Hypersensitive teeth. Experimental studies of dentinal desensitizing agents

The effect of dentinal desensitizing agents on nerve activity was tested. Effective agents such as KNO3 reduce dentinal sensory nerve activity. This effect is due to the depolarizing action of the K+ ion.     

聚酰胺-胺型树枝状分子对牙本质小管的封闭作用

目的 研究聚酰胺-胺型树枝状分子(polyamidoamine dendrimer,PAMAM)封闭牙本质小管的效果,为牙本质敏感的治疗提供实验依据.方法 选取7颗健康第三磨牙制备28个牙本质薄片,按随机数字表分为A、B、C、D、E、F、G7组,G组为空白对照组不作处理,A～E组经脱矿后置于含PAMAM的0.25％戊二醛水溶液中4℃24h,然后A～E组分别在再矿化液中矿化0、6、12、18和24h,F组脱矿后直接于再矿化液中矿化24h.用场发射扫描电子显微镜(field emission scanning electron microscope,FE-SEM)、X射线衍射(X-ray diffraction,XRD)和能量色散X射线分光计(energy dispersive X-ray spectrometer,EDXS)观察检测.结果 FE-SEM可见各组牙本质样本矿化程度不同,随矿化时间延长,样本表面矿化物逐渐形成,直至完全覆盖样本表面,矿化物可封闭牙本质小管达一定深度.矿化物经EDS和XRD检测证实为羟基磷灰石晶体.结论 PAMAM具有良好的牙本质小管封闭作用,在牙本质敏感的治疗方面有一定的潜在应用价值.     

铒激光不同参数对牙本质小管即刻封闭影响的实验研究

目的:比较不同工作参数下铒激光处理后牙本质小管封闭的效果,探求铒激光即刻封闭牙本质小管的最佳参数。方法:制备54个牙本质盘,0.5 mol/L EDTA脱矿形成敏感牙本质模型。以铒激光的输出功率、照射时间、照射距离为实验指标,设计正交优化实验表,样本随机分成9组,每组6个样本,铒激光照射后扫描电子显微镜观察,评估各组牙本质小管封闭情况。结果:脱矿组牙本质小管口开放,清晰可见,激光照射组牙本质小管表面有明显熔融物沉积,各组牙本质小管封闭率有显著性差异(P<0.05)。结论:铒激光照射对牙本质小管有一定封闭作用,且受工作参数影响。本实验条件下,照射距离影响最大,最佳工作参数组合是:距离2.0 cm,照射功率0.2 W,照射时间30 s。     

过氧化脲对牙本质小管通透性的影响及酪蛋白磷酸多肽-无定形磷酸钙的封闭作用

目的采用扫描电镜技术观察过氧化脲漂白剂（CP）对牙本质小管通透性的影响以及酪蛋白磷酸多肽一无定形磷酸钙（CPP—ACP）对漂白剂预处理后开放的牙本质小管的封闭作用。方法取未萌出的离体下颌第三磨牙,去除牙冠后制备成厚度为2mm的牙本质盘。在牙本质小管通透性试验中,按近远中向平均分为实验侧和对照侧,实验侧分别使用10％CP、35％CP和37％磷酸对牙本质横剖面进行处理,对照侧使用蒸馏水处理,应用扫描电镜技术观察牙本质小管通透性的差异。在牙本质小管封闭性试验中,实验组使用CPP—ACP对10％CP预处理的牙本质盘进行表面涂布,对照组使用抗过敏药物MScoat和ultraEz脱敏胶,在扫描电镜下观察牙本质小管的封闭情况。结果10％CP和35％CP处理后,实验侧牙本质小管开放的数目明显高于对照侧,实验侧的小管直径分别为（1．21±0．56）μm和（1．52±0．64）μm,均显著大于对照侧（0．50±0．27）μm．和（0．51±0．30）μm,P〈0．05;37％磷酸处理后实验侧小管直径为（2．20±0．48）μm,显著大于10％CP和35％CP处理组。CPP—ACP对10％CP预处理后开放的牙本质小管有一定的封闭作用。结论CP可促进牙本质小管开放,与漂白术后牙敏感有关;而CPP—ACP局部应用后具有封闭牙本质小管的作用,有助于减轻cP漂白所致的牙齿敏感。     

