Power Bleaching Research Articles

Effectiveness of KTP lasers in tooth bleaching, by comparing tooth color change after bleaching with KTP, Nd:YAG, Er:YAG, and diode laser system: A systematic review.

This systematic review evaluated the role of Potassium-titanyl-phosphate (KTP) lasers in dental bleaching by comparing tooth color change and rise in intrapulpal temperature after bleaching with KTP, Neodymium-doped yttrium aluminum garnet (Nd:YAG), Er:YAG, and diode laser system. Following were the inclusion criteria: in vitro studies in English available in full text. Articles published between 2000 and 2021 were selected. The search for was conducted on PubMed, Cochrane library/CENTRAL, Wiley online library, ProQuest, Science Direct, and Hand searching/specialized registers. Keywords were used: "Lasers" [Mesh] and "Tooth bleaching" [Mesh] using Boolean operators. A total of four articles fulfilled the inclusion criteria. The quality assessment of studies included was undertaken independently as part of data extraction process. KTP lasers demonstrated more effectiveness in attaining color change in stained teeth and showed the lowest rise in intrapulpal temperature. Based on the data obtained in the present review, the choice of bleaching treatment is directly related to the type of discoloration, activation of the bleaching agent, and esthetic requirement. Although all bleaching procedures were effective in color change, the KTP laser showed better results when compared to other laser activation. The bleaching treatment protocol is directly related to the type of discoloration, activation of the bleaching agent, and esthetic requirement. It has been demonstrated that a faster change in color can be obtained when bleaching is performed in combination with a light source, i.e., power bleaching aiming for a more in-depth change of color.

In-Office Power Bleaching for the Aesthetic Management of Dental Fluorosis

In-Office Power Bleaching for the Aesthetic Management of Dental Fluorosis

Effects of Different Light-Assisted Power Bleaching Techniques on the Penetration of Hydrogen Peroxide into the Pulp Chamber.

Background: In-office bleaching is one of the most commonly used procedures for discolored tooth treatment. Although the efficacy of tooth bleaching has been investigated, depending on the applied technique and the used materials, bleaching procedures might irritate the tooth pulp and induce surface changes in enamel. The aim of this study was to evaluate the effect of four different bleaching techniques on the penetration of hydrogen peroxide (HP) into the pulp chamber. Materials and methods: Seventy-two single-rooted sound human teeth were used. The samples were prepared and evaluated in four groups. Group 1: 35% HP gel alone (HP Gel); group 2: Nd:YAG laser (0.25 W and 10 Hz with a fiber tip size of 200 μm) irradiation was added (HP Gel+laser); group 3: HP gel mixed with graphite particles (10th of millimeter in size) derived from crashed pencil lead in association with Nd:YAG laser (HP Gel+laser+graphite); and group 4: HP gel in association with light-emitting diode (LED) (litex 686, 50 Hz, 450-490 nm) (HP Gel+LED). The amount of HP penetrating into the pulp chamber was evaluated using acetate buffer and standard graphs. Data were analyzed with one-way ANOVA test, using SPSS 17. Post hoc Tukey test was used for between-group comparisons (α = 0.05). Results: Statistical analyses showed that the HP Gel+laser+graphite group had significantly higher level of HP penetration than other groups (p < 0.001). Moreover, pulp chamber penetration of HP in the HP Gel+laser group was greater than the LED and control groups (p < 0.001). The difference between control and LED groups was not significant (p = 0.99). Conclusions: Laser bleaching associated with HP Gel and graphite particles resulted in increased penetration of HP into the pulp chamber compared with the LED and control groups.

