Combined effects of soft drinks and nicotine on Streptococcus mutans metabolic activity and biofilm formation.

The purpose of this study was to explore the effects of nicotine on the activity of Streptococcus mutans (S. mutans) in soft drinks. Regular soft drinks contain large proportions of high-fructose corn syrup (HFCS), which increases the activity of S. mutans resulting in high-caries risk compared with sugar-free soft drinks. Nicotine use exhibits a strong correlation with increased S. mutans biofilm formation. The soft drinks chosen were (Coca-Cola Classic, Diet Coke, Coca-Cola Zero Sugar, Caffeine-Free Coca-Cola, Caffeine-Free Diet Coke, Caffeine-Free Coca-Cola Zero Sugar). S. mutans was grown overnight in tryptic soy broth; nicotine was diluted in tryptic soy broth supplemented with 1.0% sucrose followed by soft drinks in dilution of 1:3. Total growth absorbance and biofilm growth were determined by spectrophotometry, absorbance measured to determine biofilm formation, and metabolic activity quantified. One-way ANOVA showed a considerable effect for HFCS and caffeine in the presence of nicotine and their interaction in all measures. Results showed sugar-free caffeinated colas demonstrated significant effect in inhibiting S. mutans biofilm formation and metabolic activity with nicotine. Nicotine-induced S. mutans increased biofilm formation and metabolic activity in the presence of HFCS and caffeine in soft drinks. In conclusion, smokers should consider sugar-free caffeinated versions to minimize the chance of developing dental caries dut to the reduction of biofilm formation.

The effects of charcoal dentifrices on Streptococcus mutans biofilm development and enamel demineralization.

PURPOSE: To evaluate the in vitro effects of commercially available charcoal dentifrices on Streptococcus mutans biofilm development and their ability to prevent enamel demineralization. METHODS: Streptococcus mutans biofilm was formed on polished bovine enamel specimens (n= 9 per treatment), and treated twice-daily for 120 seconds over the course of 5 days with: charcoal dentifrice containing fluoride (1,000 ppm F) (CF+), fluoride-free charcoal dentifrice (CF-), regular fluoride (1,100 ppm F) dentifrice (F+ ), or regular fluoride-free dentifrice (F-). Chlorhexidine (CHX, 0.12%) and deionized water (DIW) were used as positive and negative controls, respectively. Biofilms were analyzed for bacterial viability (colony-forming units, CFU). The pH of the medium was measured daily. Enamel specimens were analyzed using Vickers microhardness ( HV) and transversal microradiography (TMR). Data were analyzed using one-way ANOVA followed by post-hoc tests (α= 0.05). RESULTS: F+ showed higher pH values than CF+ and CF-, and CF- presented higher pH than CF+, showing that CF+ did not have inhibitory effects on the acidogenicity of cariogenic biofilms. CFU was significantly decreased when specimens were treated with CF+, CF- and F+, compared to specimens treated with DIW (P≤ 0.035) or F- (P≤ 0.001), respectively. However, the reduction observed was minimal (approximately 1 log). CF+ and CF- were less effective than F+ in preventing enamel demineralization as determined using HV (P= 0.041 and P= 0.003, respectively) and TMR ( P≤ 0.001). Both charcoal dentifrices (CF+, CF-) did not show relevant inhibition of S. mutans biofilm growth. Additionally, neither product prevented enamel demineralization compared to a regular fluoride-containing dentifrice. CLINICAL SIGNIFICANCE: The tested charcoal dentifrices did not exhibit anticaries potential.

Botulinum Toxin for the Treatment of Gummv Smile.

AIM: The aim was to evaluate the effect of botulinum toxin (Botox) injections as a conservative treatment for gummy smile. MATERIALS AND METHODS: An experimental in vivo study was conducted at a dermatology clinic in Riyadh in January 2016. The study included 23 female patients who ranged from 20 to 50 years and were treated with Botox injections due to excessive maxillary gingival display. The patients with short clinical crowns or long maxilla, those who were pregnant or breastfeeding, and patients with neuromuscular disorders were excluded. Patients received Botox type I, injected 3 mm lateral to the alar-fascial groove at the level of the nostril opening at the insertion of the levator labii superioris alaeque nasi muscle. Photos were taken of the patient's smile before and after the treatment and were then uploaded to the SketchUp program to calculate improvements in gingival display. The distance from the lower margin of the upper lip to the gingival margin was calculated pre- and posttreatment. The amount of improvement was calculated as (pre-Botox treatment - post-Botox treatment/pre-Botox treatment × 100). The mean percentage of the total improvement was analyzed. RESULTS: A total of 23 female patients received treatment to improve their gummy smile. Improvement was clear 2 weeks after Botox injection. The mean percentage of improvement in the gingival display was 99.6%. CONCLUSION: Botox type I is an effective conservative technique to improve gummy smile caused by muscular hyperfunction. CLINICAL SIGNIFICANCE: Patients' retention highly indicated that they were satisfied with the provided treatment by Botox injections. Improving the quality of life with least painful experience and immediate results was the major advantage for Botox type I.