***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Aqueous hydrogen peroxide ( H2O2 ) has been used clinical ly at 30 % to 35 % levels to lighten teeth for many years , but the process has required multiple visits . Heat and light have been used empirically in attempts to catalyze H2O2 decomposition and speed tooth lightening . The contribution of bleaching lights ( LumaArch , Optilux 500 , and Zoom ! ) to act as catalysts for lightening teeth was studied in 83 pairs of contralateral anterior maxillary and m and ibular teeth on 15 human subjects . Split-arch design using central s , laterals , and canines on one side treated with bleach plus light , were compared with contralateral teeth using bleach alone . Three research ers trained in the use of the Vitapan 3D-Master Shade Guide took shades with independently agreement within 0.5 value-chroma sum 89 % of the time throughout the study Laboratory tests determined bleach gel chemistry , bleach light output , and effects on the bleaches of light alone and heat alone . Results showed that the three test lights did not lighten teeth more than their bleach gels alone . All teeth lightened to nearly the same degree ( 1.7 color increments ) , but LumaArch required 60 % less time and Zoom ! used 1/3 lower H2O2 concentration . Laboratory tests indicated that the proprietary chemicals mixed into each bleach gel just before use acted as catalysts and were probably responsible for more rapid lightening produced by LumaArch gel , and need for less H2O2 in Zoom ! gel . Neither the heat produced by the accessory lights , nor the light output itself were responsible for catalytic activity with any of the three systems tested . Collectively , the data demonstrate positive effects from chemical catalysts added to bleaching gels . No output from any of the lights result ed in heat or light that catalyzed the gels This study clinical ly evaluated the alteration of color , color stability , dental sensitivity and gingival irritation on patients undergoing dental bleaching using varying bleaching methods and light-activation sources . According to pre-established criteria , 40 patients were selected and r and omly divided into four groups ( n=10 ) : Group 1 - -35 % Hydrogen Peroxide ( HP ) ; Group 2 - -35 % HP plus Halogen Curing Light XL 3000 ( 3M/ESPE ) ; Group 3 - -35 % HP plus Demetron LED ( Kerr ) and Group 4 - -35 % HP plus LED/LASER ( Bio-art ) . For all groups , there were two sessions of bleaching with 35 % HP , with a one week break between sessions . At each bleaching session , three applications of the bleaching gel were used . Two methods of shade evaluation were performed before and after the first week , second week , first month and after six months of the bleaching treatment . These methods were VITA Easyshade Spectrophotometer and Vita Classical Shade Guide . Statistical analysis using ANOVA demonstrated e quality between the participating groups when evaluating the group and time variables . The In-Office dental bleaching treatments of vital teeth with 35 % HP did not prove to be more effective when light sources were used . There was no difference in color stability between groups until the sixth month of evaluation PURPOSE To compare in vitro the bleaching effects obtained with and without the use of the various lights on power bleaching systems . METHODS 19 groups of five tooth specimens were prepared and allocated r and omly to treatments . Only specimens with shade C4 were accepted for the study . Three commercial bleaching products all based on 35 % hydrogen peroxide were used with and without four different light sources . Shade assessment s were made using a Shade Guide ( SG ) , Shade Vision System ( SVS ) and chromometer . RESULTS For SG , all but the light only treatment result ed in measurable improvement in shade ranging from 4.6 to 14.6 shade guide units . Similar findings were apparent with SVS and chromometer . No change was seen in the light only treatments by SVS or SG with very small changes by chromometer . In mean terms with all three gels , least change was noted when there was no light used . For SG , SVS and chromometer data analysis over all treatment groups , excluding light only treatments , revealed highly significant differences . Within bleach product treatment differences were only significant with one gel both with and without light activation . Differences between gels with the same light and no light revealed some significant differences in SG and chromometer data but not SVS . In mean terms the order of efficacy of gels with each light and no light was the same for the majority of data sets BACKGROUND Light-activated bleaching is a method of tooth whitening . The authors conducted a study to compare the whitening effects and tooth temperature changes induced by various combinations of peroxide bleaches and light sources . METHODS The authors r and omly assigned 250 extracted human teeth halves into experimental groups ( n = 10 ) . A placebo gel ( control ) , a 35 percent hydrogen peroxide or a 10 percent carbamide peroxide bleach was placed on the tooth surface and was irradiated with no light ( control ) ; a halogen curing light ; an infrared , or IR , light ; an argon laser ; or a carbon dioxide , or CO2 , laser .  