Background and aims: Bleaching might affect structural properties of composite materials, and lead to monomer release. This study aimed to evaluate the effect of Laser-assisted and conventional in-office bleaching on the release of BIS-GMA, TEGDMA, and UDMA monomers from a nanohybrid and a microhybrid BIS-GMA based composite. Material and Methods: 32 samples of each composite, were divided into 4 subgroups; subgroup 1: Conventional in-office bleaching (CIB) with the Opalescence Boost PF 38% gel, subgroup 2: Laser-assisted bleaching (LBO) with the Opalescence Boost PF 38% gel, subgroup 3: Laser-assisted bleaching (LBH) with the JW Power bleaching gel, subgroup 4: (CO) control without bleaching. All the samples were immersed in tubes of 2cc Ethanol 75% medium. The released monomers were analyzed using the high performance liquid chromatography (HPLC) method 24 h, 7, and 28 days. Data's were analyzed by Univariate Analysis of Variance test followed by Tukeys HSD. Results: The amount of TEGDMA monomer released was not significant. However, nanohybrid composites showed significantly more monomer release than microhybrid composites (P < 0.05). For UDMA the interaction was significant only after 1 week. In microhybrid composites, the CO subgroup showed more monomer release than LBH and LBO. In nanohybrid composites, LBH showed more monomer release than CIB and CO subgroups. For BIS-GMA monomers the interaction was significant at all time periods and the LBH subgroup of nanohybrid composite had significantly more BIS_GMA release in comparison to other subgroups. Conclusion: Bleaching by laser with JW Power Bleaching gel led to more monomer release in nanohybrid composite.
Background and Aims: Pandrug-resistant Acinetobacter baumannii (PDRAB) are including colistin resistant starins (CoRAB) which cause infections potentially untreatable infections. Recently, incidence of these strains are increasing worldwide. Therefore, new approaches, methods and strategies are urgently needed for treatment and eradication of infections due to PDRAB. So the aim of this study was to evaluate the efficacy of photodynamic therapy (PDT) in combination treatment with colistin against PDRAB. Materials and Methods: PDRAB which was isolated from burn patients was used as a test strain. PDT carried out in which toluidine blue O (TBO) and light-emitting diode (LED) were used as photosensitizer and radiation source, respectively. Then, the effect of PDT plus colistin was evaluated on CoRAB and the colony-forming units of each tested groups calculated. Finally, confirmation of antibacterial activity of combination therapy was carried out using scanning electron microscope. Results: PDT declined bacterial count in comparing with control group by 83.7% of killing percentage, in other words, less than one log reduction. While PDT in combination with colistin showed high synergetic effect against A. baumannii in all concentrations of colistin tested by 100% of killing percentage with 9-log reduction Conclusions: According to our results, PDT alone couldn't eliminate all of the treated bacterial cells. But when combined with colistin, it killed all of the treated bacterial cells in all tested concentrations. Also PDT decreased the minimal inhibitory concentration of colistin against PDRAB by more than 11 fold.
Background and aim: production of collagen by fibroblast cells is a key component in wound healing. Several studies have shown that low level laser therapy (LLLT) and propolis extract stimulate collagen Type I production. The aim of this study is to evaluation the combined effect of LLL helium neon (632.8 nm) and Iranian propolis extract on collagen Type I gene expression by human gingival fibroblasts (HGF3-PI 53). Methods and materials:Human gingival fibroblasts after culturing divided into six experimental groups: G1-control group, which received no irradiation and propolis extract, G2-irradiated at1.5 J/cm², G3-irradiated at 0.15 J/cm², G4-recived extract of propolis, G5- combined extract of propolis and 1.5 J/cm² laser irradiation and G6- combined extract of propolis and 0.15 J/cm² laser irradiation. The experiments were conducted in triplicate. After 24 hour, the total RNA was extracted and cDNA synthesis was performed. Type I collagen mRNA expression was determined with real time PCR. Results:The obtained results illustrated a statistically significant difference between G3 (0.15 J/cm²) and G1 (control group) in levels of collagen Type I messenger RNA (mRNA) expression (p<0.05). The irradiated cells showed a 1.4 times increase in mRNA expression of the collagen Type I gene. Expression of this gene decreases in other groups that this difference was statistically significant. Conclusions:LLLT in different dosage and propolis extract may result in decreased or increased collagen type I gene expression. However this effect should be investigated in clinical studies.
