Clinical efficacy of an endodontic antiseptic in a controlled release delivery system

Abstract The purpose of this clinical study was to assess the bacteriological status of the root canal after disinfection with a quaternary ammonium compound in a controlled release delivery system. Fifty-three teeth with apical periodontitis as evidenced by periapical radiolucencies were used. Under aseptic conditions the root canals were completely instrumented and irrigated with sodium hypochlorite. After the instrumentation, 38 teeth were treated with the quaternary ammonium compound in the controlled release dispenser; 15 teeth were treated with formocresol. Bacteriological samples from the root canals were taken after 7 days using an anaerobic technique. The results indicated that the quaternary ammonium compound in controlled release was as effective as formocresol in obtaining bacteria-free root canals. The advantages of an antiseptic with a long lasting effect for the elimination of bacteria from the root canal and for the prevention of reinfection were emphasized.     

Controlled release of medicaments in endodontic therapy

Abstract It was the purpose of this investigation to study the suitability of a controlled release delivery system for endodontic medicaments, making it possible to maintain a constant concentration of a medicament in the root canal for an extended period of time. The delivery system comprised an inner core matrix containing the medicament surrounded by a polymeric membrane allowing a controlled release of the active ingredient. Controlled release preparations containing formocresol, camphorated paramonochlorphenol, Creation, and a quaternary ammonium compound (dodecyl-dimethyl-benzylammonium chloride) were manufactured and applied to root canals of dogs' teeth. In control experiments the same medicaments were applied to root canals by means of cotton pellets. After 1, 3, 7 and 45 clays the pieces of polymeric materials and the cotton pellets were removed from the root canals and tested for antibacterial effect. After 1 d in the root canal none of the medicaments on cotton pellets had an effect. Of the controlled release preparations, the quaternary ammonium compound had a fairly constant effect on bacterial growth for the duration of the experiment (45 d). The results suggested that the idea of improving the effect of endodontic medicaments by means of controlled release delivery systems is valid, and may gain clinical importance in the future.     

氢氧化钙应用于根管封药的临床研究

目的：观察氢氧化钙甘油糊剂用于根管封药的临床疗效。方法：选择244例慢性根尖周炎病例，随机分观察组（氢氧化钙甘油糊剂组）124例、 对照组（甲醛甲酚组）120例，观察封药一周后的临床疗效和细菌培养结果。结果：两组的临床效果有显著差异（P＜0．01）。Ca(OH2)组67．7％一次封药后即可行根管充填，FC组为40％，Ca(OH2)组治疗期间未产生疼痛，FC组则有8．3％产生疼痛，平均封药次数Ca(OH2)组1．38次，FC组1．76次，细菌培养结果与此呈正相关。结论：氢氧化钙甘油糊剂在杀灭微生物、减少治疗期间疼痛和 减低对根尖周组织和刺激性方面效果优良。     

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目的对比观察氢氧化钙和甲醛甲酚用于根尖周炎患牙根管内封药的疗效。方法选择2008年1月到2009年12月在中国医学科学院整形外科医院口腔中心就诊的135例牙根尖周炎患者的156颗患牙,随机分为A组(81颗)和B组(75颗)。步退法根管预备后分别于根管内封入氢氧化钙(A组)和甲醛甲酚(B组)进行消毒。于封药后1周、根充后1周和治疗后3个月对两组疗效进行观察并作出相应评价。结果根管封药后1周A组的有效率为92.59%,B组的有效率为78.67%,两组间差异有统计学意义(P<0.05);根管充填后1周,A、B两组的急症发生率(3.70%对12.0%)差异有统计学意义(P<0.05)。治疗后3个月A组的成功率为91.36%;B组为84.00%,两组间差异有统计学意义(P<0.05)。结论氢氧化钙用于根尖周炎患牙根管内消毒的疗效优于甲醛甲酚。     

氯已啶控释系统根管消毒作用的实验动物研究

对氯已啶控释系统的根管消毒作用进行了实验动物研究，发现将该药物封入髓腔７ｄ后，细菌学培养均为阴性，并能稳定地保持抑菌状态；统计学分析，其效果明显优于对照组。提示氯已啶控释系统是一种有效的根管消毒剂。     

The comparative antimicrobial effect of calcium hydroxide

The antimicrobial effectiveness of calcium hydroxide, camphorated paramonochlorophenol, and formocresol in root canals of extracted human teeth was compared. Canals in single-rooted teeth were enlarged and inoculated with Streptococcus mutans, Actinomyces viscosus, and Bacteroides gingivalis or Bacteroides fragilis. After treatment with a test agent and sealing and incubation for 1 hour, the canal contents were analyzed for the number of viable test bacteria and compared with that of inoculated teeth not treated with test agents. All test agents exhibited antimicrobial activity against all bacteria, with percent reductions in viable bacteria ranging from 64.3% to 100%. The combined data for Pulpdent paste and calcium hydroxide showed significantly higher antimicrobial activity than the combined data for camphorated paramonochlorophenol and formocresol for S. mutans and B. gingivalis or B. fragilis but showed no difference for A. viscosus.     