Color changes were evaluated immediately , one day and one week after treatment using a value-oriented shade guide and an electronic dental color analyzer . The outer enamel and inner dentin surface temperatures were monitored before and immediately after each 30-second application of light using a thermocouple thermometer . RESULTS Color and temperature changes were significantly affected by an interaction of the bleach and light variables . The application of lights significantly improved the whitening efficacy of some bleach material s , but it caused significant temperature increases in the outer and inner tooth surfaces . The IR and CO2 laser lights caused the highest tooth temperature increases . CONCLUSIONS Dentists performing an in-office bleaching technique with the use of an additional light source to accelerate tooth whitening should consider the specific bleaching agent being used , as well as the potential risks of heating teeth . CLINICAL IMPLICATION S A specific combination of bleach and light that demonstrates good color change and little temperature rise should be selected for in-office tooth bleaching OBJECTIVE Evaluate a light-enhanced in-office tooth whitening system in order to assess tooth color and safety . METHODS Thirty-three adults were r and omly assigned to one of three treatment groups . Professional treatment involved application of a 25 % H(2)O(2 ) gel ( Discus Dental ZOOM ! ) with light enhancement , H(2)O(2 ) gel alone , or the light alone with no peroxide . The 12 anterior teeth were treated three times for 20 minutes each . Efficacy was measured objective ly as L*a*b * color change using digital images , tooth shade was measured , and safety was evaluated immediately after treatment and at posttreatment days 7 and 30 . RESULTS After adjusting for baseline and age , immediate ( end-of-treatment ) means ( SE ) for Deltab * ( yellowness ) were -3.1 ( 0.25 ) for the gel + light , -2.0 ( 0.25 ) for the gel-only group , and -2.4 ( 0.25 ) for the light-only group . Significant ( p < 0.05 ) color rebound was evident at posttreatment day 7 . By day 30 , adjusted means (SE)for Deltab * were -1.7 ( 0.20 ) for the gel + light group , -1.1 ( 0.20 ) for the gel-only group , and -0.5 ( 0.20 ) for the light-only group . Both peroxide groups differed significantly ( p < 0.05 ) from light alone on Deltab * and DeltaL*. In the gel + light group , 91 % of subjects experienced tooth sensitivity , the majority of which was moderate or severe . Adverse events were low in the light-only group . CONCLUSION Use of light enhancement for in-office whitening leads to immediate color change , after which there was significant color and shade rebound within 7 days as well as moderate-to-severe tooth sensitivity during and after treatment . CLINICAL SIGNIFICANCE Increased tooth sensitivity during treatment and appreciable short-term color rebound after treatment may impact the utility of in-office tooth whitening with peroxide and light as a st and -alone esthetic procedure . ( J Esthet Restor Dent 21:336 - 347 , 2009 ) The objective of the present study was to assess the clinical efficacy of a dental bleaching system based on hydrogen peroxide with or without light activation . This r and omized controlled trial evaluated the effect of the light when applied to the hydrogen peroxide by using a split-mouth design with 21 patients , with light activation in one hemi-arch but not in the other . The bleaching agent was QuickWhite 35 % hydrogen peroxide and activation was conducted with a diode lamp ( Luma Cool ) . The Classic Vita Guide was used to score tooth shades . Two consecutive applications of hydrogen peroxide were made to one hemi-arch , each light-activated for 10 min . The other hemi-arch was then identically treated but without light activation . After removal of the bleaching agent , the shade was re-scored and the Wilcoxon signed ranks test was used to compare differences in tooth shade values . The bleaching treatment produced significant shade changes ( P < 0.01 ) in both hemi-arches . After treatment , there were no statistically significant differences between light-treated and non-light-treated tooth types ( central incisors , lateral incisors , and canines ) . However , taking central incisor , lateral incisor , and canine as a group , comparison between each hemi-arch showed a significant effect in the hemi-arch with light activation ( P < 0.05 ) . The use of diode light with a 35 % hydrogen peroxide gel slightly improved the dental bleaching The aim of this clinical study was to evaluate the efficiency of in-office bleaching systems with different light sources for color change and possible side effects such as tooth sensitivity and gingival irritations .  