臭氧对口腔科诊室空气消毒效果的研究

目的 观察臭氧对口腔科诊室空气常见致病菌的杀菌效果。方法 用碘滴定法测定打开臭氧发生器不同机组及不同时间时的臭氧浓度,按平板自然沉降法采集细菌,根据细菌集落数,计算出空气中的细菌数量,并计算杀菌率,确定细菌的种类。所得数据采用SAS6.12软件包进行卡方检验。结果 ①随着打开臭氧发生器组数的增加和时间的延长,诊室内臭氧浓度逐步升高,最低为240mg/m3,最高可达2736mg/m3;②臭氧的灭菌率普遍高于紫外线;③浓度为2736mg/m3的臭氧作用45min对变链菌的杀菌率最高为100%。结论 臭氧灭菌效果高于紫外线,可作为口腔科诊室的常规消毒方法。     

常用根管冲洗液与臭氧液杀菌效果的实验研究

目的：比较常用根管冲洗消毒液与HYCY40009型臭氧仪产生的不同浓度臭氧液的杀菌效果。方法：采用细菌悬液定量实验法测定5组消毒液对3株兼性厌氧菌和2株专性厌氧菌的杀菌效果。结果：杀菌率随着臭氧液浓度的增加而提高,臭氧液对微生物的杀灭率随着时间延长而增高。当增加臭氧液浓度（1．339mg／L）和作用时间（5min）时,其杀菌效率与常用的根管冲洗液3％双氧水、0．25％次氯酸钠液的杀菌效果一致。结论：HY-CY40009型臭氧发生仪在通电40min内可以产生具有理想消毒杀菌作用的臭氧液。对于感染根管的冲洗消毒应用具有较好前景。     

臭氧对4种细菌的灭活作用

目的:观察不同浓度臭氧在不同作用时间下对金黄色葡萄球菌、变形链球菌、表皮葡萄球菌和肺炎链球菌的灭活作用.方法:用碘滴定法测定打开臭氧发生器不同机组及不同时间时的臭氧浓度,按载体定量杀菌试验,将经臭氧作用的载体与相同环境下未经臭氧作用的载体上的细菌洗下,各取洗脱液50μl,接种于TSA平板并置厌氧箱(90%N2,10%CO2,37°C)培养24～48h后,进行活菌菌落计数.所得数据采用SAS 6.12软件包进行X.检验.结果:臭氧浓度越高、作用时间越长.杀菌效果越好.臭氧浓度2.73mg/L、作用45min时,对4种细菌的杀灭率达100%.结论:臭氧对4种细菌有良好的灭活作用,且杀菌效果有随臭氧浓度增加而增强的趋势.     

几种根管冲洗液对L929细胞毒性的实验研究

目的:采用MTT法比较臭氧水溶液与临床常用根管冲洗液对L929细胞的细胞毒性。方法:应用碘量法测定一种臭氧发生器产生臭氧水溶液的最高浓度。体外培养L929细胞,分别以2.15mg/L臭氧水溶液(实验测得最高浓度臭氧水溶液)、3%过氧化氢液、1%次氯酸钠和17%EDTA液作用于细胞6h、12h和24h,生理盐水作为空白对照组,采用MTT法检测不同时间不同组细胞增殖度,测定各组细胞活性。结果:试验用臭氧发生器所产生最高浓度臭氧水溶液浓度约2.15mg/L;MTT实验结果显示,2.15mg/L臭氧水溶液对L929细胞无明显细胞毒性,与阴性对照生理盐水组相比不具有统计学差异。而3%过氧化氢、1%次氯酸钠和17%EDTA液均具有显著的细胞毒性,且随时间延长表现出更强的细胞毒性。细胞毒性按1%次氯酸钠、3%过氧化氢、17%EDTA顺序递减。结论:2.15mg/L臭氧水溶液具有优良的生物相容性,细胞毒性显著低于临床常用的其他根管冲洗剂。     

