Medicaments: aids to success in endodontics. Part 1. A review of the literature

Efficacy of 2% Paradichlorobenzene, 10% Citric Acid, 17% Ethylenediaminetetraacetic Acid, and 0.2% Chitosan at Removing Calcium Hydroxide From the Root Canals

INTRODUCTION

Chronic infections often require the use of an intracanal medicament. Calcium hydroxide is the most commonly used intracanal medicament. However, retrieval of calcium hydroxide (CH) medicaments is a challenge.

AIM

This study evaluated the efficacy of 2% paradichlorobenzene, 10% citric acid, 17% ethylenediaminetetraacetic acid (EDTA), and 0.2% chitosan in removing calcium hydroxide from the root canals.

METHODS AND MATERIALS

Forty single-rooted mandibular premolars extracted for orthodontic reasons were selected for the study. After access opening, cleaning and shaping were performed following a standardized irrigation protocol, and the samples were pre-weighed for baseline weight. CH was placed in canals until the apex, and the specimen was incubated at 37 °C and 100% relative humidity for seven days. These samples were weighed again for quantitative analysis and subjected to cone beam computed tomography (CBCT) for volumetric analysis using ITK SNAP software (Penn Image Computing and Science Laboratory (PICSL), University of Pennsylvania, Philadelphia, PA). The samples were randomly divided into four groups based on the irrigant used for the removal of medicament. Group 1: 2% paradichlorobenzene; group 2: 10% citric acid; group 3: 17% EDTA; and group 4: 0.2% chitosan, all in combination with sonic agitation. After the removal of CH, weight and volumetric analyses were repeated, and the percentage difference was calculated.

STATISTICAL ANALYSIS

Statistical analysis was done using the one-way ANOVA test for both weight and volumetric assessment, and the inter-group comparison was made using the post hoc Tukey test.

RESULTS

The maximum retrieval was observed with 2% paradichlorobenzene by both weight (96.75%) and volumetric (91.42%) assessment, with p=0.00 and p=0.01, respectively. This was followed by 0.2% chitosan, 10% citric acid, and the least, 17% EDTA.

CONCLUSION

Two percent paradichlorobenzene combined with sonic agitation was most efficient in removing CH, followed by 0.2% chitosan, 10% citric acid, and 17% EDTA chitosan.

pH changes in radicular dentine associated with calcium hydroxide and corticosteroid/antibiotic pastes

The aim was to compare hydroxyl ion diffusion through dentine following placement of calcium hydroxide and Ledermix paste. Thirty-six teeth were divided into one control (n = 6) and three experimental (n = 10) groups - (i) Pulpdent paste; (ii) Pulpdent/Ledermix pastes; (iii) Ledermix paste and (iv) Saline. pH was measured in inner and outer dentine cavities over 12 months. Inner dentine time to maximum pH (Tmax ) was 1 week for Pulpdent and 2 weeks for Pulpdent/Ledermix. Pulpdent's outer dentine Tmax was 4 weeks and Pulpdent/Ledermix was 10 weeks. After day 1, Pulpdent pH was higher and this continued for 12 months. Pulpdent's outer dentine pH was higher than Ledermix and controls, but not significantly different from Pulpdent/Ledermix. Pulpdent/Ledermix had significantly higher pH than controls and Ledermix from day 5 until 10 months when Pulpdent/Ledermix outer dentine pH decreased and became similar. In all groups, pH reduced after 3 months.

Comparing the Antifungal Effect of Sodium Hypochlorite Gel versus Different Types of Root Canal Medicaments at Different Time Intervals Using the Agar Diffusion Test: An In Vitro Study

Aims

The purpose of this study was to compare the antifungal activity of sodium hypochlorite gel to those of four intracanal medicaments at various time intervals.

Materials and Methods

The agar well diffusion technique was utilized to test the antifungal activity of the following medicaments against Candida albinans (C. albicans): sodium hypochlorite gel, chlorhexidine gel, calcium hydroxide paste, Ledermix, and Diapex Plus. The inhibition zone related to each medicine was measured in millimeter after 24, 48, and 72 hours of incubation at 37°C. The data were analyzed using one-way ANOVA and Games–Howell tests, at a significance level of P < 0.05.

Results

Except for Ledermix and Diapex Plus, which had no antifungal action, all of the medicaments showed varied inhibitory zones for C. albicans. At all periods, the NaOCl gel had the most significant inhibition zones, followed by the CHX gel and calcium hydroxide. At all time intervals, the NaOCl gel demonstrated comparable antifungal efficacy. When compared to a 24-hour time interval, the CHX gel showed an increased antifungal activity at the 48-hour and 72-hour intervals. Calcium hydroxide, on the other hand, showed a decrease in its antifungal activity at the 72-hour interval.