Effect of a desensitizing dentifrice on dentinal hypersensitivity

The objective of this study was to assess the effectiveness of a dentifrice with 2% dibasic sodium citrate in poloxamer 407 in decreasing dentinal hypersensitivity. The test toothpaste was compared with a control toothpaste containing 0.76% sodium monofluorophosphate in a 6-week double-blind clinical trial. A total of 75 hypersensitive teeth were examined in the test group, while 100 hypersensitive teeth were in the control group. Changes in hypersensitivity levels were monitored after 6 weeks, using thermal, chemical and mechanical stimuli. At the end of 6 weeks, the test dentifrice was not significantly more effective than the control in decreasing dentinal hypersensitivity. Of the stimuli used, cold was the most effective in eliciting a hypersensitive response, followed by chemical stimulation and air. Heat and toothbrushing caused the least discomfort.     

Effect of a desensitizing dentifrice on dentinal hypersensitivity

Abstract The objective of this study was to assess the effectiveness of a dentifrice with 2% dibasic sodium citrate in poloxamer 407 in decreasing dentinal hypersensitivity. The test toothpaste was compared with a control toothpaste containing 0.76% sodium monofluorophosphate in a 6-week double-blind clinical trial. A total of 75 hypersensitive teeth were examined in the test group, while 100 hypersensitive teeth were in the control group. Changes in hypersensitivity levels were monitored after 6 weeks, using thermal, chemical and mechanical stimuli. At the end of 6 weeks, the test dentifrice was not significantly more effective than the control in decreasing dentinal hypersensitivity. Of the stimuli used, cold was the most effective in eliciting a hypersensitive response, followed by chemical stimulation and air. Heat and toothbrushing caused the least discomfort.     

牙本质小管封闭治疗牙本质过敏症的机制和效果

牙本质过敏症是由于釉质的完整性受到破坏,造成牙本质小管暴露,从而使牙齿对温度、化学物质和机械刺激等因素敏感的一种临床病症。其治疗的主要方法是封闭暴露的牙本质小管,降低牙本质小管的通透性。封闭方法按机制可分为原位沉积法、氟诱导矿化法、纳米粒子填塞法、粘接覆盖法和激光熔融法等。对于这些封闭方法实验室常用的效果评价手段主要包括扫描电镜观察和牙本质渗透性检测。本文就近年来封闭牙本质小管不同方法的内在机制和效果作一综述。     

Effects of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention

This study aimed to compare the effect of precementation desensitizing laser treatment and conventional desensitizing agents on crown retention. Crowns were fabricated for 50 molar teeth, and specimens were assigned to 5 groups based on treatment method: untreated control group (CON), laser group (LAS), sodium fluoride group (FLU), Oxagel oxalate group (OXA), and Gluma primer group (GLU). All crowns were luted with glass-ionomer cement. Tensile force was applied for crown dislodgement. Recorded forces and calculated retentive strengths were as follows: CON (261 N) > LAS (223 N) = FLU (208 N) > GLU (161 N) = OXA (147 N) (P < .05). The differences in force magnitudes between all groups were significant (P < .05), except for LAS versus FLU and GLU versus OXA. The retention decrease was 15% for LAS, 20% for FLU, 38% for GLU, and 44% for OXA. Laser treatment had a less negative effect on retention for crowns luted with glass-ionomer cement than the other treatment modalities, and it may be a more suitable desensitization method if crown retention can be moderately sacrificed.     

8DSS peptide induced effective dentinal tubule occlusion in vitro

Objective

Eight repetitive nucleotide sequences of aspartate–serine–serine (8DSS) derived from dentin phosphoprotein (DPP) has been proved to be a good remineralization agency. In this study, 8DSS peptide was employed to induce dentinal tubule occlusion.