慢性牙周炎患者牙周袋内臭氧油存留时间及有效浓度研究

目的 研究慢性牙周炎患者牙周袋内臭氧油有效浓度及存留时间。方法 选取2017年1月至2018年1月廊坊市人民医院口腔科就诊的慢性牙周炎患者200例,将其随机分为A组（84例）与B组（116例）,疗效考察指标为：菌斑指数（PLI）、牙龈指数（GI）、探诊深度（PD）、探诊出血（BOP）和附着丧失指标（AL）;将A组患者随机分为6组,每组14例患者,设对照组、臭氧浓度10 g/L、40 g/L、60 g/L、80 g/L、110 g/L进行单因素试验,对臭氧油浓度与治疗效果进行对比研究;将B组患者随机分为6组,设定臭氧油存留时间30 s、10 min、20 min、30 min、40 min及60 min进行单因素试验,对臭氧油存留时间与治疗效果进行对比研究。结果 与治疗前相比,A组患者通过不同浓度的臭氧油治疗后,各组AL、PD、PLI、GI、BOP指标均显著降低（P<0.05）,且当臭氧油浓度大于60 g/L时,治疗后的PLI、GI、AL均显著低于对照组（P<0.05）;与治疗前相比,B组患者治疗过程中保持臭氧浓度为60 g/L,且在牙周袋内存留时间大于等于30 min时,AL、PD、PLI均显著降低（P<0.05）。结论 慢性牙周炎患者牙周袋内臭氧油有效浓度及存留时间对于患者的病情改善具有重要的意义,值得临床重点关注。     

臭氧水溶液对牙本质微硬度影响的实验研究

目的:评价臭氧水溶液对根管内壁牙本质微硬度的影响。方法:选取40颗因正畸拔牙的离体前磨牙随机分为5组,A组:2.15 mg/L臭氧水溶液组;B组:1%次氯酸钠组;C组:3%过氧化氢组;D组:15%EDTA组;E组:蒸馏水组(阴性对照组)。将牙冠于牙颈部截断后将牙冠沿牙体长轴纵向劈开暴露牙本质,以5组不同根管冲洗液分别处理5 min、15 min后用微硬度测试仪测定牙本质的微硬度。结果:1%次氯酸钠,3%过氧化氢,15%EDTA均降低了牙本质的微硬度,尤以15%EDTA为甚,而2.15 mg/L臭氧水溶液对牙本质微硬度无明显影响。结论:2.15 mg/L臭氧水溶液作为根管冲洗液对牙本质微硬度没有影响。     

臭氧水对伴放线放线杆菌的灭活效果观察

目的探讨臭氧水对牙周可疑致病菌伴放线放线杆菌（Aa）的灭活效果。方法采用悬液定量杀菌方法和和化学方法在实验室进行观察。用4、8、15mg／L的臭氧水分别对悬液中A。作用1、2、3min。结果当臭氧水浓度为4mg／L对悬液中An没有杀灭作用。当臭氧水浓度为8mg儿时,对悬液中An作用1min,杀灭率为57％,当浓度上升至15mg／L时,对悬液中Aa作用1min．杀灭率上升至98％．而延长杀菌时间至3min．杀菌率维持在97％～99％。结论在25℃的室温条件下．臭氧水浓度达到15mg／L．臭氧水温控制在15℃～18℃时对悬液中Aa有快速、有效的杀灭作用。     

臭氧水溶液对牙周可疑致病菌作用的研究

目的：评价臭氧水溶液对常见牙周可疑致病菌的杀菌效果。方法：采用细菌悬液定量实验法,测定不同浓度的臭氧水溶液对牙龈卟啉单胞菌（P．g）ATCC33277、伴放线菌嗜血菌（H．a）ATCC29522、具核梭杆菌（F．n）ATCC10957和牙龈卟啉单胞菌临床分离株作用30、60、90、120 s 的杀菌率,阳性对照组采用不同浓度的过氧化氢溶液,阴性对照组采用蒸馏水。实验样本在厌氧培养72 h 后进行菌落计数并计算杀菌率。结果：臭氧水溶液对几种牙周可疑致病菌均有杀灭效果,且杀菌率随浓度的增加而提高（P ＜0．01）。对 P．g 标准株和临床分离株的杀菌率差异无统计学意义（P ＞0．05）。线性回归分析臭氧水溶液对3种细菌杀灭作用的浓度影响因素β值均大于0．95,时间影响因素β值均小于0．11。结论：臭氧水溶液对牙龈卟啉单胞菌、伴放线菌嗜血菌和具核梭杆菌具有浓度依赖性杀灭效果。     