Tissue response to a quaternary ammonium compound in a controlled release delivery system

Abstract The suitability of various antiseptic agents for use in a controlled release delivery system has recently been evaluated for use in endodontic therapy. Of the medicaments tested, a quaternary ammonium compound, dodecyl-dimethyl benzyl ammonium chloride, was found to be well suited for inclusion in the controlled release preparation. The purpose of this study was to evaluate the tissue response to the quaternary ammonium compound in the controlled release delivery system. For the purpose of comparison, formocresol, Cresatin® and eugenol were included in the study. The tissue-irritating effect was assessed by incubating muscle tissue that had been in contact with the antiseptics for the demonstration of succinate dehydrogenase activity. Medicaments with a tissue-irritating effect caused a zone of inhibited enzyme activity in the tissue-medicament contact areas. The quaternary ammonium compound in the controlled release delivery system was the least irritating of the medicaments tested and caused minimal inhibition of enzyme activity.     

Preliminary clinical study of endodontic antiseptic in monotithic type chlorhexidine controlled release delivery system]

The purpose of clinical study was to assess the bacteriological status of the root canal after disinfection with the monotithic type chlorhexidine enrolled release delivery system (CCROS).In experiments the monotithic type CCRDS was found to be more effective than the reservoir type CCRDS.The root canals of 24 teeth with apical periodontitis were completely instrumented and irrigated with sodium hypochloride.After the instrumentations,12 teeth were treated with the monotitihic type CCRDS,12 teeth were treated with formocresol.Bacterological samples from the root canals were taken after 5 days using an anaerobic technique.The results indicated that monotithic type CCRDS was more effective than formocresol in obtaining bacteria-free root canals(Chi-square test P<0.05).The advantages of an antiseptic with along lasting effect for the elimination of bacteria form the root canal and for the prevention of reinfection were emphasized.     

常用根管消毒药物对犬牙根管内优势致病菌消毒作用研究

目的:对比研究碘仿糊剂、FC、Vitapex和氢氧化钙糊剂4种根管消毒药物对犬牙根管内根尖周病优势致病菌的抗菌活性。方法:健康成年杂种犬4只,随机选取单根管前牙,建立犬牙根尖周病模型。取根管预备前后根管内细菌进行培养和计数,将碘仿糊剂、FC、Vitapex、氢氧化钙糊剂分别封入4组根管内,对照组封无菌纸捻,7 d后再取样进行细菌培养和计数,对细菌计数结果进行统计学分析。结果:①根管预备后的各种细菌数量均较根管预备前明显减少,差异有统计学意义(P<0.05);②封药后根管内细菌数量大部分为0,但4种消毒药物抗菌活性比较无显著统计学意义(P>0.05)。结论:完善的根管预备能有效去除大部分根管内优势致病菌,4种消毒药物对犬牙根管内的优势致病菌均有抗菌作用。     

Experimental apexigenesis in baboons

Abstract Apexification with calcium hydroxide is a routine procedure. However, some clinical reports suggest that root completion can occur by controlling the infection without use of a catalyst. The present study investigated the use of tetracycline treatment (in root canals) on root growth in immature teeth, rendered non-vital experimentally. Incisors in 3 young baboons were exposed and canals were left open. After 2 months all canals were cleaned and treated with either tetracycline or formocresol. Some canals in each group were filed. Animals were sacrificed after 6 months. Bacterial evaluations were done before placing medications, one week later and six months after that. The number of bacteria were reduced in all treatment groups. Root growth almost near completion was observed in more teeth treated with tetracycline than in the formocresol group.     

地塞米松-氢氧化钙糊剂用于根管封药的临床研究

目的 观察地塞米松-氢氧化钙糊剂应用于根管封药的临床疗效。方法 选择240例根尖周炎病例，随机分观察组(地塞米松-氢氧化钙糊剂组)对照组(甲醛甲酚组)各120例，观察封药一周后的临床疗效。结果 两组效果有显著差异，地塞米松-氢氧化钙糊剂根管封药显效率(90．8％)优于甲醛甲酚根管封药(66．7％)。结论 地塞米松-氢氧化钙糊剂应用于根管封药能有效预防和降低根管治疗期间疼痛和水肿的发生。     

Biofilm formation in medicated root canals

The hypothesis that Enterococcus faecalis resists common intracanal medications by forming biofilms was tested. E. faecalis colonization of 46 extracted, medicated roots was observed with scanning electron microscopy (SEM) and scanning confocal laser microscopy. SEM detected colonization of root canals medicated with calcium hydroxide points and the positive control within 2 days. SEM detected biofilms in canals medicated with calcium hydroxide paste in an average of 77 days. Scanning confocal laser microscopy analysis of two calcium hydroxide paste medicated roots showed viable colonies forming in a root canal infected for 86 days, whereas in a canal infected for 160 days, a mushroom-shape typical of a biofilm was observed. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis showed no differences between the protein profiles of bacteria in free-floating (planktonic) and inoculum cultures. Analysis of biofilm bacteria was inconclusive. These observations support potential E. faecalis biofilm formation in vivo in medicated root canals.     

