人深层牙本质粘结时牙髓反应的短期评价

目的 :评价两种不同体系的牙本质粘结系统直接用在人深层牙本质上时牙髓 -牙本质复合体在短期内的反应。方法 :局麻下在 2 4颗因正畸治疗需要而计划拔除的前磨牙的颊面颈部预备深Ⅴ类洞 ,随机分为两组 ,一组牙齿的窝洞各壁直接应用全酸蚀牙本质粘结系统Prime&BondNT ,光固化复合树脂充填 (PB组 ) ;另一组的窝洞内则直接使用自酸蚀牙本质粘结系统XenoⅢ (Xeno组 )。以上所有的牙齿在术后 7～ 2 0d之间拔除 ,常规组织病理切片预备 ,HE、Masson’strichrome、BrownandBrenn染色 ,显微镜下盲法评价其牙髓 -牙本质复合体的反应。结果 :PB组中有大量粘结树脂成分沿着牙本质小管扩散 ,同时牙髓出现较为明显的炎症反应和组织结构紊乱。相比之下 ,Xeno组牙髓的不良反应较小。结论 :在深窝洞中直接使用全酸蚀牙本质粘结系统Prime&BondNT是不恰当的 ,此时使用自酸蚀牙本质粘结系统XenoⅢ较为安全。     

三氧化矿物凝聚体治疗髓室底穿孔临床观察

〔摘 要〕 目的：分析三氧化矿物凝聚体（MTA）治疗髓室底穿孔的可行性及有效性。方法：选取江门市口腔医院及江 门市五邑中医院 2019 年 6 月至 2020 年 6 月期间收治的 100 例髓室底穿孔患者,以随机单盲法分为对照组与观察组,各 50 例。 对照组以常规材料修复髓室底,观察组以 MTA 修复。比较分析 MTA 治疗髓室底穿孔的可行性及有效性。结果：观察组患 者治疗有效率为 96.0 %,高于对照组的 84.0 %,差异具有统计学意义（P ＜ 0.05）;观察组患者不良反应发生率为 2.0 %, 低于对照组的 14.0 %,差异具有统计学意义（P ＜ 0.05）;观察组患者的牙齿美观度总满意率为 96.0 %,高于对照组的 80.0 %, 差异具有统计学意义（P ＜ 0.05）。结论：采用 MTA 作为髓室底穿孔的修复材料,可有效修复受损牙体,引发的不良反应少, 牙齿美观度高。     

基于CBCT对汉族人下颌第一恒磨牙髓室高度及牙本质厚度与年龄关系的研究

目的:应用CBCT研究汉族人下颌第一恒磨牙髓室高度和牙本质厚度与年龄的关系.方法:收集汉族受试者420 例(男、女各210 例)下颌第一磨牙CBCT影像资料,分6 组(15~24 岁、25~34 岁、35~44 岁、45~54 岁、55~64 岁、65~74岁).运用CBCT自带软件测量牙齿中轴线上髓室的高度和牙本质厚度,进行统计学分析.结果:髓室高度:男性(0.85±0.54) mm、女性(0.79±0.51) mm;髓室顶牙本质厚度:男性(3.60±0.49) mm,女性(3.50±0.49) mm;髓室底牙本质厚度:男性(2.57±0.52) mm,女性(2.49±0.51) mm,随年龄增长髓室高度减小,牙本质厚度增加,与年龄有相关关系(P<0.05),髓室底牙本质厚度增大速率明显高于髓室顶(P<0.05),性别间均无统计学差异(P>0.05).结论:随年龄增长汉族人下颌第一磨牙髓室高度减小,牙本质厚度增大,髓室底牙本质厚度增加较髓室顶更明显.     

Tricalcium Silicate Capping Materials Modulate Pulp Healing and Inflammatory Activity In Vitro

Introduction

On stimulation by lipoteichoic acid or by a physical injury, fibroblasts have been shown to play a major role in the initiation of the pulp inflammatory reaction and healing through secretion of complement proteins and growth factors. The application of direct pulp-capping materials on these cells may interfere with the inflammatory and the healing processes within the pulp's inextensible environment. This work was designed to study in vitro the effects of silicate-based materials on pulp fibroblast modulation of the initial steps of pulp inflammation and healing.

Histologic characterization of regenerated tissues after pulp revascularization of immature dog teeth with apical periodontitis using tri-antibiotic paste and platelet-rich plasma

IntroductionThis study evaluates histologically the efficacy of 4 revascularization protocols in necrotic-infected immature dog teeth with apical periodontitis (AP).MethodsForty double-rooted immature premolar teeth from 4 female Beagle dogs aged 5 months were used. Four teeth were left untouched as negative controls; the other 36 teeth were infected to develop pulp necrosis and AP. Four teeth were left untreated and assigned to the positive control group. The last 28 teeth were randomly assigned into four experimental groups of 8 teeth, each one treated with a different treatment protocol: A1, sodium hypochlorite (SH) + blood clot (BC); A2, SH + platelet-rich plasma (PRP); B1, SH + modified tri-antibiotic paste (mTAP) + BC; B2, SH + mTAP + PRP. The animals were sacrificed, histologic sections were prepared and three parameters were assessed: (1) presence or absence of new hard tissue on the internal root dentinal walls, (2) presence or absence of continued apical closure, and (3) presence or absence of vital tissue within the canal space.ResultsSignificant differences (p < 0.05) between the four experimental groups were evident in the percentage of teeth showing histological apical closure (34.5%) and vital tissue within the canal space (68.8%). Group B2 showed the maximal improvement in the three variables assessed (p < 0.05). Group A1 showed the minimum percentages in the three parameters assessed (p < 0.05).ConclusionsThese results suggest that an intracanal dressing of mTAP, and the use of PRP as scaffold, improves the success rate of the revascularization procedure.     

