Prevention of the ingress of a known virulent bacterium into the root canal system by intracanal medications. Intracanal medications versus placebo in reducing postoperative endodontic pain--a double-blind randomized clinical trial. Effects of instrumentation, irrigation and dressing with calcium hydroxide on infection in pulpless teeth with periapical bone lesions. Flare-ups incidence and severity after using calcium hydroxide as intracanal dressing. Influence of calcium hydroxide intracanal dressings on the prognosis of teeth with endodontically induced periapical lesions. Antibiofilm efficacy of silver nanoparticles as a vehicle for calcium hydroxide medicament against Enterococcus faecalis. Incidence of postoperative pain after use of calcium hydroxide mixed with normal saline or 0.2% chlorhexidine digluconate as intracanal medicament in the treatment of apical periodontitis A clinical evaluation of one and two-appointment root canal therapy using calcium hydroxide. Antimicrobial effect of 0.2% chlorhexidine in infected root canals. Bacterial reduction with nickel-titanium rotary instrumentation. Reduction in intracanal bacteria during root canal preparation with and without apical enlargement. Clinical efficacy of treatment procedures in endodontic infection control and one year follow-up of periapical healing. Comparative evaluation of pH and antibacterial effect of various calcium hydroxide combinations on E. faecalis and its effect on root strength: An in vitro study The effect of medicaments used in endodontic regeneration technique on the dislocation resistance of mineral trioxide aggregate to root canal dentin. Outcome of one-visit and two-visit endodontic treatment of necrotic teeth with apical periodontitis: a randomized controlled trial with one-year evaluation. Antibacterial efficacy of MTAD final rinse and two percent chlorhexidine gel medication in teeth with apical periodontitis: a randomized double-blinded clinical trial. Calcium hydroxide as an intracanal medication: effect on posttreatment pain.
Contamination of the root canal system by persistent , enteric bacteria via leakage through interim restorations has been well documented . This in vitro study evaluated the ability of interappointment medications to prevent contamination of the root canal system by Enterococcus faecalis . Coronally unsealed , medicated tooth roots fixed in a closed system were contaminated daily with a st and ardized , aerobic , broth culture of E. faecalis . Four medications were evaluated ( n = 15 ) : group A , calcium hydroxide/methylcellulose paste ; group B , camphorated parachlorophenol/calcium hydroxide paste ; group C , 1 % chlorhexidine/methylcellulose gel ; and group D , calcium hydroxide points . The mean number of days to contamination as indicated by turbidity in the closed system was the following : group A , 37 ; group B , 46 ; group C , 16 ; group D , 5 ; and a positive control ( no medication ) , 3 . A one-way analysis of variance with a Scheffe post hoc test ( p = 0.05 ) detected significant differences in effectiveness with A and B superior to C and D , and C superior to This prospect i ve r and omized , double-blind factorial study aim ed to compare the efficacy of three different intracanal medicaments with the placebo in controlling the postoperative pain after complete root canal preparation . The study was performed on 64 m and ibular molars of 64 patients with diagnosis of pulp necrosis and acute apical periodontitis . After chemomechanical procedures using the stepback technique and 1 % sodium hypochlorite , the teeth were r and omized into four treatment groups ( n=16 ) . In group I , canals were filled with calcium hydroxide paste mixed with 2 % chlorhexidine gel , group II received 2 % chlorhexidine gel , group III was treated with calcium hydroxide paste , and group IV received no dressing ( control ) . Before dismissal , preoperative pain experience was recorded using a visual analog pain scale . Patients were then instructed to quantify the degree of pain experienced 4h after treatment and daily for a further 24 , 48 , 72 and 96h . Two-way repeated measures ANOVA test and post hoc Tukey 's HSD test revealed that at each time interval groups I and II were significantly more effective in reducing the postoperative pain values than groups III and IV ( p<0.05 ) . Dunnett 's test showed that groups I and II differed significantly from control whereas difference between group III and control was not significant ( p>0.05 ) . Patients with pulp necrosis and acute apical periodontitis that had been dressed with chlorhexidine alone and calcium hydroxide plus chlorhexidine gave rise to less pain than that experienced by patients who had a calcium hydroxide dressing alone or no dressing at all AIM The aim of this study was to evaluate the fate of microorganisms in root canals of teeth with infected pulps and periapical bone lesions with and without the use of calcium hydroxide medication . METHODOLOGY Endodontic sample s were cultured and microorganisms were counted and identified in 43 teeth before ( sample 1 ) and after ( sample 2 ) treatment during the first visit and before ( sample 3 ) and after ( sample 4 ) treatment during the second visit . In the first