Conclusion

The antifungal activity of sodium hypochlorite gel was the highest among the investigated medicaments. Chlorhexidine gel's antifungal activity improved over time, whereas calcium hydroxide's antifungal activity declined. Diapex Plus and Ledermix did not have any antifungal properties.

Evaluation of the efficacy of a novel antibiotic-steroid paste versus conventionally used intracanal antibiotic pastes and irrigating solutions against a 3-week-old biofilm of Enterococcus faecalis

Introduction

Intracanal medicaments have been used during endodontic regenerative procedures to eradicate endodontic pathogens.

Aims

The aim of our study was (1) to evaluate the antimicrobial efficacy of a novel antibiotic-steroid paste over the regularly used calcium hydroxide (Ca (OH)₂), double antibiotic paste (DAP), and modified triple antibiotic paste (M-TAP) and (2) to check the antimicrobial efficacy of irrigating solutions, Chlorhexidine (CHX), and sodium hypochlorite (NaOCl) against a 3-week-old Enterococcus faecalis (E. faecalis) biofilm.

Materials and Methods

A total of 112 human extracted teeth were contaminated with E. faecalis for a period of 21 days. A novel antibiotic-steroid paste, Ca (OH) ₂, DAP, M-TAP, and a placebo were placed inside the canal, sealed, and incubated in an aerobic environment at 37°C. For irrigating solutions, each prepared sample was immersed in 1 ml of sterile saline for 1 min, followed by irrigating and immersion with 1.5% NaOCl and 2% CHX for 5 min. An antimicrobial assessment was performed at the end of 2 days and 7 days, with seven teeth from each group, for each time interval. Dentin debris collected was transferred to the respective medium for culture. After 24 h, colonies were counted using classical bacterial counting technique as colony-forming units.

Results

Statistical analysis revealed that the novel antibiotic-steroid paste showed a statistically insignificant difference when compared to DAP, which had the highest antimicrobial properties.

Conclusion

This novel functional paste has antimicrobial efficacy comparable with that of DAP.

Antibacterial Activity of Sodium Hypochlorite Gel versus Different Types of Root Canal Medicaments Using Agar Diffusion Test: An In Vitro Comparative Study

Aim

This study aimed to evaluate the antibacterial effect of sodium hypochlorite gel and four types of intracanal medicaments.

Materials and Methods

The agar diffusion method was used to evaluate the antibacterial effect of five medicaments (sodium hypochlorite gel (NaOCl), chlorhexidine gel (CHX), calcium hydroxide paste (CH), Ledermix, and Diapex plus) against Enterococcus faecalis (E. faecalis), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The zone of inhibition around each medicament was measured in millimeters, after 48 hours of incubation at 37°C. The antibacterial effects of medicaments against each microbial strain and the sensitivity of microorganisms towards each medicament were compared using the one-way ANOVA and Games–Howell post hoc tests. The level of significance was set to p < 0.05.

Results

All medicaments showed variable inhibition zones for all bacterial strains except Diapex Plus which showed no antibacterial activity. NaOCl gel exhibited the most significant inhibition zones for all bacterial strains followed by CHX gel, Ledermix, and CH. However, the effect of CHX and CH paste against S. aureus was statistically similar, while the effect of CH against E. faecalis was significantly higher than the Ledermix.

Conclusion

Sodium hypochlorite gel displayed the highest antibacterial activity among tested medicaments and can be recommended as a potent intracanal medicament. Chlorhexidine gel showed a significantly higher antibacterial effect when compared with Ledermix and calcium hydroxide. Calcium hydroxide demonstrated stronger antibacterial activity against E. faecalis than Ledermix. Diapex Plus exhibited no antibacterial effect.

The Efficiency of the Er: YAG Laser and PhotonInduced Photoacoustic Streaming (PIPS) as an Activation Method in Endodontic Irrigation: A Literature Review

In the field of endodontics, lasers have been used for a long time for the optimization of Endodontic irrigation in particular. The laser-activated irrigation (LAI) technique is based on the photomechanical effects of the lasers at low settings. They create specific cavitation phenomena and acoustic streaming in intracanal fluids. More recently, a new technique with a Er:YAG laser has been used with sub-ablative energy (20 mJ, 15 Hz) and ultra-short pulses (50 µs). This leads to intracanal cavitation and shockwaves as a result of photoacoustic and photomechanical effects. This phenomenon is called photon-induced photoacoustic streaming (PIPS). PIPS and Laser activated irrigation are described in the literature as a revolutionary and powerful method to activate the irrigant; however, systematic literature on this topic is missing. This review compares the literature on Er:YAG LAI and PIPS on endodontic irrigation with other irrigation methods. An article search was performed on the PubMed database using a series of keywords related to endodontic irrigation, including Er:YAG LAI and PIPS; 59 articles were selected for the review according to the inclusion and exclusion criteria. No in vivo study was found. The Er:YAG LAI and PIPS outperformed other methods in 33 of the 59 articles. There was a great variety in the study designs including bacterial incubation time, laser parameters, irrigation protocols, and irrigating solution used. The evidence suggests that the Er:YAG LAI and PIPS are promising in canal disinfection as well as debris and smear layer removal. However, the large variety in the study methods makes the results less significant. Further studies are needed to better evaluate the efficiency of these techniques, especially in vivo studies.