Microbial culture and checkerboard DNA-DNA hybridization assessment of bacteria in root canals of primary teeth pre- and post-endodontic therapy with a calcium hydroxide/chlorhexidine paste

International Journal of Paediatric Dentistry 2011 Aim. To investigate the root canal microbiota of primary teeth with apical periodontitis and the in vivo antimicrobial effects of a calcium hydroxide/chlorhexidine paste used as root canal dressing. Design. Baseline samples were collected from 30 root canals of primary teeth with apical periodontitis. Then, the root canals were filled with a calcium hydroxide paste containing 1% chlorhexidine for 14 days and the second bacteriologic samples were taken prior to root canal filling. Samples were submitted to microbiologic culture procedure to detect root canal bacteria and processed for checkerboard DNA–DNA hybridization. Results. Baseline microbial culture revealed high prevalence and cfu number of anaerobic, black‐pigmented bacteroides, Streptococcus, and aerobic microorganisms. Following root canal dressing, the overall number of cfu was dramatically diminished compared to initial contamination (P <0.05), although prevalence did not change (P > 0.05). Of 35 probes used for checkerboard DNA–DNA hybridization, 31 (88.57%) were present at baseline, and following root canal dressing, the number of positive probes reduced to 13 (37.14%). Similarly, the number of bacterial cells diminished folowing application of calcium hydroxide/chlorhexidine root canal dressing (P = 0.006). Conclusion. Apical periodontitis is caused by a polymicrobial infection, and a calcium hydroxide/chlorhexidine paste is effective in reducing the number of bacteria inside root canals when applied as a root canal dressing.     

The antibacterial effect of camphorated paramonochlorophenol, camphorated phenol and calcium hydroxide in the treatment of infected root canals

Abstract The bactericidal efficacy of calcium hydroxide, camphorated phenol and camphorated paramonochlorophenol as intracanal dressings was evaluated clinically when the root canals of 65 single-rooted teeth with periapical lesions were treated. A bacteriological technique that could detect even small numbers of anaerobic bacteria in the canals was used. After treatment, including intracanal dressing with calcium hydroxide paste (Calasept), bacteria were recovered from one of 35 treated root canals. After use of camphorated phenol or camphorated paramonochlorophenol as the dressing, bacteria were recovered from 10 of 30 treated root canals. The isolated bacteria were predominantly Gram-positive and anaerobic. There was no indication that specific bacteria were resistant to the treatment. The results indicate that the endodontic treatment of infected root canals can be completed in two appointments when calcium hydroxide paste is used as an intracanal dressing.     

ASSOCIATION OF CALCIUM HYDROXIDE AND METRONIDAZOLE IN THE TREATMENT OF DOG'S TEETH WITH CHRONIC PERIAPICAL LESION

One of the primary objectives of endodontic treatment of teeth with pulp necrosis is the elimination of microorganisms from the root canal system, as effectively as possible, especially in cases with chronic periapical lesions. AIM: The purpose of this study was to analyze the response of the periapical tissue of dogs'' teeth with chronic periapical lesions to endodontic treatment performed with utilization of metronidazole, calcium hydroxide, and an association of both as root canal dressings. METHODOLOGY: Forty root canals were submitted to pulpectomy and the root canals were kept exposed to the oral environment for 6 months. Then, they were submitted to biomechanical preparation and divided into 4 study groups with 10 specimens: group I – no root canal dressing; group II – calcium hydroxide; group III – metronidazole; group IV – calcium hydroxide associated to metronidazole. After 15 days, the root canals were filled with Fill Canal sealer. After 90 days, the animals were killed and the especimens processed for histological analysis. RESULTS: Calcium hydroxide dressing provided a significantly better outcome compared to other experimental groups (α = 0.01). Also, the results of the association of metronidazole and calcium hydroxide were similar to those observed for the metronidazole group. The worst results were obtained by the no root canal dressing group. CONCLUSION: The use of metronidazole alone or associated with Calcium hydroxide, did not improve periapical healing when compared to Calcium hydroxide dressing.     