visit teeth were instrumented and half of the teeth were filled with a thick slurry of calcium hydroxide in sterile saline . The other teeth were obturated with gutta-percha and AH-2 6 sealer . After 4 weeks the teeth with calcium-hydroxide were accessed again and after microbiological sampling they were obturated with gutta-percha and AH-26 sealer . RESULTS The mean total colony forming unit ( CFU ) counts of positive sample s dropped significantly as a result of canal preparation during the first visit from 1.0 x 10(6 ) to 1.8 x 10(3 ) ( between sample s 1 and 2 ) but increased to 9.3 x 10(3 ) in the period between the two visits ( sample 2 and 3 ) . There was no difference in mean total CFU counts of positive sample s between the end of the first ( sample 2 ) and the end of the second visit ( sample 4 ) . The most frequently isolated species were Prevotella intermedia , Capnocytophaga spp .. Actinomyces odontolyticus . Propionibacterium acnes and Peptostreptococcus micros . CONCLUSIONS Although a calcium hydroxide paste was placed in the prepared canals , the number of positive canals had increased in the period between visits . However , the number of microorganisms had only increased to 0.93 % of the original number of CFU ( sample 1 ) . It is concluded that a calcium hydroxide and sterile saline slurry limits but does not totally prevent regrowth of endodontic bacteria Acute pain and swelling following endodontic treatment are a challenge for both the patient and the dentist . According to previous studies , the incidence of flare-ups increases after endodontic treatment of teeth with necrotic pulps . Calcium hydroxide is currently used as a multi- purpose drug in root canal therapy . The aim of this study was to evaluate the incidence and severity of flare-ups after treatment of pulpless teeth using calcium hydroxide as an intracanal dressing .  Sixty patients with single-root necrotic teeth participated in this study . These patients were r and omly divided into three groups of 20 . The patients were treated in Group A in a single-visit approach , in group B with a two-visit approach without any intracanal dressing and group C with a two-visit approach using calcium hydroxide as an intracanal dressing for one week . All of the patients were followed for 72 hours after each treatment session . The information about the incidence and severity of pain and swelling was recorded in tables , using a modified Visual Analogue Scale for pain severity measurement and a scale with four degrees for measuring the severity of swelling . The data were analyzed by chi-square test and GENMODE procedure AIM This prospect i ve clinical study explored the influence of calcium hydroxide as an interappointment dressing on the healing of periapical lesions associated with pulpless teeth that had not been endodontically treated previously . This was achieved by comparing the prognosis after a two-visit root canal treatment with that following a one-visit treatment . METHODOLOGY Seventy-three patients were recruited having one tooth with an endodontically induced lesion . Of these patients , 67 could be re-examined .  Calcium hydroxide was placed in the instrumented root canals of 31 teeth for at least one week and the treatment finished at the second visit . Thirty-six teeth were root canal treated at one visit . The criteria for success were the absence of signs and symptoms indicating an acute phase of periapical periodontitis and radiographically a periodontal ligament space of normal width . Methods for event time analysis were used to evaluate and compare the prognosis of both treatment approaches . RESULTS The probability that complete periapical healing will take place increased continuously with the length of the observation period . In both treatment groups the likelihood that the root canal treatment yields a success within an observation time of five years exceeded 90 % . A statistically significant difference between the two treatment groups could not be detected . CONCLUSIONS From a microbiological perspective , one-visit root canal treatment created favourable environmental conditions for periapical repair similar to the two-visit therapy when calcium hydroxide was used as antimicrobial dressing . One-visit root canal treatment is an acceptable alternative to two-visit treatment for pulpless teeth associated with an endodontically induced lesion OBJECTIVES The aim of the present study was to investigate antibacterial characteristic and Enterococcus faecalis ( E. faecalis ) biofilm suppression effect of different vehicles of calcium hydroxide as intracanal medicaments in short and long-term . METHODS Fifty-four human single-root teeth were contaminated with E. faecalis bacteria . The teeth were r and omly divided into three experimental ( n=16 ) and one control group ( n=6 ) . Each group was then exposed to various intracanal medicaments , namely calcium hydroxide paste ( group 1 ) , calcium hydroxide with chlorhexidine ( group 2 ) , calcium hydroxide with silver nanoparticles suspension ( AgNPs ) ( group 3 ) , and saline as the control group ( group 4 ) . Cultures were made from each group after one week and one month , and the number of colonies was counted . Moreover , a sample of