional study in 2010. This study includes 150 preterm neonates. Cranial ultrasound was performed in all neonates in age 3, 7, 30, 60, just after pneumothorax and every 2 week until chest tube discontinuation. Then prevalence of IVH and pneumothorax was calculated in preterm infant and severity of IVH was investigated before and after development of pneumothorax, and this comparison was divided by different causes of pneumothorax with SPSS version 11.5. Prevalence of IVH and pneumothorax in preterm infants were 30% and 10% respectively. Pneumothorax was not a risk factor of IVH [P>0.05], but prevalence of pneumothorax caused by RDS was a risk factor of development of IVH [P=0.01]. Also pneumothorax in patients with birth weight less than 1000 g and gestational age less than 28 week was a risk factor of IVH pneumothorax [P=0.008, P=0.01 respectively]. Our study discusses the differences in previous studies about association of pneumothorax and IVH. Also we suggest the hypothesis that lack of cerebral autoregulation in neonates with gestational age less than 28 week can cause IVH development after hypotension induces by pneumothorax.