Dental Fluorosis Management Using Power Bleach – A Magic Wand

Dental fluorosis is a particular condition brought on by long-term, excessive fluoride consumption during the formation of enamel. Fluorosis staining is frequently seen as an aesthetic problem may have psychological effect of when seen on maxillary anterior teeth. Bleaching, microabrasion, veneering, and crowning are some of the treatment options. Bleaching is a conservative approach of restoring the colour of teeth with intrinsic discolouration. Among the various bleaching techniques, In-office or Power bleaching techniques are effective to obtain result immediately. The dentist is in complete control of the process throughout the treatment. It is a fast process and results are evident in single visit. Here we present a case of management of dental fluorosis using Power bleaching technique.

Effect of Different Bleaching Methods on Monomer Release from Aged Microhybrid and Nanohybrid Resin Composites.

Recently, the application of laser-assisted bleaching has increased in dental practice. This method might affect the physical and chemical properties of resin composite and its monomer release. This study aimed to evaluate the effect of in-office, at-home, and laser-assisted bleaching on the monomer release (bisphenol A diglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), and urethane dimethacrylate (UDMA)) from aged nanohybrid (Grandio, Voco) and microhybrid (Clearfil AP-X Esthetics, Kuraray) resin composites. Thirty-two samples of each composite were prepared. The samples underwent aging procedure with UV light at 65°C for 100 hr. The samples were divided into 4 groups: OB: conventional in-office bleaching with Opalescence Boost PF 40% gel; HB: home bleaching with Opalescence PF 15% gel; LB: bleaching with JW Power bleaching gel followed by diode laser application; and C: control group without bleaching. Then, the samples were immersed in a solution containing 75% ethanol + 25% distilled water. The medium was renewed after 8, 16, 24 hr, and 7 days and was analyzed using high-performance liquid chromatography method to evaluate the monomer release. The data were analyzed using Two-way ANOVA and Post hoc Tukey test. The bleaching method had no effect on TEGDMA and BisGMA release in both composites while it affected UDMA release in nanohybrid composite; UDMA release was significantly higher in LB compared to control and also higher in OB and LB compared to HB. No difference was observed in the microhybrid composite in this regard. Laser-assisted bleaching did not affect monomer release from microhybrid composite while it increased UDMA release from nanohybrid composite. The bleaching method had no effect on TEGDMA and BisGMA release.

Effect of Combining Minimal Invasive Modalities on Treating Mild Dental Fluorosis: An In vivo Study

BACKGROUND: Fluorosis is intrinsic tooth discoloration which compromises esthetics depending on its severity. AIM: The aim of the study was to assess the efficiency of various treatment modalities in esthetic improvement of mild fluorosed teeth. MATERIALS AND METHODS: Four patients with 48 mild fluorosed teeth were randomly assigned to four treatment modalities (n = 12). The modalities included M1: power bleaching, M2: microabrasion and power bleaching, M3: power bleaching and resin infiltration and M4: microabrasion, power bleaching and resin infiltration. Color parameters (L, a, b) and visible color change (ΔE) were measured by spectrophotometer (VITA Easyshade®) at baseline, immediately after the treatment, after 3, 6, and 9 months. STATISTICAL ANALYSIS: Two-way ANOVA was applied to test the interaction between different variables. ANOVA repeated measures were followed by Duncan multiple range tests (DMRTs) to compare between groups. RESULTS: All the treatment modalities showed significant color change (ΔE) at all-time points compared to baseline. The highest color change was recorded in the resin infiltration treatment modalities compared to the other treatment modalities. Bleaching alone had the lowest change. CONCLUSION: Resin infiltration treatment modalities were more effective in the esthetic improvement of dental fluorosis compared to either power bleaching alone or combination of microabrasion and power bleaching.

Microhardness change of human dental enamel due to power bleaching with different gels.

Since the introduction of bleaching treatments in the office, different lights have been suggested to accelerate the bleaching reaction. This study aimed to evaluate the microhardness of tooth enamel after office bleaching using different materials.