each group was examined under electron microscope . Kruskal-Wallis test served for inter-group comparisons , and Mann-Whitney test served for comparison between the two incubation periods . RESULTS All the intracanal medicaments result ed in significant decrease in number of colonies compared to control group in both incubation periods . After one week , the mixture of calcium hydroxide and AgNPs was the most effective medicament against E. faecalis bacteria ( p<.05 ) . No significant difference in antibacterial effect of the medicaments existed after one month incubation period ( p>.05 ) . CONCLUSION AgNPs was more effective on the E. faecalis biofilm than other tested vehicles in short-term medication . CLINICAL SIGNIFICANCE AgNPs seems to have a good potential to be used as an appropriate vehicle of calcium hydroxide in order to eliminate of E. faecalis biofilm from human dentine in short-term Objective To compare the incidence of postoperative pain after the use of calcium hydroxide powder mixed with normal saline or 0.2 % chlorhexidine digluconate as intracanal medicament . Participants Fifty-five subjects aged 17–60 years with teeth diagnosed to have apical periodontitis . Intervention Two-visit conventional root canal treatment of seventy teeth . The teeth were divided by r and omization ( balloting ) into two groups : control group and experimental group , each with thirty-five teeth treated with calcium hydroxide mixed with normal saline or with 0.2 % chlorhexidine digluconate as intracanal medicament respectively . Incidence of postoperative pain was assessed using the universal pain assessment tool and whether or not analgesic was taken . Main outcome measured Incidence of post-operative pain . Result Postoperative pain occurred only at 1-day and 1-week review s. In the control group , the overall incidence of pain was the same at both review periods ( 5.7 % ) , while the experimental group showed a slight decrease in incidence between 1-day ( 17.2 % ) and 1-week ( 11.4 % ) review s. Incidence of flare-ups was more in the experimental group ( 11.4 % ) than in the control group ( 5.7 % ) . No significant statistical differences between the two groups were observed ( p > 0.05 ) . Conclusion The incidence of postoperative pain was lower in the normal saline treatment group , but the difference was not statistically significant A clinical study using vital maxillary central incisors was performed to evaluate the incidence of postoperative pain after root canal treatment in one- or two-appointments using a calcium hydroxide-containing root canal sealer . No differences were observed between the two groups The aim of this study was to identify bacteria from the infected root canals of teeth with chronic apical periodontitis , and to evaluate the antibacterial effect of 0.2 % chlorhexidine ( CHX ) , as an irrigant , in reducing the microbial flora 48h after root canal preparation . A total of 44 subjects were r and omly divided in the experimental group and the control group . The first bacterial sample s from all root canals were obtained in the beginning , before any treatment . During mechanical instrumentation , root canals were irrigated three times , with 0.2 % CHX in the experimental group , and with saline solution in the control group . All canals were dried and temporarily sealed with zinc oxide-sulfate cement . After 48 h the second sample s were obtained . Bacterial sample s were subjected to microbiologic processing . The study indicates that 0.2 % CHX is significantly effective in reducing the microbial flora , and could be used as an irrigant solution The purpose of this study was to compare intracanal bacterial reduction on teeth instrumented with 0.04 tapered nickel-titanium ( NiTi ) rotary instrumentation to bacterial reduction when using a stainless-steel K-file step-back technique using sterile saline irrigation .  Forty-eight patients with apical periodontitis were r and omly assigned treatment type . The canals were sample d before , during , and after instrumentation . The sample s were incubated anaerobically for 7 days at 37 degrees C , colony-forming unit numbers calculated , and a log transformation performed to normalize the counts . Teeth exhibiting apical periodontitis were uniformly infected , whereas vital control teeth were not . A similar and uniform reduction occurred with progressive filing , regardless of technique ( p < 0.0001 ) . There was no detectable difference in colony-forming unit count after NiTi rotary or stainless-steel h and instrumentation ( p = 0.42 ) . Neither technique could predictably render canals free of bacteria . The results of this study indicate NiTi rotary and stainless-steel h and K-file step-back instrumentation techniques were not significantly different in their ability to reduce intracanal bacteria AIM To compare in vitro intracanal bacterial reduction using nickel-titanium rotary instruments with and without apical enlargement . METHODOLOGY Thirty-eight palatal roots of maxillary molar teeth , with mature apices were subdivided according to lengths and then r and omly assigned to two experimental and one control groups . The roots were sterilized and then reinfected with Enterococcus faecalis , which served as