Background and Aims: The aim was comparison of enamel remineralization after application of APF, TiF4 and CO2 laser alone or in combination. Materials and Methods: Enamel blocks were prepared from human third molars. The initial surface hardness was determined by Vicker's hardness tester. The samples underwent a demineralization regimen for 7 days to produce artificial initial caries. The hardness of enamel blocks with white spot lesions was measured, and the samples which had the mean hardness change of 65-90%, were selected, and randomly divided into 5 groups (N=15): G1: control; G2: APF 1.23%; G3: TiF4 4%; G4: TiF4 4% followed by CO2 laser (10.6 μm wavelength, 1 W peak power, 10 ms pulse duration, 500 ms repeat time, 0.2 mm beam spot size, 2 cm distance); G5: CO2 laser (same parameters) followed by TiF4 4%. Surface hardness recovery was measured after the treatments. Three samples in each group were observed under scanning electron microscope at x1,000 magnification. Data were analyzed by repeated measure ANOVA and Bonferrouni tests. Significance level was set at 0.05.. Results: G2, G3, G4 indicated significant differences with control and G5 (p<0.05). Surface hardness in G5 was not significantly different from control (p=0.7) in enamel hardness test. There was not a significant difference between G2 & G3, G2 & G4, and G3 & G4 (p=1). The SEM results indicated globules of calcium fluoride on the surface in G2, and a smooth glaze-like surface layer in G3 and G4. In G5, some micro-cracks without any glaze-like layer were observed. Conclusions: APF, TiF4 and TiF4 before CO2 laser irradiation significantly increased the microhardness of initially demineralized enamel surfaces. CO2 laser irradiation before TiF4 application could not remineralize the white-spot lesions.
Background and Objectives: Autogenous gingival grafts are considered the “gold standard” for gingival augmentation, however they require a second surgical site for graft harvesting. Apically positioned flaps (APFs) represent an alternative method in soft tissue augmentation procedures. Limited information is available relative to the effectiveness of laser-mediated APF in augmenting keratinized gingiva (KG). The aim of this paper is to evaluate soft tissues changes following APF using CO2 laser in mandibular incisors with minimal KG and high labial frenum attachment. Materials and Methods: A total of 20 patients with minimal amount of KG (< 2 mm) on the labial aspect of one mandibular incisor and high buccal frenum insertion were selected for treatment. Only 19 completed the last follow-up visit. An APF consisting of a single superficial horizontal incision just coronal to the mucogingival junction using CO2 laser, elevation of a split-thickness flap, and suturing of the flap to the periosteum in an apical position was performed. The apico-coronal height of KG was measured at baseline, and at 3, 6 and 12 months postoperatively. Results: Uneventful healing was observed in all patients and an increase in KG of 2-3 mm was obtained. Most patients rated the procedure and the postoperative course as non painful. Conclusions: CO2 laser-assisted APF procedure is a minimally invasive treatment modality associated with reduced risk of bleeding and predictable increase in the height of KG.
Background and Aims: A paradigm shift towards noninvasive body contouring has occurred over the past few years. Radiofrequency (RF) is one popular treatment method. Noncontact-type RF systems with frequencies in the tens of megahertz represent a novel approach. The current pilot study investigated the efficacy of an interesting combination of extracorporeal shock wave therapy (ESWT) and an apoptosis-inducing RF (AiRF) system for circumferential reduction. Subjects and Methods: Twenty-seven females, ages ranging from 13-69 years, (mean age 37.96 years) participated in the study. They were assigned to two treatment-based groups: Group A (n=19) and Group B (n=8). A voluntary daily dietary restriction plan of 500 kcal was put in place for all subjects. A combination of two different devices was used; an extracorporeal shock wave therapy (ESWT) system and a 27.12 MHz AiRF system. Either 4 (n=28) or 6 sessions (n=19) were given, one week apart. In Group A, the ESWT was applied before the RF with the reverse order of application in Group B. Weight and waist circumference were noted at baseline, then one week after the 4th and the 6th treatment sessions at which points clinical photography was also obtained. Results: All patients showed statistically significant waist circumferential loss in both the 4- and 6-week treated groups: Group A, 6.3 cm and 8.8 cm; Group B, 5.9 cm and 6.4 cm, respectively. Greater circumference loss tended to be seen in Group A in both groups, but without statistical significance. No patient complained of pain during or after the treatment sessions, and there were no adverse events. Conclusions: This pilot study showed that the combination of ESWT and AiRF was safe and effective for significant waist circumferential reduction. The results tended to be better when ESWT was applied before AiRF, although the difference was not significant.
Background and Aim: Minocycline therapy for acne vulgaris is associated with the occasional induction of various types of unsightly and often persistent hyperpigmentation, which is frequently resistant to hydroquinone treatment. Pigment-specific lasers have achieved some success with multiple treatment sessions. Recently, the picosecond domain 755 nm alexandrite laser (ps-Alex) has attracted attention in tattoo removal. The present study reports on the successful treatment, in a single ps-Alex session, of minocycline-associated pigmentation. Subject and method: Subsequent to a course of minocycline, a 28-year-old Asian female developed persistent type 2 minocycline-related pigmentation on the bilateral lower extremities which was recalcitrant to hydroquinone treatment. The patient had a test treatment on a small area with a Q-switched ruby laser and the ps-Alex, following which the ps-Alex was selected for the actual treatment (spot size, 2 mm; fluence, 6.37 J/cm²; pulsewidth, 750 ps) on one leg first, followed later by the contralateral leg. Results: Rapid clearance of the pigmentation was noted after a single ps-Alex session on both limbs without prolonged post-inflammatory hyperpigmentation (PIH). At one year post-treatment, clearance had been maintained. Conclusions: Our results in this single case strongly suggest that the novel 755-nm ps-Alex laser is both safe and very effective for the treatment of type 2 minocycline-induced hyperpigmentation even in PIH-prone type IV Asian skin. Further trials with larger patient populations are warranted to confirm this optimistic result.