Application of nanotechnology for optimization of bleaching efficiency of edible oils

Nanotechnology is the recent science dealing with materials at the nano-sized (smaller than 100nm). Nanotechnology showed its potential significance in almost all industrial sectors. In the current paper, the potency of nanotechnology was affirmed in the food science and technology, especially in the manufacturing of edible oils which passes many procedures, from which is the most important step of bleaching edible oils to remove colorants and contaminants and enhance the quality parameters of these vital components of the human diet. Bleaching process made use of bleaching earth powder which was converted into the nano-sized and then utilized in the bleaching process of edible oils. Results showed the powerful bleaching efficiency optimized by applying nanotechnology in converting the bleaching earth powder to the nano-sized through mechanical milling processes which resulted in smaller size in nanoscale with more efficient surface area available for adsorption of colorants and contaminants of the edible oils resulting in pure edible oils of superior quality and safety.

Effect of conventional and power office bleaching with diode laser and led light on enamel microhardness

Aim: The present study aimed to asses enamel microhardness after office bleaching with diode laser and LED light compared to the conventional bleaching procedure. Methods: Thirty-nine human premolar teeth were collected and randomly divided into three groups regarding of the bleaching technique. Group 1: Snow O bleaching gel with LED light-curing unit; Group 2: Snow L bleaching gel with diode laser irradiation; and Group 3: Opalescence Boost bleaching gel with no light source in group 3. Enamel surface changes were evaluated in one tooth in each study group and one intact tooth as a reference under a scanning electron microscope (SEM). In the remaining samples (n=12), enamel microhardness was determined by Vickers microhardness test before and after bleaching. Data were analyzed with repeated-measures ANOVA to compare microhardness changes, followed by post hoc Tukey tests at the 0.05 significance level. Results: Enamel microhardness decreased in all the groups after bleaching, with the maximum decrease in microhardness in the Snow O bleaching group with LED light, which was significantly higher than the other groups (P=0.002). The two other groups did not exhibit any significant difference in microhardness decrease (P&gt;0.05). Conclusion: Based on the limitations of this study, it can be concluded power bleaching with 980nm diode laser was less time-consuming compare to conventional bleaching procedure and yielded better outcomes in terms of enamel surface microhardness compared to the use of an LED light-curing unit.

Efficacy of Nano Crystallised Calcium Phosphate (NCCP) and Casein Phosphopeptide – Amorphous Calcium Phosphate (CPP-ACP) for Controlling Postoperative Sensitivity After Power Bleaching-A Comparative In-Vivo Study

Tooth bleaching is one of the most popular cosmetic dental procedures opted by the patients who desire pleasing smile. It is the simplest, least invasive means available to lighten discolored vital teeth. A number of desensitizing agents have been tried in an attempt to counteract bleaching-related sensitivity. This study was done to compare the effect of two different desensitizing agents for controlling post operative sensitivity after power bleach procedure. Sixty volunteers with mild to moderate dental fluorosis in maxillary anterior teeth, who fulfilled the inclusion and exclusion criteria, were randomly selected for this study. After the bleaching procedurea demo was given to the patient while application of desensitising gel and was instructed to use the gel for 14 days.All the patients were recalled at an interval of 1st day, 3rdday, 5th day, 7th day, and on 14th day to record the post operative sensitivity after power bleach procedure. The observations were analyzed using one way analysis of variance (ANOVA), Tukeys post hoc test. On the basis of VAS results, all the groups showed post operative sensitivity of varied intensity at different intervals. NCCP showed less sensitivity followed by CPP-ACP and Control group.&#x0D; Keywords: Power Bleaching, Post operative sensitivity, Nano Crystallized Calcium Phosphate, Casein Phosphopeptide-Amorphous Calcium Phosphate

EFFICACY, TOOTH SURFACE MICROHARDNESS AND ROUGHNESS AFTER TREATMENT WITH COMBINATION OF LASER AND HOME BLEACHING PROTOCOL: AN IN VITRO STUDY