a bacteriological marker . All roots in the experimental groups were prepared in a step-down sequence with engine-driven GT rotary files at 350 rpm . In experimental group A ( n = 16 ) additional apical enlargement to ISO size 35 was performed . In group B ( n = 16 ) a serial step-back technique was followed with no apical enlargement . This was combined in groups A and B with irrigation with NaOCl and EDTA . In the control group ( group C , n = 6 ) irrigation only was carried out , with no mechanical preparation . Sample s were then taken from the root canals to determine the numbers of remaining bacteria . RESULTS In groups A and B , 15 ( 94 % ) and 13 ( 81 % ) specimens were rendered bacteria-free , respectively . In the control group C none of the specimens were bacteria-free . There was a significant difference ( P < 0.001 ) in the antibacterial effects of experimental and control regimens . There was , however , no significant difference ( P = 0.276 ) between the preparation methods used in the experimental groups . CONCLUSIONS There was no significant difference in intracanal bacterial reduction when Ni-Ti GT rotary preparation with NaOCl and EDTA irrigation was used with or without apical enlargement preparation technique . It may therefore not be necessary to remove dentine in the apical part of the root canal when a suitable coronal taper is achieved to allow satisfactory irrigation of the root canal system with antimicrobial agents The objective was to evaluate the clinical efficacy of chemomechanical preparation of the root canals with sodium hypochlorite and interappointment medication with calcium hydroxide in the control of root canal infection and healing of periapical lesions .  Fifty teeth diagnosed with chronic apical periodontitis were r and omly allocated to one of three treatments : Single visit ( SV group , n = 20 ) , calcium hydroxide for one week ( CH group n = 18 ) , or leaving the canal empty but sealed for one week ( EC group , n = 12 ) . Microbiological sample s were taken to monitor the infection during treatment . Periapical healing was controlled radiographically following the change in the periapical index at 52 wk and analyzed using one-way ANOVA . All cases showed microbiological growth in the beginning of the treatment . After mechanical preparation and irrigation with sodium hypochlorite in the first appointment , 20 to 33 % of the cases showed growth . At the second appointment 33 % of the cases in the CH group revealed bacteria , whereas the EC group showed remarkably more culture positive cases ( 67 % ) .  Sodium hypochlorite  was effective also at the second appointment and only two teeth remained culture positive . Only minor differences in periapical healing were observed between the treatment groups . However , bacterial growth at the second appointment had a significant negative impact on healing of the periapical lesion ( p < 0.01 ) . The present study indicates good clinical efficacy of sodium hypochlorite irrigation in the control of root canal infection . Calcium hydroxide dressing between the appointments did not show the expected effect in disinfection the root canal system and treatment outcome , indicating the need to develop more efficient inter-appointment dressings Aim : To evaluate and compare the pH and antibacterial property of Ca(OH)2 combined with iodine potassium iodide ( IKI ) or chlorhexidine ( CHX ) on E. faecalis and to assess and compare their effect on fracture resistance of root dentin . Material s and Methods : CHX ( 0.5 % ) The following test material s were used : Group I Calcium hydroxide + saline , Group II Calcium hydroxide + CHX ( 0.5 % ) and Group III Calcium hydroxide + IKI ( 2 % ) . For antibacterial activity , 60 root dentin blocks ( 20 in each group ) were infected by E. faecalis followed by placement of medicaments . At the end of 24 h and 7 days , 10 sample s from each group were r and omly chosen and assessed for antibacterial activity . For evaluation of root strength , 30 teeth were used and stored in sterile saline after placement of medicament . At the end of 30 days , sample s were subjected to fracture resistance testing on the Universal Strength Testing Machine . Hounsfield strength testing machine , UK pH of the various calcium hydroxide combinations was determined with a digital pH meter . Statistical analysis : Kruskal Wallis test , Mann Whitney U test , and one-way ANOVA test for intergroup comparison and Wilcoxon 's signed rank test and student 's paired t test for intragroup comparison . Results : Group III showed significantly greater antibacterial activity against E. faecalis , followed by group II and control group . There was no statistically significant change in the pH and root strength values among all the groups . Conclusion : The present study revealed that IKI or CHX in combination with Ca(OH)2 is an effective medicament against E. faecalis INTRODUCTION The aim of this study was to evaluate the effect of calcium hydroxide ( CH ) and antibiotic pastes , including a mixture of metronidazole and ciprofloxacin , with and without minocycline or cefaclor , on the dislocation resistance of mineral trioxide aggregate ( MTA ) to root dentin . METHODS Eighty single-rooted human m and