臭氧水溶液去除根管内玷污层的扫描电镜观察

目的：观察臭氧水溶液对根管内玷污层的去除效果。方法：40颗离体单根牙随机分为5组,应用逐步后退法进行根管预备。A组：2.15 mg/L臭氧水溶液组;B组：3%过氧化氢加生理水组;C组：2.15 mg/L臭氧水溶液加1%次氯酸钠组;D组：17%EDTA加5.25%次氯酸钠组（阳性对照组）;E组：三蒸水组（阴性对照组）。根管预备过程中使用各冲洗液冲洗根管,然后将牙体沿牙体长轴纵向劈开,并应用扫描电镜对根管中1/3进行观察,结果进行统计学分析并摄片。结果：17%EDTA加5.25%次氯酸钠组去除玷污层效果最好,但有牙本质小管口增宽和管间牙本质过度脱矿现象。2.15 mg/L臭氧水溶液组对根管玷污层有一定去除作用,而2.15 mg/L臭氧水溶液加1%次氯酸钠组对玷污层的去除能力优于单纯臭氧水溶液组。3%过氧化氢液加生理盐水组和三蒸水组对玷污层能力很小,但双氧水组稍好于三蒸水组。结论：2.15 mg/L臭氧水溶液具有去除根管玷污层的潜力,将该浓度臭氧水溶液和次氯酸钠联合使用对根管玷污层有一定去除作用,且对牙本质无腐蚀作用。     

臭氧老化对SY-1硅橡胶色彩稳定性的影响

目的 :了解臭氧老化对内着色SY 1硅橡胶色彩稳定性的影响 ,以便为选用适宜的硅橡胶着色颜料提供理论依据。方法 :SY 1硅橡胶按所加色料不同分为 4组 (对照组、水粉颜料土黄色、油画颜料土黄色、无机盐类颜料中铬黄 ) ,按国家标准对其进行臭氧老化并测定老化前后L 、a 、b 值 ,据此计算△E值。结果 :经臭氧老化 72h ,对照组△E为 0 .5 5± 0 .11;水粉土黄组△E为 3 .5 5± 0 .0 9;油画土黄组△E为 1.40± 0 .11;中铬黄组△E为 1.5 7± 0 .0 7。结论 :SY 1硅橡胶在臭氧老化条件下 ,油画类颜料与无机盐类颜料色彩稳定性优于水粉颜料。     

An in vitro evaluation of the ability of ozone to kill a strain of Enterococcus faecalis

AIM: To evaluate the potential of ozone as an antibacterial agent using Enterococcus faecalis as the test species. METHODOLOGY: Ozone was produced by a custom-made bench top generator and its solubility in water determined by ultraviolet (258 nm) spectrophotometric analysis of solutions through which ozone was sparged for various time-periods. The antibacterial efficacy of ozone was tested against both broth and biofilm cultures. Ozone was sparged for 30, 60, 120 and 240 s, through overnight broth cultures of a strain of E. faecalis (E78.2) and compared with those that were centrifuged, washed and resuspended in water. Enterococcus faecalis (E78.2) biofilms were grown on cellulose nitrate membrane filters for 48 h and suspended in water through which ozone gas was sparged with stirring for 60, 120 and 240 s in a standard fashion. In a separate test, biofilms were also exposed to gaseous ozone. Sodium hypochlorite (NaOCl) was used as a positive control. All experiments were repeated four times. RESULTS: There were significant (P < 0.05) reductions of bacteria in the unwashed (2 log(10) reductions) and washed (5 log(10) reductions) broth cultures following 240 s applications. Biofilms incubated for 240 s with ozonated water showed no significant reduction in cell viability attributable to ozone alone, whereas with NaOCl no viable cells were detected over the same time. Gaseous ozone applied for 300 s had no effect on these biofilms. CONCLUSIONS: Ozone had an antibacterial effect on planktonic E. faecalis cells and those suspended in fluid, but little effect when embedded in biofilms. Its antibacterial efficacy was not comparable with that of NaOCl under the test conditions used.     