Sonic Hedgehog信号通路在大鼠牙髓炎中的作用

目的:观察Sonic Hedgehog(Shh)信号分子在大鼠牙髓炎中的免疫定位,探讨Shh信号通路在牙髓防御和修复中所起的作用。方法:将15只SD大鼠随机分成1d、3d和7d组,每组5只,用穿髓开放法建立大鼠牙髓炎模型,3组大鼠分别于术后1,3,7d处死,取出下颌磨牙,常规组织学处理,免疫组化方法检测Shh,Smo,Ptc,Gli1的表达,并对Shh信号通路在大鼠牙髓炎中的表达进行半定量分析,对照组为大鼠正常牙髓。结果:大鼠牙髓炎模型1,3,7dShh广泛表达于穿髓孔下方牙髓间充质细胞及远离穿髓孔的根髓细胞中,表达量随炎症的进展无显著性提高(P>0.05)。Ptc、Smo、Gli1在大鼠牙髓损伤后1d未见阳性表达,3d和7d均表达于穿髓孔下方牙髓间充质细胞中,且表达量均有显著性提高(P<0.05)。空白对照组中Shh信号通路阴性表达。结论:Shh信号通路在牙髓炎过程中表达,提示其可能被激活,参与牙髓炎症反应。     

吻合血管的掌短肌皮瓣修复拇指指腹缺损

对掌短肌皮瓣的应用解剖进行了复习和研究后，在临床上对２例拇指指腹缺损的患者，采用吻合血管的掌短肌皮瓣进行修复。术后拇指指腹缺损完全修复愈合，指腹有感觉，供手区无疼痛及感觉障碍，运动正常。掌短肌皮瓣质地与拇指指腹相似，耐磨，切取的面积较大，可带感觉神经，是修复拇指较大面积缺损的较好供区之一。     

A comparison of Ca2+-, Mg2+-ATPase and alkaline phosphatase activities of rat incisor pulp

Summary A plasma membrane preparation derived from incisor pulps of 250-g rats was used as the source of alkaline phosphatase and an ATPase activated by either Ca²⁺ or Mg²⁺. Properties of the two enzymes were then compared under a variety of experimental conditions to determine if ATPase activity is clearly distinct from alkaline phosphatase activity. (a) The optimum pH for ATP hydrolysis was 8.0, compared with 10.2 forp-nitrophenylphosphate. (b) At the optimum pH, ATP hydrolysis required either Ca²⁺ or Mg²⁺ for activation, whereasp-nitrophenylphosphate hydrolysis did not require and was little influenced by the presence of divalent cations. (c) Alkaline phosphatase showed maximal activity at 40°C and ATPase at 50°C, with complete inactivation at 60°C and 70°C, respectively. (d) When the plasma membrane preparation was preincubated in the absence of substrate at varying temperatures of pH, alkaline phosphatase was less stable than ATPase at extreme pH and high temperatures. (e) Alkaline phosphatase activity was lost more rapidly than ATPase activity during storage at 4°C for up to 10 days. (f) Butanol extraction of the plasma membrane preparation to remove phospholipid destroyed ATPase activity and enhanced alkaline phosphatase activity approximately fivefold. On the basis of these comparisons it is concluded that ATP hydrolysis andp-nitrophenyl-phosphate hydrolysis are the result of separate enzyme activities.     

Automatic stimulus breaker for electric dental pulp tester using pain response

The pulp test provides a means of examining the vitality of dental pulp using physical or chemical stimulation. During electrical pulp testing, an electrical current stimulates the intradental nerve, which may be painful and stressful to patients. The study involved measurement of the electromyogram (EMG) from the anterior belly of the digastric muscle, finger movement and voice response during electrical pulp testing. The excessive stimulus time from the onset time of response (EMG, voice and finger movement) to the end of the stimulation was obtained. The results indicated that the responses occurred in the order: EMG, finger and voice. Based on these results, an automatic stimulus shut-off circuit was developed using the above-mentioned responses to stimulus during electric pulp testing. Excessive stimulus time was reduced by prompt switching-off of the pulp tester output, 64 ms on average after the first detected response (EMG). Consequently, excessive stimulus times were reduced by 284 and 152 ms on average for the subject and examiner disconnection, respectively, using the developed automatic shut-off circuit. Therefore it was possible to minimise pain and stress by reducing excessive pulp stimulation.     

Influence of heat from light curing units and dental composite polymerization on cells in vitro

OBJECTIVES: The aim of the present study was to test the hypothesis that the use of a light curing unit (LCU) with high light power would result in a higher temperature and therefore a statistically significant lower number of living human gingiva fibroblasts within a pulp chamber model than the use of a light emitting diode (LED) LCU. MATERIALS AND METHODS: The composites Admira, Grandio, Filtek Supreme and Filtek Z250 were polymerized with the LCUs Swiss Master Light, Optilux 501 and an LED LCU prototype in a mould on top of a pulp chamber model. The temperature was recorded within the pulp chamber with a thermocouple. The cytotoxicity of the polymerized samples was tested by using the MTT test. RESULTS: In general there was no considerable difference in the temperature increase within the pulp chamber model for the different LCUs and composites. There was no statistically significant difference in the cell number (p=0.3767) when the different LCUs were used. CONCLUSIONS: Using a high power halogen LCU for a short time or a standard halogen or LED LCU for a longer time did not result in a considerable difference in the temperature increase or the number of living cells within a pulp chamber model. This study indicates not only that the temperature may have an effect on the living cells, but also that cells may be negatively affected by the unpolymerized composite or light of the LCUs.