Teeth whitening or bleaching has pleased people with aesthetic concerns for long. To improve the efficacy of bleaching and reduce the ill effects on the tooth surface, a combination of power bleaching (PB) and home bleaching (HB) can be used. Objective. To compare the efficacy and effects of combinations of PB/laser bleaching (LB) and HB protocol on human natural tooth structure. Materials &amp;amp; methods: Eighty-eight permanent maxillary central incisors were randomly divided into four groups (n=22). After staining, teeth were bleached using different bleaching protocols: Group 0 (control), Group 1 (Laser White 20 46% hydrogen peroxide (HP) + Opalescence PF 20% carbamide peroxide (CP) – HB sequence for 3 days), Group 2 (Laser White 20 46% HP + Opalescence PF 20% CP – HB sequence for 7 days), Group 3 (Opalescence PF 20% CP – HB sequence for 14 days). Colorimetric measurement was performed, enamel surface roughness and microhardness were measured. Scanning Electron microscope (SEM) evaluation was done to compare the surface topography. Pre and post bleaching data were analysed using paired T-test. Multiple comparison between groups was carried out using one-way ANOVA complemented by Post hoc test (Bonferroni), with significance level set at P&amp;lt;0.05. Results: All protocols demonstrated significant efficacy to whiten stained enamel. All groups demonstrated significant increase in hardness (P&amp;lt;0.05). Surface roughness reduced significantly in Group 1 and 2. SEM showed that Group 1 had a similar microscopic surface appearance as unbleached enamel, while Group 3 had accentuated irregularities. Conclusion: LB followed by HB for 3 days is the most effective in whitening stained teeth with positive effects on tooth surface hardness while maintaining surface topography of dental hard tissues.

Comparison Between Color Stability and post bleaching hypersensitivity of Different Bleaching Protocols – Randomized single-blinded Controlled Clinical Trial

Objective: The aim of the study was to investigate color change, color stability and post bleaching hypersensitivity after performing 3 bleaching protocols, (LASER-activated, light-activated and chemically-activated) at different time intervals. Methods: Patients were randomly assigned into three treatment groups (n=13). Group A received laser bleaching (J.W. Power Bleaching NEXT, 35 % hydrogen peroxide), group B received light-activated bleaching (Philips ZOOM, 25% hydrogen peroxide), and group C received chemical activated bleaching Dash Philips, 30% hydrogen peroxide). Each group received the treatment according to the manufacturer’s recommendations, followed by the desensitizing agent of each kit. Outcome assessment was performed for teeth shade and post bleaching hypersensitivity preoperatively, immediate, three months, and six months post-operatively using a spectrophotometer (Vita Easyshade, Vivadent, Germany). Results: The study showed that there was no significant difference in color change between the three tested groups. LASER-activated bleaching protocol showed no significant difference in median ∆E throughout the study. Light activated bleaching showed decrease in median ∆E three to six months while in chemical-activated bleaching from zero to three months. Post-bleaching hypersensitivity, results showed no significant difference between the three tested groups. Conclusion: All three bleaching methods can be used upon individual’s preference. LASER-activated bleaching group showed superior color stability over time. It can be satisfactory for patients seeking good results with reduced chair time. Keywords: bleaching, post bleaching hypersensitivity, laser, color stability

A comparative analysis of in-office vital 6% hydrogen peroxide activated charcoal tooth whitening treatment enhanced with an 810nm diode laser, compared to 35% hydrogen peroxide bleaching

Laser dental bleaching is considered to be a contemporary approach to enhancing the in-office power bleaching procedure.&#x0D; Objective&#x0D; Investigate if laser enhanced 6% Hydrogen Peroxide (HP) solution is equivalent to 35% HP solution over a two-visit power bleaching treatment protocol. In a randomised double-blinded clinical trial, 43 patients were assigned to a group that received either the laser-enhanced 6% Hydrogen Peroxide (n=21) treatment, or the standard 35% Hydrogen Peroxide (n=22) treatment, over two visits, with a one-week interval. Activated charcoal HP paste was prepared for both groups. The laser enhanced 6% HP group received a dosage of 90 J/cm² per bleaching cycle using 810nm diode laser. Tooth colour was measured at the beginning and end of each session registering parameters L*, a* and b*, and tooth sensitivity. The calculated difference between these Parameters, ∆E, was the primary data focus. The mean ∆E over the treatment duration was used to answer the research question by a t-test to evaluate group differences at 5% significance level. The analysis revealed that the null hypothesis could not be rejected and the results were inconclusive. The observations expound the idea of an absorption enhancement mechanism, rather than a free radical activation, as the technique for improving bleaching outcomes.

