***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: INTRODUCTION Various methods and material s are used in the treatment of dentin hypersensitivity . The aim of this r and omized prospect i ve controlled clinical trial was to evaluate and compare the desensitizing effects of the neodymium-doped yttrium aluminium garnet ( Nd : YAG ) laser and fluoride varnish by considering the degree of pre- and posttreatment pain , discomfort , and functional complications . METHODS Twenty patients with clinical ly diagnosed cervical dentin hypersensitive teeth were included and r and omly allocated to either the application of fluoride varnish ( group fluoride ) or Nd : YAG laser ( 100 mJ , 20 Hz ; group Nd : YAG ) . The assessment of pain and discomfort was performed by a visual analog scale after an air blast at baseline , immediately after treatment , and at patient visits on weeks 1 , 2 , 3 , and 4 . RESULTS Laser treatment result ed in significant improvements of discomfort immediately after treatment and after 1 week . At the 2- , 3- , and 4-week examination , the discomfort in group fluoride decreased up to nearly 75 % to 85 % of baseline scores , whereas the effect of the laser stayed nearly unchanged . The visual analog scale scores for pain at 4 weeks examination were significantly lower in the fluoride group compared with those in the laser group ( p < 0.05 ) . CONCLUSIONS Nd : YAG laser is a suitable tool for the immediately successful reduction of dentinal hypersensitivity and has better patient satisfaction and shorter treatment time Sixty adult patients were examined for dentin hypersensitivity prior to periodontal surgery .  Stimuli used included mechanical , cold water and compressed air blasts . A subjective assessment of the degree of hypersensitivity for each stimulus was recorded . This presurgical examination revealed 249 hypersensitive areas among 60 subjects . Following surgery there was over a 100 % increase in the pain ( hypersensitivity ) score . Desensitization with a 10 % strontium chloride hexahydrate dentifrice was begun 1 week after surgical treatment . After 7 weeks of dentifrice use the pain score was reduced 75.5 % in the test group . This was a reduction to a point below the preoperative level . The placebo group showed a reduction of 34.2 % which was still above the preoperative level . These results agree with other clinical studies that have demonstrated a desensitizing effect of strontium chloride OBJECTIVE The aim of the present study was to evaluate and compare the efficacy of CO(2 ) and Er : YAG lasers alone and in combination with topical sodium fluoride ( NaF ) in the management of dentine hypersensitivity .  MATERIAL S AND METHODS A group of 50 patients presenting with a total of 420 hypersensitive teeth were r and omly allocated into five groups . Group 1 was treated with 2 % NaF , groups 2 and 3 were lased by a CO(2 ) ( 1 W , continuous wave mode , for 10 sec ) or Er : YAG ( 30 Hz , 60 mJ for 10 sec , without water/air spray ) laser , and groups 4 and 5 received NaF plus the CO(2 ) and the Er : YAG laser , respectively . The scanning speed of the laser was 0.8 mm/sec . The degree of thermal sensitivity was determined with an evaporative stimulus consisting of a 1-sec air blast at a distance of 2 mm from each site tested . Quantification of the degree of discomfort was determined according to a four-point pain scale before treatment and 1 wk , 1 mo , and 6 mo after treatment . RESULTS All treatment forms result ed in significant improvement of discomfort . At 1 wk , 1 mo , and 6 mo , cold air blast scores were significantly reduced compared to baseline scores , except for the NaF group . In the NaF group , there was a statistically significant increase in mean degree of discomfort at 6 mo compared with 1 wk ( p + /- 0.01 ) and 1 mo ( p + /- 0.001 ) . Comparison of the other treatment regimens revealed that cold air blast scores were significantly lower for the other four treatments than for NaF gel alone ( p + /- 0.001 ) . No superiority was found for desensitization among the CO(2 ) , Er : YAG , CO(2 ) + NaF , and Er : YAG + NaF groups . CONCLUSIONS We concluded that both the CO(2 ) and Er : YAG lasers have promising potential for the treatment of dentine hypersensitivity . Lasers in combination with NaF gel appear to show better efficacy compared to either treatment modality alone OBJECTIVE To compare the clinical efficacy of the GaAlAs laser and dentin bonding agent in treating dentin hypersensitivity . METHODS One hundred and forty teeth from 70 patients diagnosed with dentin hypersensitivity , were divided into two groups : In group I , teeth were irradiated with 30 mW GaAlAs laser for 1 min and in group II , teeth were applied with dentin bonding agent . Sensitivity was assessed by tactile and thermal tests , measured with the criteria proposed by Uchida at baseline and after treatment ; immediately , at 15 and at 30 days . RESULTS The reduction of dentin hypersensitivity was observed in both treatments using the GaAlAs laser and dentin bonding agent . However , a greater reduction was observed over time up to day 15 and no significant change was observed between days 15 and 30 . Statistically significant differences in the level of dentin hypersensitivity between bonding agent and the GaAlAs laser were found at each observation period ( p < 0.05 ) . CONCLUSION The GaAlAs laser had less desensitizing efficacy compared with dentin bonding agent . However , the desensitizing effect of the GaAlAs laser still could be considered an effective therapy for treating dentin hypersensitivity Our previous in vitro study indicated that Nd : YAG laser irradiation on dentin could melt normal dentin surface and close the exposed dentinal tubule orifices without creating surface cracks . This study evaluated the morphologic changes of hypersensitive dentin after Nd : YAG laser irradiation .  Thirty patients with clinical ly diagnosed cervical dentin hypersensitive teeth were treated with a Nd : YAG laser of 30 mJ intensity at 10 pulses per second for 2 min . An impression of the sensitive area was taken before and after laser treatment and then examined with a scanning electron microscope . The impression of the dentin surface after Nd : YAG laser treatment showed no protrusive rods , in contrast with the presence of numerous rods before laser irradiation . Because protrusive rods are a measure of open dentinal tubules , we interpret these data to support the hypothesis that Nd : YAG laser irradiation at specifications of 30 mJ , 10 pulses per second , and 2 min can be used to seal the exposed dentinal tubules Clinical trials on dentine hypersensitivity have been numerous and protocol s varied . To date there is little consensus as to the conduct of studies on this poorly-understood yet common and painful dental condition . A committee of interested persons from academia and industry was convened to discuss the subject of clinical trials on dentine hypersensitivity and a consensus report is presented . A double-blind r and omized parallel groups design is recommended , although cross-over design s may be used for the preliminary screening of agents . Subjects may have multiple sites scored . Sample size will be determined by estimating the variability in the study population , the effect to be detected and the power of the statistical test to be used . Subject selection is based on a clinical diagnosis of dentine hypersensitivity , excluding those with conflicting characteristics such as currently-active medical or dental therapy . The vestibular surfaces of incisors , cuspids and bicuspids are preferred as sites to be tested . A range of sensitivity levels should be included . Tactile , cold and evaporative air stimuli should be applied . Negative and benchmark controls should be incorporated . Most trials should last 8 weeks . Sensitivity may be assessed either in terms of the stimulus intensity required to evoke pain or the subjective evaluation of pain produced by a stimulus using a visual analog or other appropriate scale . The subject 's overall assessment may be determined by question naire . Outcomes should be expressed in terms of clinical ly significant changes in symptoms . Follow-up evaluation is required to determine the persistence of changes . At least 2 independent trials should be conducted before a product receives approval Various methods and material s used in the treatment of dentin hypersensitivity are thought to achieve a therapeutic benefit by tubule occlusion . The aim of the present study was to evaluate the combined occluding effect of sodium fluoride varnish and Nd : YAG laser irradiation on human dentinal tubules . Thirty-six dentin specimens with exposed dentinal tubule orifices were used in this study . The sample s were r and omly divided into four groups . Groups A , B , and C were varnished by sodium fluoride , whereas group D served as a control . Then , group C was lased by 30 mJ of Nd : YAG laser , 10 pulses/s for 2 min by light painting . Three hours later , groups B and C were brushed by an electrical toothbrush for 30 min . Under SEM observation , the control group showed numerous exposed dentinal tubule orifices , and the sodium fluoride varnished specimens showed closure of exposed dentinal tubule orifices . After electrical toothbrushing , most of the sodium fluoride varnish was brushed away , except in the specimens that were irradiated by Nd : YAG laser . Over 90 % of the dentinal tubule orifices were occluded by sodium fluoride