Effect of dentinal tubule occlusion by dentifrice containing nano‐carbonate apatite

Summary This study evaluated the effects of the short‐term use of a dentifrice containing nano‐sized carbonate apatite (n‐CAP) on the occlusion of the dentinal tubules using a scanning electron microscope (SEM) and an image analyser in vitro. One hundred human dentine specimens were wet ground with a silicone carbide papers and etched with 6% citric acid for 1 min to allow complete opening of the dentinal tubule. Specimens showing complete opening tubules were used as the baseline. The specimens were divided randomly into five groups: G1: 0% n‐CAP, G2: 5% n‐CAP, G3: 10% n‐CAP, G4: 20% n‐CAP and G5: 10%strontium chloride (SrCl₂). Five specimens from each group were brushed by applying 50, 100, 250 and 500 strokes, respectively. All the specimens were evaluated by a SEM (×3000), and the degree of occlusion of the dentinal tubules was quantified using an image analyser. The results were analysed by one‐way anova and a Tukey’s test using the spss 12·0 statistical package program. The dentifrice containing 20% n‐CAP for 50 strokes, which indicated 2‐day use, showed the highest tubular occlusion than the other groups (P < 0·05). Moreover, this group showed 79·5% and 77·4% less open tubular area than the baseline and 0% n‐CAP group, respectively. The groups containing various concentrations of n‐CAP showed significant differences in the SrCl₂ group after tooth‐brushing for 500 strokes, which indicated 17‐day use. According to this examination of the short‐term use of desensitizing dentifrices in vitro, the dentifrice containing 20% n‐CAP was the most effective in occluding the dentinal tubules.     

Efficacy of desensitizing dentifrices to occlude dentinal tubules

Dentine hypersensitivity occurs when patent dentinal tubules are subjected to external stimuli, with pain being reduced by products that occlude tubules. This study compared the efficacy of a recently developed arginine-containing dentifrice, two established strontium-based products, and a fluoride control to occlude tubules when subjected to acid challenge. Dentine specimens with patent tubules were divided into four groups that were treated with a slurry consisting of one of the pastes mixed with stimulated human saliva. Treated specimens were further subdivided and soaked in 0.3% citric acid for 10 s, 30 s, 2 min, 5 min or 10 min. Tubule occlusion on representative scanning electron microscopy images was scored by blind review. All three desensitizing pastes offered good tubule occlusion, which was maintained to varying degrees following acidic challenge. After immersion in acid for 10 and 30 s, the strontium acetate- and arginine-containing pastes almost fully occluded tubules, but only the strontium acetate paste retained this level of occlusion after immersion in acid for 2 min, with strong statistical evidence that this paste occluded more tubules than the other pastes after immersion in acid for 2 or 5 min. This suggests that strontium acetate pastes may be the most effective at reducing dentine hypersensitivity.     

Root canal dentinal tubule disinfection

Dentinal tubules of the root canal walls of human teeth were infected in vitro with a known bacterial isolate. The roots were exposed to either calcium hydroxide or iodine potassium-iodide for various periods of time and the viability of microorganisms was determined by incubation of entire root samples in a culture medium. The effects of the two agents on microbial viability were evaluated and compared. Iodine potassium-iodide disinfected dentin effectively. In contrast, bacteria remained viable in the dentin after relatively extended periods of calcium hydroxide treatment.     

2种方法使用生物活性玻璃脱敏剂对牙本质小管封闭作用的场发射扫描电镜观察

目的使用场发射扫描电镜观察涂抹法和透明压膜托盘法使用生物活性玻璃脱敏剂在短时间内对牙本质小管的封闭效果,为增强生物活性玻璃的脱敏疗效提供新思路。方法制取56颗离体牙的牙本质片,6%柠檬酸脱矿后按处理方法和处理时间不同随机分为7组,涂抹法1 d组(A1组),涂抹法3 d组(A2组),涂抹法7 d组(A3组),压膜法1 d组(B1组),压膜法3 d组(B2组),压膜法7 d组(B3组),空白对照组。通过FESEM观察比较各组牙本质小管封闭效果。结果涂抹法和透明压膜托盘法使用生物活性玻璃脱敏剂后均能很好的封闭牙本质小管,牙本质小管内均可见明显矿化物沉积,A1、A2、A3、B1、B2、B3组牙本质小管的暴露率分别为(6.29±1.18)%、(3.40±0.84)%、(1.23±0.43)%、(5.31±0.97)%、(1.40±0.30)%、(0.36±0.15)%,A2组>B2组,A3组>B3组,差异有统计学意义;空白对照组牙本质小管口开放,周界清晰。结论透明压膜托盘法在短时间内可以增强生物活性玻璃对敏感牙本质小管的封闭效果,与涂抹法相比,封闭效果有提高,差异有统计学意义。     