Effect of ozone on oral cells compared with established antimicrobials

Ozone has been proposed as an alternative antiseptic agent in dentistry based on reports of its antimicrobial effects in both gaseous and aqueous forms. This study investigated whether gaseous ozone (4 x 10(6) microg m(-3)) and aqueous ozone (1.25-20 microg ml(-1)) exert any cytotoxic effects on human oral epithelial (BHY) cells and gingival fibroblast (HGF-1) cells compared with established antiseptics [chlorhexidine digluconate (CHX) 2%, 0.2%; sodium hypochlorite (NaOCl) 5.25%, 2.25%; hydrogen peroxide (H(2)O(2)) 3%], over a time of 1 min, and compared with the antibiotic, metronidazole, over 24 h. Cell counts, metabolic activity, Sp-1 binding, actin levels, and apoptosis were evaluated. Ozone gas was found to have toxic effects on both cell types. Essentially no cytotoxic signs were observed for aqueous ozone. CHX (2%, 0.2%) was highly toxic to BHY cells, and slightly (2%) and non-toxic (0.2%) to HGF-1 cells. NaOCl and H(2)O(2) resulted in markedly reduced cell viability (BHY, HGF-1), whereas metronidazole displayed mild toxicity only to BHY cells. Taken together, aqueous ozone revealed the highest level of biocompatibility of the tested antiseptics.     

Effectiveness of ozone against periodontal pathogenic microorganisms

Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.     

Effectiveness of ozone against endodontopathogenic microorganisms in a root canal biofilm model

Aim To assess the antimicrobial efficacy of aqueous (1.25–20 μg mL^?1) and gaseous ozone (1–53 g m^?3) as an alternative antiseptic against endodontic pathogens in suspension and a biofilm model. Methodology Enterococcus faecalis, Candida albicans, Peptostreptococcus micros and Pseudomonas aeruginosa were grown in planctonic culture or in mono‐species biofilms in root canals for 3 weeks. Cultures were exposed to ozone, sodium hypochlorite (NaOCl; 5.25%, 2.25%), chlorhexidine digluconate (CHX; 2%), hydrogen peroxide (H₂O₂; 3%) and phosphate buffered saline (control) for 1 min and the remaining colony forming units counted. Ozone gas was applied to the biofilms in two experimental settings, resembling canal areas either difficult (setting 1) or easy (setting 2) to reach. Time‐course experiments up to 10 min were included. To compare the tested samples, data were analysed by one‐way anova . Results Concentrations of gaseous ozone down to 1 g m^?3 almost and aqueous ozone down to 5 μg mL^?1 completely eliminated the suspended microorganisms as did NaOCl and CHX. Hydrogen peroxide and lower aqueous ozone concentrations were less effective. Aqueous and gaseous ozone were dose‐ and strain‐dependently effective against the biofilm microorganisms. Total elimination was achieved by high‐concentrated ozone gas (setting 2) and by NaOCl after 1 min or a lower gas concentration (4 g m^?3) after at least 2.5 min. High‐concentrated aqueous ozone (20 μg mL^?1) and CHX almost completely eliminated the biofilm cells, whilst H₂O₂ was less effective. Conclusion High‐concentrated gaseous and aqueous ozone was dose‐, strain‐ and time‐dependently effective against the tested microorganisms in suspension and the biofilm test model.     