Evaluation of Antioxidant Property of Amla on Bond Strength and Color Stability of Power Bleached Teeth: An In vitro Study.

Introduction:Objective: To assess the antioxidant property of 10% amla extract in reversing the compromised bond strength and to assess the antioxidant property of 10% amla extract and Elsenz on the color stability of power bleached teeth.Materials and Methods:Ninty extracted single-rooted maxillary anterior were collected and divided as follows: The labial surfaces of 30 samples were subjected to power bleaching after which the samples were divided into three groups– Group I (control), Group II (antioxidant amla), and Group III (Elsenz) with n = 10 in each which were then stained with a coffee solution for 10 mins. The color difference was recorded with a colorimeter at baseline, after bleaching, after 7, and after 15 days of staining. sixty specimens were randomly divided into six groups (n = 10) as following: Group I (immediate bonding); Group II (bleaching + immediate bonding); Group III (bleaching + antioxidant and immediate bonding); Group IV (bleaching + 1 week storage + antioxidant + bonding); Group V (bleaching + 2 week storage + antioxidant + bonding); Group VI (bleaching + 2 week storage + bonding). All the specimens were tested for shear bond strength in universal testing machine. Statistical analysis was performed using ANOVA and Scheffe's post hoc test.Results: Significantly higher staining was observed in Group II (amla) and least with Elsenz pasteThe highest mean shear bond strength was found in Group I followed by Group V. Conclusion:Elsenz showed the least staining followed by artificial saliva. 10% Amla extract neither was effective in preventing staining of power bleached enamel nor in restoring the poor bond strength of power bleached enamel.

An Environmental Scanning Electron Microscopy Evaluation on Comparison of Three Different Bleaching Agents using the Laser Activated in-Office Bleaching at Different Wavelengths.

Background:Shade of the teeth is of specific significance to the patient because of social and psychological concern and hence plays vital role as primary care. Bleaching is a noninvasive, relatively inexpensive, conservative, and low-maintenance method to change a smile dramatically.Aim:To study the effect of application of three bleaching agents at different wavelengths of laser on the enamel surface of teeth using an environmental scanning electron microscopy (ESEM).Materials and Methods:One hundred and twenty freshly extracted, noncarious intact maxillary central incisors were collected and stored in moist conditions in plastic containers. Using a randomized stratified design, the samples were divided into 12 groups (n = 10). The bleaching agent was mixed according to the manufacturer's instructions and applied on the enamel surface of the teeth followed by laser activation. The ultrastructural effects of the bleaching agent on the enamel were determined with an ESEM. Samples were assessed both before and after bleaching on the basis of the degree of surface damage. Because the observation by ESEM was designed to be qualitative, no statistical analysis was performed.Results:JW power bleaching agent and Opalescence Xtra boost showed minimum surface alteration when compared to Polaoffice. Furthermore, the groups treated with diode 810 nm showed less surface damage while neodymium-doped yttrium aluminum garnet 1064 nm more surface alterations than the groups treated with diodes.Conclusion:From this current study, it can be concluded that the diode laser of 810 nm with JW power bleaching showed minimum surface alterations.