In vitro study of dentinal tubule occlusion with sol-gel DP-bioglass for treatment of dentin hypersensitivity

DP-bioglass paste has been demonstrated to produce 60 microm of sealing depth on exposed dentinal tubules. However, the occlusive effect depended on a continuous placement of DP-bioglass paste on dentinal surface for three days. In a bid to fabricate highly reactive DP-bioglass particles, a sol-gel method was used together with HNO3, NaOH, and H3PO4 as catalysts. As a result, the application time of DP-bioglass paste was significantly reduced to 10 minutes. Percentage of tubular occlusion with DP-bioglass was 53.2-65.4%, while One Coat Bond and Seal & Protect yielded 51.3% and 41.2% respectively. Further, the average depth of tubular occlusion with DP-bioglass was 55.8-62.7 microm, while One Coat Bond and Seal & Protect produced 40.8 microm and 32.5 microm respectively. In conclusion, the best sealing performance of tubular occlusion was rendered by DP-bioglass catalyzed with HNO3. Its performance was significantly better than Seal & Protect, and was considered to exhibit the greatest potential in treating dentin hypersensitivity.     

Effectiveness of desensitizing agents.

This study was conducted to evaluate the efficacy of desensitizing agents for the treatment of dentin hypersensitivity. Seventy-five hypersensitive teeth in 10 patients were studied. These were divided into five groups of 15 hypersensitive teeth: group I, control (triple distilled water); group II, 10% strontium chloride; group III, 5% potassium nitrate; group IV, 2% sodium fluoride; and group V, 40% formalin. The stimulus used to test thermal sensitivity was cold water at 15 degrees C, 10 degrees C, 5 degrees C, and 0 degrees C applied on every alternate day for 10 days. Results showed that 10% strontium chloride solution, 2% sodium fluoride solution, and 40% formalin solution significantly reduced dentin hypersensitivity, whereas a 5% solution of potassium nitrate did not.     

Tubular occlusion of simulated hypersensitive dentin by the combined use of ozone and desensitizing agents

Abstract

Objective. Ozone was suggested for treatment of hypersensitive dentin. The purpose of this study was to investigate the effect of ozone, with or without the use of desensitizing agents, on patency and occlusion of simulated hypersensitive dentin. Materials and methods. Sixty standardized dentin slabs were randomly divided into six groups: distilled water (Control), ozone treatment, fluoride desensitizer (ALLSolutions, Dentsply), oxalate desensitizer (D/Sense Crystal, Centrix), combined use of ozone/fluoride and combined use of ozone/oxalate. Ozone gas was delivered from OzonyTronX (Mymed). Specimens were evaluated using a scanning electron microscope and digital image analysis before and after treatment. Results. Statistical analysis using ANOVA and Mann-Whitney U-tests revealed significantly lower percentage of tubular occlusion with ozone treatment than distilled water at p ≤ 0.05. Scanning electron microscope photomicrographs of oxalate desensitizer specimens revealed a thick homogenous precipitate with significantly higher percentage of tubular occlusion than fluoride desensitizer and distilled water. Combined use of ozone/fluoride resulted in a significantly higher percentage of tubular occlusion than fluoride desensitizer alone. However, no significant difference was found between oxalate desensitizer and combined use of ozone/oxalate. Conclusion s . The use of ozone gas is a viable adjunct to fluoride-containing desensitizers in enhancing tubular occlusion, but is not effective with oxalate desensitizers.