Effect of Intracanal Medicaments on Pull-Out Bond Strength of Fiber Post Cemented with a Self-Adhesive System

OBJECTIVES

 This study aimed to assess the effect of four intracanal medicaments on pull-out bond strength of fiber posts.

MATERIALS AND METHODS

 A total of 65 single-rooted, single-canal teeth were selected and decoronated. Root canals were prepared and after rinsing were randomly divided into five groups (n = 13). G₁: calcium hydroxide (CH), G_2: CH plus chlorhexidine (CH+CHX), G₃: triple antibiotic paste (TAP), G₄: double antibiotic paste (DAP) were applied in the canals in the four groups. The control group (G₅) received no medicament. After 4 weeks, the medicaments were rinsed off and the canals were filled with gutta-percha. Post space was then prepared in root canals for the placement of glass fiber posts and self-adhesive cement (Panavia F2). After cementation, they were subjected to pull-out bond strength test.

STATISTICAL ANALYSIS

 Data were statistically analyzed using one-way analysis of variance and Tukey test.Results The pull-out bond strength values were significantly different in the groups (p < 0.001). The highest values of bond strength were seen in G₂, G₁, and G₃ (359.97 ± 81.26, 333.79 ± 98.96, 309.27 ± 78.07), respectively. There was no significant difference between G₄ and G₅ (p = 0.75).

CONCLUSION

 The results showed that CH, CH+CHX, and TAP enhanced the pull-out bond strength of fiber post to root canal wall as compared to the control group.

Comparison of intracoronal bleaching methods on teeth discolored by different antibiotic pastes

AIM

To compare the bleaching efficacy of sodium perborate with different activation methods on crowns discolored by two different antibiotic pastes.

MATERIALS AND METHODS

Eighty-five extracted human incisors were prepared to size #30 using ProTaper rotary instruments. After chemomechanical preparation and irrigation procedures, the specimens received triple antibiotic paste (TAP, n = 40), minocycline paste (MP, n = 40), or calcium hydroxide (n = 5, control group) and coronally sealed with temporary filling material. Spectrophotometric readings were obtained on day 0-week 4. Data were analyzed with the Mann-Whitney U-test and Wilcoxon sign test (P < 0.05). Sodium perborate was then inserted into the pulp chambers of discolored teeth (four subgroups, n = 10) and activated by heat or ultrasonically using two different frequencies and times. Spectrophotometric readings were obtained on days 3-7. Data were analyzed by the Mann-Whitney U-test and Kruskal-Wallis test (P > 0.05).

RESULTS

Both groups showed statistically significant coronal discoloration at each time interval (P < 0.01), but their final shades did not significantly differ between the groups (P > 0.05). Although the MP subgroups exhibited more bleaching than the TAP subgroups on days 3 and 7, the difference was not significant (P > 0.05). The bleaching results for the sodium perborate activation techniques did not significantly differ among groups (P > 0.05).

CONCLUSIONS

Both antibiotic pastes induced crown discoloration that was reversible using all sodium perborate bleaching techniques.

Is it really penetration? Part 2. Locomotion of Enterococcus faecalis cells within dentinal tubules of bovine teeth

OBJECTIVE

The aim of the present vitro study was to examine the question whether devitalized Enterococcus faecalis (E. faecalis) cells can migrate into dentinal tubules and if that process takes place in a time-dependent manner.

DESIGN

Sixty bovine root canals were incubated with devitalized and vital streptomycin-resistant E. faecalis strains after root canal enlargement (size 80, taper .02) with 3% NaOCl solution. Incubation times 7, 14, 21, 28, 35, and 42 days. Samples were processed for analysis by scanning electron microscopy (SEM) and DAPI (4',6-diamidino-2-phenylindole) staining. The penetration depth was calculated with the measurement tool of the Axio Vision program (Zeiss, Jena, Germany). Statistical analysis was performed by Kruskal-Wallis (α = 0.05) and Mann-Whitney U test (p < 0.05).

RESULTS

Devitalized E. faecalis strains were able to migrate into dentinal tubules. The total number and penetration depth of devitalized E. faecalis cells was lower compared to the vital suspension of E. faecalis. It was noted, that bacterial penetration was not common to all of the dentinal tubules in the vital E. faecalis control and especially in the devitalized control. The migration took place in a time-dependent migration characteristic.

CONCLUSIONS

Devitalized E. faecalis cells are still able to migrate into the dentinal tubules due to possible electrokinetic and osmotic processes. Thereby, increased exposure times lead to a time-dependent penetration characteristic.

