Periodontal conditions among the middle-aged and the elderly in Hong Kong

Abstract The aim of this study was to describe the periodontal conditions in 372 35–44-yr-old and 537 noninstitutionalized 65–74-yr-old Hong Kong Chinese who were examined clinically for loss of attachment, recession, probing depth, calculus, and bleeding after probing. Community Periodontal Index (CPI) data and treatment need indications were compiled from index teeth or their substitutes. The prevalence of loss of attachment varied considerably in both cohorts according to the definition of the threshold (≥6, ≥9, and ≥12 mm, respectively). The mean numbers of teeth with loss of attachment at the ≥6-mm threshold and at higher thresholds were small. In both age cohorts, about one-fifth of subjects had probing depths ≥6-mm, while al the ≥9-mm threshold only 2–3% were so affected. Although recession was an important component of loss of attachment in the younger cohort, in the older cohort the prevalence and extent of recession were greater than for probing depths at thresholds ≥4 mm. All subjects had one or more teeth with calculus, bleeding, or both, most teeth being so affected. Eighty-four of the 537 65–74-yr-old subjects were excluded either because of edentulousness or because extractions indicated for the remaining teeth would have rendered the subjects edentulous. The distribution of subjects according to their highest CPI score was remarkably similar for the two cohorts. No subjects in either age group were assessed as “healthy” (CPI code 0) or had “bleeding only” (code 1) as their highest score. While most subjects scored CPI code 2 or 3 us their highest score, only 17% of the younger and 15% of the older cohort scored Community Periodontal Index of Treatment Needs (CPITN) code 4. Differences in the mean number of sextants affected by CPI codes between the two cohorts were mainly due to a greater number of excluded sextants in the older cohort. CPI findings for 35–44-yr-olds differed little from those reported in 1984.     

Study of nerve regeneration in centrocentral anastomosis

Summary Nerve regeneration was studied in a model of centrocentral anastomosis (CCA) performed on the sciatic nerve of the rat. Experimental CCA was made by suturing the proximal end of the peroneal branch on the proximal end of the sural branch, placing between them a peroneal nerve graft (Group I, 20 rats) or a silicone chamber (Group II, 12 rats). Nerve grafts had a length of 5mm and silicone chambers 7 mm. In six silicone chambers an 1 mm nerve graft was placed in the centre of the tube. In group I animals anterograde degeneration was studied by cutting the graft 60 days after surgery. In group II, nerve regeneration was studied 2, 4 and 8 weeks after surgery. Results indicate that in CCA: 1) regenerated axons coming from one nerve end grow into the graft but do not cross the contralateral suture line; 2) regeneration is poorer in silicone chambers than in nerve grafts; and, 3) in silicone chambers regeneration is related to time. The reduction in the regenerative capability in CCA seems to be related to the alteration of nerve sprouts aiming for the peripheral targets.     

Comparative effects of plateletderived growth factor-BB and insulin-like growth factor-I, individually and in combination, on periodontal regeneration in Macaca fascicularis

Platelet-derived growth factor (PDGF) and insulin-like growth factor I (IGF-I) in combination have previously been shown to enhance periodontal regeneration. The objective of this study was to further characterize the biological effects of this combination of growth factors in non-human primates and compare the effects to those of each growth factor individually. Ligature-induced periodontitis was initiated in 10 cynomolgus monkeys. After periodontal lesions were established, surgery was performed, and either a methylcellulose gel vehicle or vehicle containing 10 μg each of either PDGF-BB, IGF-I or both PDGF-BB and IGF-I was applied to exposed root surfaces. Biopsies were taken 4 and 12 wk after treatment and the extent of periodontal regeneration was assessed by histomorphometry. At both 4 and 12 wk vehicle-treated lesions generally revealed minimal osseous defect fill (ODF) (8.5±2.1% and 14.5±5.7%, respectively) and new attachment (NA) (34.1±5.2% and 26.6±10.5%, respectively). IGF-I treatment did not significantly alter healing compared to vehicle in any parameter at both 4 and 12 wk. PDGFBB-treated sites exhibited significant (p<0.05) regeneration of NA (69.6±12.0%) at 12 wk; trends for PDGF-BB treatment effect were also observed in other parameters at 4 and 12 wk. although these increases were not statistically significant. Treatment with PDGF-BB/IGF-I resulted in 21.6±5.1 % and 42.5±8.3% ODF at 4 and 12 wk, respectively, and 64.1±7.7% and 74.6±7.4% NA at 4 and 12 wk, respectively (all significantly greater than vehicle, p<0.05). The results from this study demonstrated that: 1) IGF-1 alone at the dose tested did not significantly alter periodontal wound healing; 2) PDGF-BB alone significantly stimulated NA, with trends of effect on other parameters; and 3) the PDGF-BB/IGF-I combination resulted in significant increases in NA and ODF above vehicle at both 4 and 12 wk.     