varnish combined with Nd : YAG laser irradiation OBJECTIVES This study evaluated the immediate and 3 month clinical effects of a low-level gallium-aluminum-arsenide ( GaAlAs ) laser and a 3 % potassium oxalate gel for the treatment of dentinal hypersensitivity . MATERIAL S AND METHODS A total of 164 teeth from 30 patients with clinical diagnoses of dentinal hypersensitivity were selected for this r and omized , placebo-controlled , double-blind clinical study . The teeth were r and omized to three groups : GaAlAs laser , oxalate gel , and placebo gel . The treatment sessions were performed at 7 d intervals for four consecutive weeks . The degree of sensitivity in response to an air blast and tactile stimuli was assessed according to a visual analogue scale at baseline , immediately after the fourth application , and then 3 months after the fourth application . The reductions in dentinal hypersensitivity from baseline at the two follow-up assessment s were evaluated as the main outcome . RESULTS In both the active and control groups , there were statistically significant reductions in dentinal hypersensitivity immediately after and 3 months after the treatments , when compared with the hypersensitivity at baseline . No significant differences among the three groups could be detected in their efficacy at either the immediate or 3 month evaluations irrespective of the stimulus . CONCLUSIONS The treatments under study were effective for reducing dentinal hypersensitivity , and longer observational periods could enhance the ability of studies to detect differences between active and placebo groups Dentine hypersensitivity has of long been known to be a common clinical problem in dental practice s. Lasers have recently come to play a prominent role in the treatment of this disorder . They might , however , cause dental pulp damage . This study was conducted to evaluate the effect of Nd : yttrium – aluminum – garnet ( YAG ) laser on partial oxygen saturation of pulpal blood in sensitive anterior teeth . In this clinical trial , 65 hypersensitive teeth were selected and r and omly allocated to two groups . The study group involved Nd : YAG laser treatment , while no treatment was employed for the control group . Using a pulse oximetry system , evaluations were preformed of the partial oxygen saturation in the pulpal blood before , immediately after , 1 week after , and 1 month after the treatment . The results were analyzed using the SPSS software and repeated- measures analysis of variance and paired- sample s t tests . The mean partial oxygen saturation of the blood was found to be 85.4 % in the study group , which was not significantly different from that of the control group . No significant differences were observed in the control group between the means obtained from pretreatment and post-treatment intervals ( P > 0.05 ) . The Post-treatment partial oxygen saturation mean rose to 89.3 % ( P = 0.001 ) and remained constant throughout the following week after it . However , no significant differences were found between the pretreatment partial oxygen saturation mean and the same measurement 1 month after treatment ( P = 0.702 ) . Nd : YAG laser therapy for dentine desensitization of anterior teeth caused no persistent changes in the partial oxygen saturation of pulpal blood . It may , therefore , be concluded that the diffusion of heat induced by the Nd : YAG laser into the pulp within the limit of the desensitization parameters cause no irreversible damages in the dental pulp BACKGROUND , AIMS Promising results using Nd : YAG laser against  dentin hypersensitivity  have been reported . The aim of this double-blind , controlled , split-mouth design ed clinical trial was to assess the effect of a single Nd : YAG laser application on alleviating hypersensitivity . METHODS / RESULTS Seventeen subjects participated in the study . Each of them had two teeth treated ; one with the laser activated and one with nonactivated ( placebo ) , for 2 min The assessment of pain was performed by a  VAS  , after an air blast at baseline immediately after treatment , at 1 week , 4 weeks and 16 weeks . Mean values of VAS for test and control teeth were compared by paired t-test ( alpha = 0.05 ) . The results showed mean baseline VAS values of 6.59 ( + /- 1.65 ) and 6.14(+/- 1.95 ) for test and control teeth , respectively 
    Output:
    
The remaining studies involved Nd : YAG laser , Er : YAG laser and CO2 laser , and all showed that the three types of lasers were superior to topical desensitising agents , but the superiority was slight .
A systematic review of the literature indicates the likelihood that laser therapy has a slight clinical advantage over topical medicaments in the treatment of dentine hypersensitivity .