CLINICAL RELEVANCE

Since devitalized bacteria can migrate as well into dentinal tubules, the presence of bacteria within dentinal tubules cannot be interpreted as a failure of tested preparation regimens.

A survey of the knowledge, attitude, and awareness about the principal choice of intracanal medicaments among the general dental practitioners and nonendodontic specialists

BACKGROUND

Removal of the microbial organisms from the root canal system is a prerequisite for the successful outcome of any root canal treatment. Use of an effective intracanal medicament will assist in the disinfection of the root canal system. Intracanal medicaments have been used to disinfect root canals between appointments and reduce interappointment pain.

MATERIALS AND METHODS

A questionnaire survey was conducted to evaluate the knowledge, attitude, and awareness about the principal choice of intracanal medicaments among general dental practitioners and nonendodontic specialists. The questionnaire consisted of 11 questions related to intracanal medicaments in Endodontics. It was distributed to 75 general dental practitioners and 75 other specialists (nonendodontists).

RESULTS

In the present study, the authors observed that the knowledge level among the study participants was moderately satisfying. However, the need for more education of the dentists with regard to the intracanal medicaments was perceived.

DISCUSSION

Correct knowledge of intracanal medicaments would help the practitioners to decide the apt material of choice as intracanal medicaments in different clinical situations.

CONCLUSION

The present study highlighted the need for more continuing dental education programs with active participation of general practitioners and nonendodontic specialists to update themselves.

Hydroxyl Ion Diffusion through Radicular Dentine When Calcium Hydroxide Is Used under Different Conditions

Calcium hydroxide’s anti-bacterial action relies on high pH. The aim here was to investigate hydroxyl ion diffusion through dentine under different conditions. Teeth were divided into control (n = 4) and four experimental groups (n = 10): Group 1—no medicament; Group 2—Calmix; Group 3—Calmix/Ledermix; Group 4—Calasept Plus/Ledermix; Group 5—Pulpdent/smear layer. Deep (inner dentine) and shallow (outer dentine) cavities were cut into each root. pH was measured in these cavities for 12 weeks. The inner and outer dentine pH in Group 2 was significantly higher than all groups. Inner dentine pH in Group 3 was slightly higher than that in Group 4 initially but subsequently comparable. After Day 2, Group 5 had significantly lower pH than Groups 3 and 4. The outer dentine pH in Group 3 started higher than that in Groups 4 and 5, but by Day 28 the difference was insignificant. The time for the inner dentine to reach maximum pH was one week for Group 2 and four weeks for Groups 3 and 4. The time for the outer dentine to reach maximum pH was eight weeks for all experimental groups. Mixing different Ca(OH)₂ formulations with Ledermix gave similar hydroxyl ion release but pH and total diffusion was lower than Ca(OH)₂ alone. The smear layer inhibited diffusion.

Comparative scanning electron microscopy evaluation of Canal Brushing technique, sonic activation, and master apical file for the removal of triple antibiotic paste from root canal (in vitro study)

Aims:

To compare and evaluate the effectiveness of Canal Brushing technique, sonic activation, and master apical file (MAF) for the removal of triple antibiotic paste (TAP) from root canal using scanning electron microscopy (SEM).

Materials and Methods:

Twenty-two single rooted teeth were instrumented with ProTaper up to the size number F2 and dressed with TAP. TAP was removed with Canal Brush technique (Group I, n: 6), sonic (EndoActivator) (Group II, n: 6), and MAF (Group III, n: 6). Four teeth served as positive (n: 2) and negative (n: 2) controls. The roots were split in the buccolingual direction and prepared for SEM examination (×1000) at coronal, middle, and apical third. Three examiners evaluated the wall cleanliness.

Statistical Analysis:

Statistical analysis was performed by Kruskal–Wallis test and Wilcoxon rank sum test.

Results:

Difference in cleanliness between three groups is statistically significant in cervical region only. Pairwise comparison in cervical region Canal Brush and sonic activation showed more removal of TAP than MAF.

Conclusions:

Canal Brush and sonic activation system showed better result than MAF in the cervical and middle third of canal. In the apical third, none of the techniques showed a better result. None of the techniques showed complete removal of TAP from the canal.

Intracanal Antibiotic Medication for Sustained Root Surface Disinfection-A Laboratory Evaluation

Purpose:

To measure the release of an antibiotic mixture of ciprofloxacin, cerfuroxim and metronidazole (TreVitaMix, TVM) through human dentine and to assess the growth inhibition of Fusobacterium nucleatum.

Material and Methods:

Twenty-four extracted human incisors were scaled and endodontically treated. Root canals were either filled with antibiotic tri-mixture (TVM) or with the carrier material alone (propylene glycol, PG) and were coronally and apically sealed with a flowable composite. Transradicular medicament release was spectrophotometrically measured at 277 nm in simulated body fluid for up to 21 days. In a second part, an agar diffusion assay (F. nucleatum) with representative TVM concentrations as determined in the first part was performed to study the growth inhibition. Samples were anaerobical incubated for 48 h and inhibition zones were measured.