90例慢性牙周炎临床分析

目的评价不同治疗方法对慢性牙周炎的临床效果。方法对90例慢性牙周炎患者,随机分成三组:龈上洁治术 抗生素组(A组),单纯龈上洁治术组(B组)和单纯抗生素组(C组)。分别给予不同的治疗,在治疗后1周、2周和4周记录牙周袋探诊深度(PPD)、探诊附着水平(PAL)、菌斑指数(PLI)、龈沟出血指数(SBI)。结果治疗1周和2周后各指标显著减轻(P<0.05),2周比1周减轻更明显(P<0.05),4周与2周比较无明显差异(P>0.05),A组各指标减轻比B组显著(P<0.05);B组比C组疗效显著(P<0.05)。结论A组作用优于B组(P<0.05),B组优于C组(P<0.05)。     

体外培养诱导外周血淋巴细胞促进大鼠面神经再生的实验研究

目的:通过在神经缺损处局部回输体外分离培养纯化的淋巴细胞,了解此种方法促进面神经损伤修复的效果。方法:将20只Wistar大鼠的面神经颊支剪断并立即缝合(其余3支反折缝合)制成面神经损伤模型大鼠,将其分成淋巴细胞组和对照组,每组10只,每组再分成2周组和8周组。淋巴细胞组局部回输体外分离培养的外周血淋巴细胞,对照组作对照。于2周和8周测定面神经颊支-触须肌复合动作电位传导速度,辣根过氧化物酶(HRP)神经逆行示踪测定面神经核团的神经元阳性数目。结果:淋巴细胞组面神经颊支-触须肌复合动作电位传导速度8周时为0.64±0.07,与对照组(0.56±0.07)相比,差异有统计学意义(P<0.05)。HRP神经逆行示踪测定面神经核团神经元阳性数目,淋巴细胞组2周及8周与对照组同时间段相比差异均无统计学意义(均P>0.05)。结论:体外分离培养纯化的淋巴细胞在局部应用于神经损伤处对面神经再生修复可起一定的促进作用。     

重视神经、内分泌与免疫机制在皮肤修复与再生中作用的研究

目的概述神经、内分泌与免疫学机制的变化对皮肤修复的影响,以及近年来的研究进展,为深入开展这一领域的研究和临床治疗提供依据.方法广泛阅读国内外相关文献,并进行分析、综合,确定神经、内分泌与免疫机制在皮肤修复中的作用.结果皮肤作为神经依赖性器官、内分泌器官及免疫器官,在皮肤损伤修复与再生中发挥重要作用.结论目前对这一领域研究较少,应加强相关基础研究.     

大网膜包裹人工神经移植体再血管化及神经再生的研究

目的 探讨大网膜包裹人工神经移植体的早期再血管化，以及增强移植体血供对神经再生的影响。方法 75只大耳白兔制作成左前肢正中神经2．0cm缺损，随机分成3组：A组，带蒂大网膜包裹人工神经移植体移植；B组，人工神经移植体桥接神经缺损；C组，自体神经桥接神经缺损，作为对照组。术后3、7和14d应用伊凡思蓝（evans blue bound to albumin，EBA）毛细血管造影，检测各组移植体的再血管化；术后12周通过电生理、光镜、透射电镜等检测评估神经再生的效果。结果 A、C组术后3d移植神经出现再血管化，7d和14d再血管化程度逐渐增强；B组7d出现再血管化，与A、C组比较，再血管化延迟。术后12周，A组和C组运动神经传导速度、有髓神经纤维密度、神经内纤维组织面积及面积比、髓鞘厚度、髓鞘直径等差异无统计学意义（P〉0．05），但均优于B组，差异有统计学意义（P〈0．05）。结论 大网膜包裹人工神经移植体可促进移植体早期再血管化，增强移植体血供，促进神经再生。     

复合神经营养因子的神经导管研究进展

目前周围神经的组织工程研究热点之一就是研制具有生物活性的神经导管,主要方法是神经导管与雪旺细胞或者神经营养因子相结合来促进周围神经的再生。就复合神经营养因子的神经导管的相关研究进展作一综述。     

自体移植脾组织VEGF、KDR表达与血管再生的实验研究

目的 研究自体移植脾组织血管再生及VEGF、KDR表达规律，阐明VEGF、KDR对移植脾组织血管再生的调控作用，为脾脏外科临床及实验研究提供理论依据。方法 健康Wistar大鼠70只，体重100—120g，随机分为7组，每组10只中又设脾切除自体脾移植组5只，假手术组5只，分别于术后7，14，30，60，90，120，180d进行：(1)自体移植脾组织病理学检测；(2)大鼠行主动脉插管灌注墨汁，光镜观测再生血管并采用图像分析测定其密度；(3)免疫组化抗VEGF、KDR抗体染色，图像分析定量，阐明其表达规律及与血管再生的关系。结果 (1)自体脾组织移植术后7d即有血管从大网膜向脾组织内伸展，移植脾组织内血管密度逐渐增大，至术后180d血管再生接近正常；(2)自体脾组织移植术后7d、14d，VEGF、KDR阳性染色细胞密度迅速升高，术后60d达高峰，以后逐渐降低，至术后180d VEGF、KDR阳性染色细胞密度趋向正常。结论 自体脾组织大网膜内移植术是简便有效的脾移植方法；移植脾组织新生血管由大网膜再生而来；术后移植脾组织内VEGF、KDR表达量升高，促进血管形成，血管再生完成后恢复正常水平。     

应用和推广烧伤皮肤再生医疗技术的体会(二)

目的：通过临床实践总结、分析、认识干细胞与再生医学理论在烧伤创疡中的作用与效果；方法：应用MEBT／MEBO观察烧伤创疡创面的再生修复变化。结果：MEBT／MEBO治疗77种创疡疾病冶愈率达92％以上，有效率达100％。结论：MEBT／MEN)治疗慢性体表性溃疡及皮肤病性皮肤损伤、感染性溃疡效果满意。