Ozone air levels adjacent to a dental ozone gas delivery system

Objective. Ozone (O₃) has been suggested as an anti-microbial treatment in dentistry, with an ozone gas delivery system introduced for the treatment of fissure and root caries. The aim of this study was to investigate the sealing capacity of the novel delivery system and its re-suction capacity during accidental displacement of the cup at different stages of ozone delivery. Material and methods. Ozone leakage was studied in vitro after application on a flat metal surface and on buccal and occlusal tooth surfaces. An ozone analyzer was used to measure ozone gas concentrations adjacent to the delivering cups when adapted to the target surfaces during and after 10–20 s application cycles. The measured levels were compared with the background concentrations in the room. Measurements were performed 1) after complete ozone application cycles, 2) within the cycle before the start of the suction period, and 3) after displacements of the cup during the cycles. Results. Ozone air values varied between 8 and 166 µg·m^?3 for the flat metal surface and between 0 and 108 µg·m^?3 for the tooth surfaces. Ozone leakage levels were 7.6 µg·m^?3 for the flat and 7.4 µg·m^?3 and 5.6 µg·m^?3 for the buccal and occlusal surfaces, respectively, and 5.2 µg·m^?3 and 9.8 µg·m^?3 for the premolar and molar surfaces, respectively. Cycles with displacement showed significantly higher leakage levels than continuous complete cycles (p=0.03). Conclusions. Ozone application cycles with displacements showed significantly higher leakage levels than continuous complete cycles. The largest ozone delivery cups showed the highest leakage values. A change in background levels was seen with similar change in adjacent ozone levels. The overall measured ozone leakage values were low after normally functioning delivery cycles and after repeated displacements. The delivery system can be considered safe.     

Effect of ozone and Tooth MousseTM on the efficacy of peroxide bleaching

Background:  The aim of this in vitro study was to investigate the effect of Tooth Mousse™ (TM) and ozone on the bleaching effectiveness of peroxide (P).
Methods:  Sixty enamel specimens were stained by tea infusion. P (8% carbamide peroxide solution) and the P/TM (50:50) blend were prepared freshly as required. The specimens were divided randomly into six groups: Group A – ozone followed by P; Group B – ozone concurrently with P; Group C – P alone; Group D – ozone followed by P/TM; Group E – ozone concurrently with P/TM; and Group F – P/TM alone. Ozone exposure was of 40 seconds duration. Digital photographic images were recorded at baseline and endpoint under standardized lighting and desiccation conditions. CIELAB L*a*b* values were determined.
Results:  The addition of TM to P or the application of ozone with P did not significantly affect bleaching effectiveness compared with P alone. The application of ozone prior to P significantly decreased bleaching effectiveness as indicated by the ΔL*, Δa*, ΔE and %L* values. The addition of TM to the P did enhance the aesthetic by increasing the lustre and translucency of the treated enamel.
Conclusions:  The results of this study suggest that Tooth Mousse may be applied concurrently with the bleach, and not reduce bleaching effectiveness.     

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.     

The inability of Streptococcus mutans and Lactobacillus acidophilus to form a biofilm in vitro on dentine pretreated with ozone

Background: The use of ozone therapy in the treatment of dental caries is equivocal. The aim of this study was to use an in vitro model to determine the effects of prior ozone application to dentine on biofilm formation and to measure any associated reduction in bacteria viability. Methods: Twenty dentine discs were bonded to the bases of 5 mL polycarbonate screw top vials. Ten dentine discs were infused with ozone for 40 seconds, 10 samples remained untreated as a control. The vials were filled with nutrient medium, sterilized and placed into the outflow from a continuous chemostat culture of Streptococcus mutans and Lactobacillus acidophilus for four weeks. At the conclusion of the experiment bacterial growth was monitored by taking optical density readings of the growth medium in each vial and the outer surface of the dentine specimens were examined by scanning electron microscopy as shown by SEM analysis. Results: Ozone infusion prevented biofilm formation on all the treated samples while there was substantial biofilm present on the control specimens. While the average optical density of the control specimens was almost twice that of the ozone infused dentine (0.710 for the control with a SD of 0.288 and 0.446 for the ozonated samples with a SD of 0.371), the results were not significant (p > 0.05). Conclusions: This preliminary study has shown that the infusion of ozone into non‐carious dentine prevented biofilm formation in vitro from S. mutans and L. acidophilus over a four‐week period. The possibility exists that ozone treatment may alter the surface wettability of dentine through reaction with organic constituents.