Results:

TVM was spectrophotometrically detectable in the immersion solution and released in decreasing concentrations up to 21 days (222.5 ± 65.2 mg/ml at day 1 and 35.1 ± 15.6 mg/ml at day 21). In addition, inhibition zones were shown in the agar diffusion assay at representative TVM concentrations. The carrier material showed no antibacterial effect.

Conlusion:

TVM showed the potential to penetrate through dentine and to inhibit bacterial growth. Therefore, it might have the potential to disinfect the outer root surface in perio-endo lesions, but further research is needed to confirm these observations.

Retrievabilty of calcium hydroxide intracanal medicament with Chitosan from root canals: An in vitro CBCT volumetric analysis

AIM

This study compared the amount of aqueous-based and oil-based calcium hydroxide [Ca(OH)2 ] remaining in the canal, after removal with two different chelators 17% EDTA and 0.2% Chitosan in combination with ultrasonic agitation.

MATERIALS AND METHODS

Cleaning and shaping of root canals of 28 mandibular premolar was done and canals were filled either with Metapex or Ca(OH)2 mixed with distilled water. Volumetric analysis was performed utilizing cone beam-computed tomography (CBCT) after 7 days of incubation. Ca(OH)2 was removed using either 17% EDTA or 0.2% Chitosan in combination with ultrasonic agitation. Volumetric analysis was repeated and percentage difference was calculated and statistically analysed using Kruskal-Wallis and Mann-Whitney U test.

RESULTS

Both the chelators failed to remove aqueous-based as well as oil-based Ca(OH)2 completely from the root canal. Aqueous-based Ca(OH)2 was easier to be removed than oil-based Ca(OH)2. 0.2% Chitosan was significantly more effective for removal of oil-based Ca(OH)2 (P < 0.01) while both 17% EDTA and 0.2% Chitosan were equally effective in removing aqueous-based Ca(OH)2 .

CONCLUSION

Combination of 0.2% Chitosan and ultrasonic agitation results in lower amount of Ca(OH)2 remnants than 17% EDTA irrespective of type of vehicle present in the mix.

Overview on the current antibiotic containing agents used in endodontics

Antibiotics are systemically and locally used extensively in endodontics. However, local antibiotic application mode is considered more effective than systemic administration. The local mode enables the dentist to target bacteria in every nook and corner of root canal system, which is otherwise beyond reach if targeted by instrumentation or conventional root canal treatment protocols. Therefore, they are an important adjunct to conventional treatment of root canal. The present study reviews the various antibiotic containing dental agents used in endodontics. A web-based research on MedLine was performed with terms Review Articles published in the last 10 year's dental journals in English for literature researching, extracting, and synthesizing data. Relevant articles were shortlisted. Important cross-reference articles were also reviewed.

Discoloration of roots caused by residual endodontic intracanal medicaments

AIMS

This study examined the extent to which intervisit corticosteroid-based antibiotic pastes (CAP) medicaments contribute to staining of tooth structure after attempted removal by irrigation techniques.

METHODS

A total of 140 roots were prepared and the canals were filled with Ledermix paste (demeclocycline), Odontopaste (clindamycin), and Doxypaste (doxycycline). The pastes were removed after 2 or 4 weeks of storage in the dark using EDTA and NaOCl with either a 27-gauge-slotted needle or an EndoActivator (Dentsply). The roots were then exposed to an intense light source for 30 minutes each week and photographed after a further 1, 3, or 6 months. Digital images were standardized and data for changes in luminosity were analysed using repeated measures ANOVA and a post hoc test.

RESULTS

Removal of the medicament did not prevent later discolouration. There was no significant difference between the paste removal methods. Ledermix paste caused the greatest darkening compared to the untreated controls, for both application periods and both methods of removal. Doxypaste and Odontopaste caused less darkening than Ledermix.

CONCLUSION

Medicaments that stain teeth may continue to discolour teeth despite best attempts to remove them. This study stresses the importance of material selection and minimising contact of Ledermix within the coronal aspects of teeth.

Analgesic effect of odontopaste and a compound intracanal medicament between root canal therapy appointments

BACKGROUND

Pain experience makes a serious anxiety for both patient and clinician before and after root canal treatment. Pain is a complex psychophysiologic phenomenon.

OBJECTIVES

The aim of this randomized control trial study was to evaluate the analgesic effect of Odontopaste® and a corticosteroid containing compound medicament between root canal therapy appointments.