Influência dos agentes clareadores com alta concentração de peróxidos sobre a rugosidade superficial de diferentes tipos de compósitos

This study aimed to evaluate the surface roughness of different types of composites after the application of two bleaching agents with high concentrations of peroxides. This study is an in vitro research that evaluated the microparticulate composite resin (Durafill, Heraeus-Kulzer), the microhybrid (Z250, 3M-ESPE), and nanohybrid composites (IPS Em press Direct, Ivoclar Vivadent), that were submitted to the action of 40% hydrogen peroxide (Opalescence Boost PF, Ultradent) and 37% carbamide peroxide (Power Bleaching Office 37%, BM4), simulating in-office dental bleaching. For this, 90 samples were made, 30 for each composite, divided into 9 groups (n = 10): G1, G4, and G7 did not receive any bleaching treatment (control groups); G2, G5, and G8 treated with 40% hydrogen peroxide; and G3, G6, and G9 treated with 37% carbamide peroxide. Each sample was submitted to avaliation of the superficial roughness with a rugosimeter. The data were submitted to statistical analysis using ANOVA and Tukey Test at a level of significance of 1%. There were statistically significant differences (p&lt;0.01) between the control groups and the experimental groups submitted to the use of both bleaching agents, for all composites. The microparticulate composite was the most affected material by the use of these peroxides. Thus, bleaching agents in high concentration were able to negatively affect, increasing the surface roughness value of the three types of composites tested, and care should be taken with their application on restorations made with these restorative materials.

IN VITRO ANTI-WRINKLE AND TYROSINASE INHIBITORY ACTIVITIES OF GRAPEFRUIT PEEL and STRAWBERRY EXTRACTS

The research aims to analyse the antioxidant, anti-tyrosinase and anti-wrinkle activities from grapefruit (Citrus Maxima L) and strawberry extracts. Samples were extracted by maceration using 96% ethanol and ethyl acetate, subsequently. The Ferric Reducing Antioxidant Power (FRAP) and β-carotene bleaching (BCB) were used to measure the antioxidant activity. The effect of anti-wrinkle was determined by testing the inhibition of elastase and collagenase enzyme, while anti-tyrosinase activity was analysed using mushroom tyrosinase enzyme. The results showed that strawberry extracts in ethanolic (SE) and ethyl acetate (SEA) have antioxidant activity in FRAP (EC50 = 404.39 ± 3.27 µg / mL and 1978.65 ± 37.25 µg/mL) and BCB (IC50 = 292.30 ± 4.69 µg/mL and 671.11 ± 6.74 µg/mL). Whereas the grapefruit peel extracts both in ethanolic (GPE) and ethyl acetate (GPEA) have antioxidant activity in FRAP (EC50 219.47 ± 71.96 µg / ml and 309.44 ± 95.76 µg/ml) and BCB (EC50 245.19 ± 162.47 µg/ml and 567.54 ± 95.31 µg/ml). As positive standards for FRAP antioxidant analysis were quercetin and vitamin C which has IC50 respectively 18.97 ± 4.50 µg/mL and 24.47 ± 1.44 µg/mL. While in BCB analysis, Butylated Hydroxy Toluene (BHT) used as positive standard (IC50 38.68 ± 5.70 µg/mL). The samples of SE, SEA, GPE and GPEA showed tyrosinase inhibitory activity which the IC50 values were respectively 492.68 ± 1.43; 2658 ± 48.08; 3312.5 ± 222.74; 2985.17 ± 122.80 µg/ml. Kojic acid (IC50 111.52 ± 0.42 µg/ml) is used as positive standard in this study. In addition, SE, SEA, GPE and GPEA were able to inhibit elastase and collagenase enzymes, although their activities were still lower than the positive standard used in this study. Elastastinal in concentration 50 µg/mL giving elastase inhibition about 71.71 ± 0.81 µg/mL, while vitamin C in the same concentration showed collagenase inhibition about 66.79 ± 1.23 µg/mL. It can be concluded that the extract of strawberry and grapefruit peel has antioxidant, anti-tyrosinase and anti-wrinkle activity through inhibition of elastase and collagenase enzymes; thus, they can be used as antiaging cosmetic ingredients.