Forty healthy volunteers aged 18 years and older ( average age 27.3 years ) , having all their natural healthy teeth in shade A3 or darker on the Vita shade guide , with no restorations on the buccal surfaces and no tooth sensitivity , participated in this study . Participants were r and omly assigned to four groups of ten volunteers . Group 1 received bleaching without light activation ( Opalescence Xtra Boost , Ultradent ) ; group 2 received bleaching ( Laser White 10 , Biolase ) with a diode laser ( 810 nm , 10 W/ Laser Smile , Biolase ) activation ; group 3 received bleaching treatment ( Remewhite , Remedent ) with a plasma arc lamp ( 400–490 nm , 2800 mV/cm2 , Remecure CL15 ) , and group 4 received bleaching with a light emitting diode ( LED ) lamp ( By White accelerator , Ensodent ) according to the manufacturers ’ recommendations . The shade was assessed with a classical Vita shade guide ( Vita Zahnfabrik ) and a digital spectrophotometer ( Vita Easy Shade , Vident ) . The color of teeth was scored at baseline and 1 week after bleaching . Any side effects on teeth or gingiva was recorded by visual analog scale . Results were analyzed statistically , by one-way analysis of variance ( ANOVA ) , Kruskal – Wallis , and Mann – Whitney U tests with Bonferroni correction . All the bleaching techniques result ed in shade change . No significant differences were found in the color change among the four groups with shade guide assessment ( P > 0.05 ) , but spectrophotometer readings exhibited significant differences among the groups ( P < 0.05 ) . The overall shade change values expressed as ΔL , Δa , Δb , ΔE for group 2 was significantly higher than those for the other groups ( P < 0.05 ) . Group 2 also showed lower tooth and gingival sensitivity scores than those of the other groups ( P < 0.05 ) . All techniques result ed in shade change . Although the shade guide evaluation did not exhibit any differences among the bleaching treatment groups , spectrophotometer readings showed different findings . The results obtained by the two methods of evaluation of shade change used in this study were different from each other . Bleaching with diode laser result ed in less tooth and gingival sensitivity than the other bleaching systems . Clinical relevance : in-office bleaching systems used with or without light , lead to a shade change . As bleaching with diode laser result ed in less tooth and gingival sensitivity , it might be preferred among in-office bleaching systems AIM The study aim ed to evaluate the effect of four in-office dental bleaching methods on shade change , color stability , patient satisfaction and postoperative sensitivity . METHODS AND MATERIAL S Forty patients were r and omly divided into four groups ( n=10 ) according to the method of in-office bleaching  used : Group A-35 % hydrogen peroxide ( HP ) ; Group B-35 % HP plus BriteSmile and a blue curing light ; Group C-35 % HP plus QuickSmile and an LED curing light ; Group D-35 % HP and a Zoom2 metal halide curing light . For all groups , there was only one session of bleaching with three 20-minute applications of bleaching gel . The shade was evaluated before bleaching , immediately after , and one month after treatment using a VITA Classical Shade Guide . RESULTS Immediately after bleaching there was a significant difference in color change between the four groups , with Group B having the best results . At one month there was no difference between the four groups . Immediate postoperative sensitivity was the least in Group A and the highest for Group B. Patients in Group B were the most satisfied with the outcome of the bleaching procedure . CONCLUSIONS In general , the use of different lights for activation of an in-office bleaching agent did not affect the long-term results . Tooth sensitivity was mild and transient in the study . Patients were satisfied with in-office bleaching . CLINICAL SIGNIFICANCE Using light activation with in-office ble 
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After combining the four components and assessing the grade of the evidence , the strength of recommendation of the intervention is established .
This expansion of the GRADE ( Ex- GRADE ) permits the creation of a new instrument that can produce tangible data and possibly bridge the gap between evidence -based research and evidence -based clinical practice