MATERIALS AND METHODS

One hundred and twenty lower first and second mandibular molars with spontaneous pain and sensitivity to percussion were selected and divided into three groups (40 patients per each group). After root canal preparation, patients were entered one of these groups randomly. Root canals in group 1 were dressed with Odontopaste, in group 2 with a compound intracanal medicament, and in group 3 with placebo. Patients determined their pain rate and percussion sensitivity on Heft-parker VAS diagram, before the first appointment and 24 hours and 7 days after that.

RESULTS

Spontaneous pain and Percussion sensitivity score averages of 24 hours after the first appointment in group 1 and group 2 were less than group 3, which indicates statistically significant difference between these groups. There was no statistically significant difference between these groups after 7 days neither on spontaneous pain nor percussion sensitivity.

CONCLUSIONS

Odontopaste® and compound intracanal medicaments resulted in statistically significant reduction in postoperative pain and percussion sensitivity after 24 hours, but there was no statistically significant difference after 7 days with placebo.

Antibacterial activity of calcium hydroxide combined with chitosan solutions and the outcomes on the bond strength of RealSeal sealer to radicular dentin

The purpose of this study was to investigate the antibacterial activity of calcium hydroxide [Ca(OH)₂] combined with chitosan solutions against Enterococcus faecalis-infected root canal dentin and the effect of this new intracanal medicament on the bond strength of RealSeal sealer to radicular dentin. An experimental intracanal medicament was prepared by mixing different concentrations of chitosan solution (25%, 50%, and 100%, W/V) to Ca(OH)₂ powder. Antibacterial activity was evaluated and the total numbers of colony forming units were determined. Bonding ability of RealSeal sealer to radicular dentin was evaluated using push-out bond strength test. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's multiple comparison tests. We found that Ca(OH)₂ combined with different concentrations of chitosan solutions showed better antibacterial activity than Ca(OH)₂ mixed with saline, without significantly affecting the bond strength of RealSeal sealer to radicular dentin (P > 0.05). The findings suggest that Ca(OH)₂ combined with chitosan is a promising intracanal medicament and may be effective in endodontic therapy.

Teeth with double internal inflammatory resorption: report of two cases

Internal inflammatory resorption is an uncommon condition, which requires the presence of necrotic and infected pulp tissue within the coronal portion of the root canal system as well as inflamed pulp tissue apical to the resorptive defect. The defect usually appears as a bowl-shaped radiolucency within the tooth root. Most cases are asymptomatic and many cases are only seen once the entire pulp has necrosed and all of the root canal system is infected resulting in apical periodontitis. The two cases presented are unusual in that they both had two distinct areas of internal inflammatory resorption. It is hypothesised that the more coronal lesion occurred first and then it ceased to continue resorbing the root in that position as the 'necrotic, infected front' moved apically at which time a second resorptive defect developed. The management, using different approaches, of these two cases of 'double internal inflammatory resorption' is described.

Strategies for the endodontic management of concurrent endodontic and periodontal diseases

Endodontic and periodontal diseases can provide many diagnostic and management challenges to clinicians, particularly when they occur concurrently. As with all diseases, a thorough history combined with comprehensive clinical and radiographic examinations are all required so an accurate diagnosis can be made. This is essential since the diagnosis will determine the type and sequence of treatment required. This paper reviews the relevant literature and proposes a new classification for concurrent endodontic and periodontal diseases. This classification is a simple one that will help clinicians to formulate management plans for when these diseases occur concurrently. The key aspects are to determine whether both types of diseases are present, rather than just having manifestations of one disease in the alternate tissue. Once it is established that both diseases are present and that they are as a result of infections of each tissue, then the clinician must determine whether the two diseases communicate via the periodontal pocket so that appropriate management can be provided using the guidelines outlined. In general, if the root canal system is infected, endodontic treatment should be commenced prior to any periodontal therapy in order to remove the intracanal infection before any cementum is removed. This avoids several complications and provides a more favourable environment for periodontal repair. The endodontic treatment can be completed before periodontal treatment is provided when there is no communication between the disease processes. However, when there is communication between the two disease processes, then the root canals should be medicated until the periodontal treatment has been completed and the overall prognosis of the tooth has been reassessed as being favourable. The use of non-toxic intracanal therapeutic medicaments is essential to destroy bacteria and to help encourage tissue repair.

The use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodontics

Bacteria have been implicated in the pathogenesis and progression of pulp and periapical diseases. The primary aim of endodontic treatment is to remove as many bacteria as possible from the root canal system and then to create an environment in which any remaining organisms cannot survive. This can only be achieved through the use of a combination of aseptic treatment techniques, chemomechanical preparation of the root canal, antimicrobial irrigating solutions and intracanal medicaments. The choice of which intracanal medicament to use is dependent on having an accurate diagnosis of the condition being treated, as well as a thorough knowledge of the type of organisms likely to be involved and their mechanisms of growth and survival. Since the disease is likely to have been caused by the presence of bacteria within the root canal, the use of an antimicrobial agent is essential. Many medicaments have been used in an attempt to achieve the above aims but no single preparation has been found to be completely predictable or effective. Commonly used medicaments include calcium hydroxide, antibiotics, non-phenolic biocides, phenolic biocides and iodine compounds. Each has advantages and disadvantages, and further research is required to determine which is best suited for root canal infections.