Concordance of antioxidant and anti-Inflammatory activity in Xylocarpus granatum (Koen)

Xylocarpus granatum, a common mangrove plant is traditionally used for the treatment of diarrhoea, cholera, fever, dyslipidemia, inflammation, etc. The present study was carried out to evaluate the antioxidant and anti-inflammatory potential of the ethanolic extract of X. Granatum by various in vitro methods such as 1,1-diphenyl-2-picryl-hydrazil (DPPH) free radical scavenging assay, reducing power assay, ferric reducing antioxidant power (FRAP) and β-carotene bleaching inhibition assay. Total phenolic and flavonoid content were determined. Anti-inflammatory activity was evaluated by in vitro human RBC membrane stabilizing assay and in vivo mice paw edema test. Ethanolic leaf extract (S2) of X. granatum showed significant scavenging effect on DPPH scavenging with a value of IC50 165.95µg/ml. In addition, it showed significant reducing potential with a value of 59.04 mM of ferrous equivalent per ml in FRAP assay and in reducing power assay the EC50 value was determined as 241.61μg/ml . The ethanolic leaf extracts exhibited 72.3% β-carotene bleaching inhibition. The total phenolic and flavonoid content of the extract were 66μg/ml gallic acid equivalent and 47.66μg/ml quercetin equivalent per gram of dry extract, respectively. The extract also exhibited 52.63% and 51.05% protection of RBC membrane in hypotonicity and heat induced lysis inhibition, respectively. Significant reduction of mice paw edema (36.34% in 20 μg/kg bw concentration) was observed in the extract. The results revealed that the leaf extract of X. granatum possesses strong antioxidant and anti-inflammatory potential.&#x0D; &#x0D; J Bangladesh Agril Univ 17(4): 466–475, 2019

Screening of traditional Lebanese medicinal plants as antioxidants and inhibitors of key enzymes linked to type 2 diabetes

This study aimed to investigate the inhibitory activity of key enzymes linked to type 2 diabetes (α-amylase and α-glucosidase) and the antioxidant properties of non polar (n-hexane) extracts from Coffea arabica, Citrus lanatus, Cucumis melo, Cuminum cyminum, Cocos nucifera, Coriandrum sativum, Foeniculum vulgare, Nigella sativa, Rhus coriaria, Pimpinella anisum, Syzygium aromaticum and Sesamum indicum collected in Lebanon. Extracts were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was investigated by using different in vitro methods namely 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Ability Power (FRAP) and β-carotene bleaching tests. C. melo showed the highest α-glucosidase inhibitory activity with an IC50 value of 25.55 μg/ml, followed by C. lanatus white seeds and S. indicum (IC50 of 34.41 and 38.78 μg/ml, respectively). S. indicum exhibited also the highest protection of lipid peroxidation with IC50 values of 0.07 and 0.06 mg/ml after 30 and 60 min of incubation, respectively.

Clinical Investigation of 940 nm Diode Laser Power Bleaching: An In Vivo Study.

Introduction: The increased demand by patient to whiten their teeth in short time had made in-office bleaching procedure the common one. The accompanying tooth sensitivity remains an important factor affecting patients physically and psychologically. The aim of this in vivo study was to observe the effectiveness of 940 nm diode laser in combination with bleaching gel by analyzing tooth sensitivity and colour change. Methods: Fourteen patients treated by laser-assisted bleaching using diode laser at 940 nm and bleaching gel containing 38% hydrogen peroxide. Tooth sensitivity recorded during and after treatment at 6 hours and 1 day using visual analogue scale (VAS). Tooth shade had recorded before and after bleaching using Vita classical brightness scale. Results: Patients whom did not experienced pain during and after the treatment were 78.60% and 92.90%, respectively. Tooth brightness change after treatment was statistically different (P = 0.001). Conclusion: Diode laser of 940 nm is an effective adjunctive tool for reducing tooth sensitivity originated from high concentration H2 O2 bleaching gel.