Efficacy of various techniques in calcium silicate-based intracanal medicament removal: a micro-CT analysis

The purpose of this study was to evaluate the efficacy of different techniques in removing calcium silicate intracanal medicament (Bio-C Temp). Forty human single-canaled premolars were randomly distributed into five groups (n = 8). All root canals were instrumented, then filled with Bio-C Temp. Following 1-week incubation, the intra-canal medicament was removed using one of five techniques according to tooth group: conventional syringe irrigation, Endo Activator, passive ultrasonic irrigation (PUI), ProTaper Universal F3 and XP-endo Finisher (XPF). Micro-CT scanning was performed before and after removal of Bio-C Temp. All techniques significantly reduced the volume of Bio-C Temp (p < 0.001) without reaching complete elimination. The percentage of Bio-C Temp removed was significantly higher in the XPF group (98.2%) compared to conventional syringe irrigation (70.6%), the Endo Activator (75.7%), and the ProTaper Universal (76.6%). There was no significant difference between the XPF and PUI (95.1%) groups. None of the removal techniques were able to completely remove Bio-C Temp from the root canal. However, XPF was the most effective method, but was not statistically significant when compared to PUI. Clinical Relevance: This study demonstrated that both XPF and PUI outperform conventional irrigation in removing Bio-C Temp intracanal medicament.

Effect of Curcuma longa (Turmeric), as an intra-canal medicament, on inter-appointment endodontic pain in patients with symptomatic irreversible pulpitis: A randomized controlled clinical trial

Inter-appointment pain (IAP) is a subtype of postoperative pain which occurs between endodontic appointments. It may begin within a few hours after the first appointment and may continue for several days. Apart from mechanical instrumentation and thorough irrigation, intracanal medicaments play a central role in the disinfection of root canals and thus decreasing IAP. The aim of this study was to evaluate the effect of Curcuma Longa as an intracanal medicament on IAP in patients with symptomatic irreversible pulpitis (SIP). One hundred healthy adult patients having SIP in one of their single-rooted maxillary or mandibular teeth participated in this randomized, parallel, single-blinded clinical trial. After thorough biomechanical preparation, the root canals were randomly medicated with one of the following medicaments, Control (no medicament), Calcium Hydroxide, triple antibiotic paste (TAP), and Curcuma Longa. The pain was recorded using Visual analog scale at 4 h, 24 h, and every day until the seventh day. Data were analyzed using Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed-rank tests. No statistical difference in pain scores was observed between Calcium Hydroxide, TAP or Curcuma Longa groups. It can be concluded that Curcuma Longa, Calcium hydroxide, and TAP are equally effective in controlling IAP.

Novel strategies enhancing endodontic disinfection: Antibacterial biodegradable calcium hydroxide nanoparticles in an ex vivo model

Due to the high failure rates associated to endodontic disinfection, this study aimed to investigate the antibacterial properties of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with Ca(OH)2 for endodontic disinfection procedures. Ca(OH)2 NPs production and physicochemical characterization were carried out as well as multiple antibacterial tests using three bacterial strains and an ex vivo model of endodontic infection with extracted human teeth. Agar diffusion test and broth dilution determined the inhibition growth zones (n = 5) and the minimal inhibitory concentration (MIC, n = 5), respectively. Cell viability was assessed using Live/Dead staining with confocal microscopy (n = 5). Data was analysed using ANOVA followed by post-hoc analysis. After 24 h of incubation, Ca(OH)₂ NPs demonstrated a MIC of 10 µg/mL for Porphyromonas gingivalis (p < 0.001) and Enterococcus faecalis and 5 µg/mL for Fusobacterium nucleatum (p < 0.001). Although the agar diffusion test did not exhibit any inhibition area for Ca(OH)2 nor for Ca(OH)₂ NPs, this was probably due to the buffering effect of the agar medium. However, the antibacterial capacity was confirmed in an ex vivo model, where instrumentalized teeth were infected with Enterococcus Faecalis and treated after 28 days of culture. A significant reduction in bacterial metabolic activity was confirmed for Ca(OH)2 NPs (40 % reduction with a single dose) and confirmed by Live/Dead staining. In conclusion, Ca(OH)₂-loaded PLGA NPs present promising antibacterial efficacy for endodontic disinfection procedures.