Root canal medicaments

The ultimate goals of endodontic treatment are complete removal of bacteria, their byproducts and pulpal remnants from infected root canals and the complete seal of disinfected root canals. Intracanal medicaments have been thought an essential step in killing the bacteria in root canals; however, in modern endodontics, shaping and cleaning may be assuming greater importance than intracanal medicaments as a means of disinfecting root canals. Until recently, formocresol and its relatives were frequently used as intracanal medicaments, but it was pointed out that such bactericidal chemicals dressed in the canal distributed to the whole body from the root apex and so might induce various harmful effects including allergies. Furthermore, as these medicaments are potent carcinogenic agents, there is no indication for these chemicals in modern endodontic treatment. Today, biocompatibility and stability are essential properties for intracanal medicaments. The more modern meaning of intracanal dressing is for a blockade against coronal leakage from the gap between filling materials and cavity wall. Calcium hydroxide has been determined as suitable for use as an intracanal medicament as it is stable for long periods, harmless to the body, and bactericidal in a limited area. It also induces hard tissue formation and is effective for stopping inflammatory exudates. Single‐visit endodontics, where intracanal medicaments are not used, is generally not now contraindicated and various reports have shown that the clinical outcomes between single‐ and multiple‐ visit endodontics are similar. There is no reason to counsel against single‐visit endodontics: however, if multiple‐visit endodontics is chosen, calcium hydroxide is recommended to be used as an intracanal medicament.     

The antimicrobial effect of calcium hydroxide as a short-term intracanal dressing

The antibacterial effect of calcium hydroxide as a short-term intracanal dressing was clinically evaluated by applying the medicament for 10 minutes or 7 days in root canals of teeth with periapical lesions. The results showed that the 7-day dressing efficiently eliminated bacteria which survived biomechanical instrumentation of the canal, while the 10-minute application was ineffective.     

干髓术失败患牙的根管再治疗

目的:通过对干髓术失败患牙进行根管再治疗,探讨此类病例的特点及再治疗方法.方法:选取干髓术失败的磨牙63个,采用小号K锉配合次氯酸钠溶液和EDTA溶液探查根管并清理根管内的感染物质,封入氢氧化钙糊剂1～2周,采用机动镍钛器械Hero642进行根管预备,侧向加压技术充填根管,记录治疗过程中患牙症状的改善程度,根管疏通情况,根管预备和充填的效果.结果:62个患牙的根管疏通成功,治疗过程中症状明显缓解或完全消失,瘘管明显减小或消失,根管预备时无根管偏移、根尖阻塞、台阶等并发症发生,根管形态良好.结论:干髓术失败患牙在根管治疗时强调彻底清除根管内的感染物质,采用次氯酸钠和EDTA溶液清理根管,氢氧化钙消毒根管,机用镍钛器械进行根管预备能取得良好的治疗效果.     

Antibacterial efficacy of calcium hydroxide intracanal dressing: a systematic review and meta-analysis

AIM: To determine to what extent does calcium hydroxide intracanal medication eliminate bacteria from human root canals, compared with the same canals before medication, as measured by the number of positive cultures, in patients undergoing root canal treatment for apical periodontitis (teeth with an infected root canal system). METHODOLOGY: CENTRAL, MEDLINE and EMBASE databases were searched. Reference lists from identified articles were scanned. A forward search was undertaken on the authors of the identified articles. Papers that had cited these articles were also identified through the Science Citation Index to identify potentially relevant subsequent primary research. REVIEW METHODS: The included studies were pre-/post-test clinical trials comparing the number of positive bacterial cultures from treated canals. Data in those studies were independently extracted. Risk differences of included studies were combined using the generic inverse variance and random effect method. RESULTS: Eight studies were identified and included in the review, covering 257 cases. Sample size varied from 18 to 60 cases; six studies demonstrated a statistically significant difference between pre- and post-medicated canals, whilst two did not. There was considerable heterogeneity among studies. Pooled risk difference was -21%; 95% CI: -47% to 6%. The difference between pre- and post-medication was not statistically significant (P = 0.12). CONCLUSIONS: Calcium hydroxide has limited effectiveness in eliminating bacteria from human root canal when assessed by culture techniques.     

氢氧化钙甘油糊剂对根管壁玷污层的溶解作用研究

目的观察氢氧化钙甘油糊剂对根管壁玷污层的溶解作用。方法30颗离体上前牙随机分为3组。常规预备根管后,A组封入氢氧化钙甘油糊剂,B组封入碘仿糊剂,C组封入樟脑酚。7d后清洗根管壁,并在扫描电镜下观察。结果A组根管壁玷污层明显较少,与B组和C组差异有统计学意义(P<0.01);B组与C组玷污层差异无统计学意义(P>0.05)。结论氢氧化钙甘油糊剂对根管壁玷污层有溶解作用。