Conservative endodontic management of teeth associated with extensive periapical pathology: report of two cases

Traditionally, long-term calcium hydroxide dressings have been recommended for the conservative management of large periapical lesions. However, calcium hydroxide therapy has some disadvantages such as variability of treatment time, difficulties with patient follow-up and prolonged treatment periods that increase the risk of root canal contamination via microleakage and crown fractures. This paper reports the healing of large periapical lesions following conservative non-surgical treatment with calcium hydroxide dressings.

Role Of Occlusion In Endodontic Management: Report Of Two Cases

The two clinical cases reported demonstrate that traumatic occlusion can play a role in the initiation and progression of pulp and periradicular inflammation. The symptom of persistent pain did not subside after the commencement of endodontic treatment. Traumatic occlusion was identified in both cases to be the main cause and hence occlusal adjustment was performed. This resulted in the gradual resolution of the symptoms. The findings suggest that occlusal trauma is often overlooked in the diagnosis and management of endodontic diseases.

Postoperative pain after endodontic retreatment: Single- versus two-visit treatment

OBJECTIVE

The purpose of this clinical study was to determine the effect of 1- or 2-visit root canal treatment on the postoperative pain in the retreatment cases.

STUDY DESIGN

Two hundred eighteen cases that required retreatment were included in the study. Obturated and unfilled canal space and the status of periapical tissues were evaluated according to the PAI index. The patients were subcategorized in regard to the presence or the absence of preoperative pain. Approximately half of each category was treated in 1 appointment. After removing the previous root canal obturation materials and biomechanic preparation of root canals, the teeth in the 1-visit group were obturated at the first appointment by using AH 26 sealer and laterally compacted gutta-percha, and those in the 2-visit group were medicated with calcium hydroxide-chlorhexidine combination and then closed with a temporary filling material. One week after the initial appointment, patients were asked about the occurrence of postoperative pain. The level of discomfort was rated as no pain, mild pain, moderate pain, or severe pain (flare-up). Data were statistically analyzed using the chi-squared and Fischer exact tests.

RESULTS

Eight patients from the 1-visit group and 2 patients from the 2-visit group had flare-ups. There was a statistical difference between the groups (P <.05). Two-visit root canal treatment was more effective in completely eliminating pain than 1-visit treatment of previously symptomatic teeth (P <.05).

CONCLUSIONS

Two-visit endodontic treatment with intracanal medication was found to be effective in reducing postoperative pain of previously symptomatic teeth and decreased the number of flare-ups in all retreatment cases.

Calcium hydroxide as an intracanal medication: effect on posttreatment pain

Calcium hydroxide is advocated as an intracanal medication for various purposes, 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 random, 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.

Dental science--reality of the evidence

Primary Dental Care publishes below the text of the Professor William Britto-Muthunayagam oration, which was delivered by the author earlier this year in Sri Lanka.

Penetration of bacteria in bovine root dentine in vitro

AIM

The aim of this study was to develop a test model to quantify the penetration of bacteria into dentinal tubules.

METHODOLOGY

The model consisted of two compartments separated by a bovine dentine specimen with a thickness of 1.5-3.1 mm. The root cementum was removed from the root surface and the specimens were oriented in the model with the pulpal side facing the inoculated chamber of the test model. One compartment contained the test organism and the other was filled with sterile broth that was evaluated for growth of the test organism. The depth of bacterial penetration was measured in the dentine with or without a smear layer using both a histological and a quantitative recovering grinding technique, after 6 weeks of exposure to the microorganisms.

RESULTS

E. faecalis penetrated dentine significantly deeper than A. israelii (P < 0.001). After removal of the smear layer with EDTA, E. faecalis penetrated significantly deeper than in dentine pretreated with saline only (P < 0.01) or with a combination of saline and sodium hypochlorite (P < 0.01). Microorganisms were found in 89% of the cultured specimens and in 80% of the specimens that were evaluated with light microscopy. Total penetration through the dentine specimen and infection of the broth in the test compartment of the model occurred in only two out of 72 specimens.

CONCLUSION

Collection and immediate culturing of infected dentine dust and counting colony forming units (CFU) allowed an overview of the number of bacteria per sample and was more sensitive than microscopy. Removal of the smear layer enhanced bacterial penetration.