Outcome of Endodontic Treatment through Existing Full Coverage Restorations: An Endodontic Practice Case Series

INTRODUCTION

This case series assessed the outcome of nonsurgical endodontic treatment completed through retained full coverage restorations (FCRs) in a board-certified endodontist private practice. The number of cases completed by the first author was 153.

METHODS

All cases were performed following a standardized protocol for treatment and restoration depending on the type of FCR. Number of cases that showed up for 2- to 4-year follow-up was 127, with 83% recall rate. The age range of patients was 33-95 years, with mean age of 54.734 years. The mean recall time was 2.448 years. FCRs and their distribution were as follows: 4 anterior teeth, 14 premolars, and 109 molars. There were 103 nonsurgical root canal treatments and 24 retreatments. Patients who presented for recall had 74 porcelain fused to metal crowns, 17 zirconia crowns, 15 abutments of porcelain fused to metal bridges, 14 lithium disilicate crowns, 5 gold crowns, 1 full metal crown, and 1 gold onlay.

RESULTS

There were no endodontically related failures. Six cases failed; 3 were due to vertical root fractures, 1 was due to horizontal root fracture, and 2 were due to extensive recurrent caries causing restorative failure. The percentage of healed cases following the American Association of Endodontists outcome criteria adopted in 2004 with intact retained FCR was 95.3%.

CONCLUSIONS

The results suggest predictable favorable outcomes for nonsurgical endodontic treatment through FCR following the proposed protocol for diagnosis, treatment, and restoration.

Incidence and Severity of Postoperative Pain Following Root Canal Treatment in Nonvital Pulps with Hand and Rotary Instrumentation Techniques in Chhattisgarh Population

Aim:

To evaluate the incidence and severity of postoperative pain following root canal treatment in nonvital pulps with hand and rotary instrumentation techniques in Chhattisgarh population.

Materials and Methods:

Sixty asymptomatic single-canaled nonvital teeth were selected and were divided into two groups of 30 each. Group I: 30 single-canalled teeth were treated in a single visit and prepared with hand file system. Group II: 30 single-canaled teeth treated in a single visit and prepared with K3-rotary file system. Group I and II were divided into two subgroups of 15 each (Group IA, IB and Group IIA, IIB) which were irrigated with 2% chlorhexidine and 5.25% sodium hypochlorite, respectively. The patients were recalled at 24, 48, and 72 h and at 1 week to record the incidence and severity of postoperative pain by using visual analog scale.

Results:

Results showed low incidence and severity of postoperative pain following a single-visit treatment with rotary instrumentation when compared to hand instrumentation technique. No statistical significant difference was observed between the groups at different time intervals, i.e., at 24, 48, and 72 h and at 1 week. The use of recent endodontic techniques and devices reduces the postoperative pain.

Conclusions:

Postoperative pain after root canal treatment ranged from mild to severe and it can happen even after high-standard root canal treatment. There is low incidence and severity of postoperative pain following a single-visit treatment with rotary instrumentation when compared to hand instrumentation technique.

Calcium hydroxide-loaded PLGA biodegradable nanoparticles as an intracanal medicament

AIM

To develop a formulation in which calcium hydroxide (Ca(OH)₂) was successfully loaded into poly(lactic-co-glycolic acid) (PLGA) biodegradable nanoparticles (NPs) to be used in the field of endodontics as an intracanal medicament, including NP optimization and characterization, plus drug release profile of the NPs compared with free Ca(OH)₂. Additionally, the depth and area of penetration of the NPs inside the dentinal tubules of extracted teeth were compared with those of the free Ca(OH)₂.

METHODOLOGY

Ca(OH)₂ NPs were prepared using the solvent displacement method. NPs was optimized with a central composite design to obtain a final optimized formulation. The morphology of the NPs was examined under transmission electron microscopy (TEM), and characterization was carried out using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). The drug release profile of the Ca(OH)₂ NPs and free Ca(OH)₂ was evaluated up to 48 h. Finally, the depth and area of penetration inside the dentinal tubules of extracted teeth were examined for both the Ca(OH)₂ NPs and free Ca(OH)₂ using the Mann-Whitney U test to determine any significant differences.