ibular premolars were selected . The teeth were prepared by using the ProTaper system . The prepared teeth were then instrumented to a # 6 Peeso reamer to obtain a st and ard internal diameter of 1.5 mm . The reamers were passed 1 mm beyond apex to simulate immature teeth . The specimens were then r and omly divided into a control group ( no intracanal medicament was used ) and 4 experimental groups that were treated with an intracanal medicament : CH , double antibiotic paste ( DAP ) with metronidazole and ciprofloxacin , triple antibiotic paste ( TAP ) with minocycline , or TAP with cefaclor ( n = 16 ) . After 3 weeks , the medicaments were removed , and approximately 3 mm of MTA was placed in the coronal third of the canals . A push-out test was used to measure the dislocation resistance between the root dentin and MTA . Data were analyzed by using one-way analysis of variance and Tukey post hoc tests . RESULTS The dislocation resistance values of the CH , TAP with minocycline , and TAP with cefaclor groups were similar to those of the control group ( P > .05 ) , whereas the DAP group had the lowest dislocation resistance when compared with the other groups ( P < .05 ) . Overall , there was a predominance of cohesive failures between root dentin and MTA . CONCLUSIONS The results of this study indicate that the application of DAP as an intracanal medicament reduced the dislocation resistance of MTA to root dentin The choice of one-visit versus two-visit root canal therapy for necrotic teeth with apical periodontitis is a source of current debate . The primary objective of this r and omized controlled clinical trial was to compare radiographic evidence of periapical healing after root canal therapy completed in one visit or two visits with an interim calcium hydroxide/chlorhexidine paste dressing .  Ninety-seven patients met the inclusion criteria and consented to participate in this study . Patients were r and omly assigned to either the one-visit or two-visit group , and root canal therapy was performed with a st and ardized protocol . Patients in the two-visit group received an intracanal dressing of calcium hydroxide/chlorhexidine paste . Sixty-three patients , 33 in the one-visit group and 30 in the two-visit group , were evaluated at 12 months . The primary outcome measure was change in apical bone density by using the periapical index ( PAI ) . Secondary outcome measures were proportion of teeth healed or improved in each group . Both groups exhibited equally favorable periapical healing at 12 months , with no statistically significant differences between groups INTRODUCTION Clinical assessment of the efficacy of novel root canal disinfection protocol s is an important focus in endodontic research . This r and omized double-blinded study assessed the antibacterial efficacy of a final rinse with BioPure MTAD ( MTAD ) and intracanal medication with 2 % chlorhexidine gel ( CHX ) in teeth with apical periodontitis . METHODS Canals in 30 teeth ( single-rooted and multi-rooted ) were prepared by using 1.3 % NaOCl , rinsed with MTAD or saline in r and om sequence , medicated with CHX for 7 days , irrigated with 1.3 % NaOCl , and filled . Bacteriologic root canal sample s were obtained by aspiration before ( 1A ) and after ( 1B ) canal preparation , after the final rinse ( 1C ) , after CHX was flushed ( 2A ) , and after final irrigation ( 2B ) . Bacteria were enumerated by epifluorescence-microscopy ( EFM ) by using 2 staining methods and by colony-forming-unit ( CFU ) counts after 14 days of incubation . RESULTS Bacterial counts ( EFM ) in 1B were greater than 95 % decreased from 1A . Low bacterial densities in 1B , 1C , 2A , and 2B did not differ significantly from each other . EFM counts were consistently higher than CFU counts . CONCLUSIONS The final rinse with MTAD and medication with CHX did not reduce bacterial counts beyond levels achieved by canal preparation with NaOCl Calcium hydroxide is advocated as an intracanal medication for various purpose s , including prevention of posttreatment symptoms . This study assessed whether calcium hydroxide had a pain-controlling effect at different times when compared with no intracanal medication . One hundred forty patients participated . Conditions diagnosed were pulp/periapical pathosis with or without symptoms . At least partial cleaning and shaping was completed . At r and om , either Ca(OH)2 plus H2O paste or a dry cotton pellet was placed in the canals of half the teeth , respectively . All teeth were temporized with Intermediate Restorative Material . Patients assessed posttreatment  pain up to 48 h as none , mild , moderate , or severe . The pain levels in each test group [ Ca(OH)2 versus cotton pellet ] at each time period were compared statistically with a multiple-regression analysis . There was no significant difference in posttreatment pain between the two groups at any time period or with any diagnosis or symptom . The use of calcium hydroxide as an intracanal medication was unrelated to the incidence and /or severity of posttreatment pain
Calcium hydroxide has limited effectiveness in eliminating bacteria from human root canal when assessed by culture techniques
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 ) .