Recontamination of coronally unsealed root canals medicated with camphorated paramonochlorophenol or calcium hydroxide pastes after saliva challenge

This in vitro study evaluated the ability of some medications to prevent recontamination of coronally unsealed root canals by bacteria from saliva. The medications tested were camphorated paramonochlorophenol (CPMC) applied in cotton pellets in the pulp chamber; calcium hydroxide/saline solution paste filling the root canal; and calcium hydroxide/CPMC/glycerin paste also filling the root canal. Medicated canals were exposed to saliva, and the number of days required for total recontamination to occur was recorded. Canals medicated with CPMC in cotton pellets were thoroughly recontaminated within an average of 6.9 days. Canals filled with calcium hydroxide/saline solution and calcium hydroxide/CPMC/glycerin showed entire recontamination within an average of 14.7 and 16.5 days, respectively. Calcium hydroxide pastes were significantly more effective than CPMC (p < 0.05).

Lower lip paraesthesia following restoration of a second premolar tooth. Case report

A forty year old female patient developed paraesthesia of the right side of her lower lip following the placement of an extensive pin-retained amalgam restoration in her lower right second premolar tooth. Radiographs indicated that the mental foramen was close to the apex of this tooth and it was assumed that postoperative pulpitis and periapical inflammation had caused the paraesthesia through the effects of pressure on the mental nerve. The paraesthesia resolved following endodontic treatment of the lower second premolar tooth and the patient has had no further signs or symptoms.

Is antibiotic prophylaxis required for endodontic treatment?

The stable prevalence of infective endocarditis since the advent of antibiotic prophylaxis for patients at-risk reflects the increasing polymicrobial etiology of such infections not associated with dental procedures. In addition to concerns for the growing crisis for antibiotic-resistant bacteria, the need for controlled clinical trials to determine the continued efficacy of prophylactic regimens for endodontic and other dental procedures cannot be overstated.

Factors associated with continuing pain in endodontics

A survey of 100 patients referred to a specialist endodontic practice was undertaken to determine the frequency of various factors associated with continuing pain after endodontic treatment had been commenced by the patient's general dental practitioner. Information was obtained by questioning the patient, examining the tooth, reviewing information supplied by the referring dentist and by observation during subsequent treatment. There were 23 different factors associated with continuing pain--all patients had more than one factor; most (78 per cent) had four, five or six factors; the highest was 9 factors (2 per cent). The most commonly occurring factors were: lack of use of rubber dam (87 per cent), unsatisfactory temporary restorations (80 per cent), and inappropriate use of intracanal medicaments (71 per cent). The other factors were related to diagnostic or treatment errors that could have been avoided in most cases. This survey suggests that dentists need to pay more attention to basic treatment recommendations in order to predictably relieve pain when carrying out emergency endodontics.

Low surface tension calcium hydroxide solution is an effective antiseptic

The antimicrobial effects of a saturated calcium hydroxide solution, and in combination with 10% and 20% detergent, were evaluated on Streptococcus faecalis, Streptococcus sanguis, Streptococcus mutans, Streptococcus salivarius, Neisseria sp., diphtheroid, Staphylococcus aureus, Lactobacillus sp., Staphylococcus epidermidis, Bacillus subtilis and Candida albicans. The saturated calcium hydroxide solution was effective against only four of the 11 microorganisms studied over a 60-min exposure time. The calcium hydroxide solutions containing detergent killed all 11 test organisms over a 30-min exposure time. This difference was statistically significant (P < 0.01). No statistically significant difference in antimicrobial action was found between the 10% and 20% detergent calcium hydroxide solutions (P > 0.01). However, the low surface tension (46.5 x 10(-3) Nm-1) and high pH (10.8) of the calcium hydroxide solution with 20% detergent establish it as the more effective solution.

An SEM study of the effects of different irrigation sequences and ultrasonics

The root canals of 30 extracted human teeth with single canals were prepared biomechanically with hand instruments using a flaring technique. Three different irrigation regimes were used, with and without ultrasonic activation of a root canal file. The six irrigation sequences used in this study were as follows: Savlon, Savlon with ultrasound, EDTAC/NaOCl/EDTAC, EDTAC/NaOCl/EDTAC with ultrasound, NaOCl/EDTAC/NaOCl, and NaOCl/EDTAC/NaOCl with ultrasound. Scanning electron microscopic (SEM) examination of the prepared root canal walls showed a complete smear layer when Savlon was used. Ultrasound reduced the amount of smear with Savlon, but did not do so significantly with the other irrigation regimes. The most effective irrigation regime for removing smear layer and other debris was EDTAC/NaOCl/EDTAC. In all groups there was a significant decrease in cleaning efficiency as the apical end of the canal was approached.

Medicaments: aids to success in endodontics. Part 2. Clinical recommendations

In order to predictably achieve bacteria-free root canal systems, especially in pulpless teeth, it is necessary to use intra-canal medicaments. Medicaments can also be used to influence the peri-radicular response to endodontic treatment. Consideration of a material's therapeutic action must be made when selecting a medicament for any pathological condition. In general, only two commercial preparations satisfy the general requirements for root canal medicaments. Guidelines and the rationale for the use of these preparations are presented.