RESULTS

Utilizing the optimized formulation, the Ca(OH)₂ NPs had an average size below 200 nm and polydispersity index lower than 0.2, along with a highly negative zeta potential and suitable entrapment efficiency percentage. The spherical morphology of the Ca(OH)₂ NPs was confirmed using TEM. The results of the XRD, FTIR and DSC revealed no interactions and confirmed that the drug was encapsulated inside the NPs. The drug release profile of the Ca(OH)₂ NPs exhibited a prolonged steady release that remained stable up to 48 h with higher concentrations than the free Ca(OH)₂. After examination by confocal laser scanning microscopy, Ca(OH)₂ NPs had a significantly greater depth and area of penetration inside dentinal tubules compared with the free drug.

CONCLUSIONS

Ca(OH)₂-loaded PLGA NPs were successfully optimized and characterized. The NPs exhibited a prolonged drug release profile and superior penetration inside dentinal tubules of extracted teeth when compared to Ca(OH)₂ .

Postoperative pain in endodontic retreatment of one visit versus multiple visits: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The aim of this systematic review and meta-analysis (SRM) was to assess the postoperative pain (PP) after non-surgical endodontic retreatment (NSER) in a one visit compared to multiple visits. The PICO question used was "Does NSER in patients with unsatisfactory endodontic treatment in a one-visit visit have a similar PP to that of NSER in multiple visits?"

MATERIALS AND METHODS

This systematic review followed PRISMA and was registered in PROSPERO (CRD42019136700). Searches were performed in the PubMed/MEDLINE, Scopus, and the Cochrane Library databases for articles published until September 2020. The eligible criteria were randomized clinical trials (RCTs). The meta-analysis was based on the Mantel-Haenszel. The PP after the retreatment was analyzed using a dichotomous outcome, measured according to risk ratio (RR) when p < 0.05. The Cochrane scale was used to assess risk of bias, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the quality of evidence.

RESULTS

Four studies were included. In general analysis without considering intensity, one-visit NSER presented lower PP than the multiple visits only for 1 and 30 days [(RR = 0.67; CI: 0.48 to 0.93; p = 0.02), and (RR = 0.09; CI: 0.01 to 0.66; p = 0.02)], respectively. Regarding sub-analysis considering the intensity, one visit present lower mild PP when compared with multiple visits [(RR = 0.54; CI: 0.30, 0.96; p = 0.04); (RR = 0.33; CI: 0.12, 0.88; p = 0.03); and (RR = 0.12; CI: 0.02, 0.86; p = 0.03)], respectively. However, sub-analysis for moderate and severe PP showed no significant difference, independently of period evaluated (p > 0.05). Regarding the risk of bias analysis, a low risk was observed for most domains, except allocation that was considered unclear, while the certainty of evidence for each analysis was considered low.

CONCLUSION

Within the limitations of study, the one and multiple visit can be considered adequate, because both present a similar occurrence of PP, except for mild pain. However, due to the low number of studies, further well conducted and standardized RCTs are needed to reassess these results.

CLINICAL RELEVANCE

Both therapies of endodontic retreatment can be considered in clinical practice. Therefore, the endodontist must consider the patient's individual characteristics and experience to consider the best treatment approach.

Assessment of extracting molars and premolars after root canal treatment: A retrospective study

Background

The loss of dentition after root canal treatment is a multifactorial entity which might differ between different teeth. The extraction can be more critical, as well as the rehabilitation options.

Aim

To analyze if the etiology of extracting root canal treated teeth is different between premolars and molars.

Materials and methods

The study included a total of 403 cases with non-surgical root canal therapy (NSRCT) and crown coverage that was referred to the oral surgery clinic for extraction. Tooth type, patient’s age, gender, time since treatment completion, and the reason for extractions were recorded and analyzed.

Results

The most frequently extracted teeth were molars (55.6%), followed by premolars (30.3%) and anterior teeth (14.1%). The reasons for extraction were subgingival decay (SGD) (62.5%), vertical root fractures (VRF) (25.3%), and patient demands after uncomfortableabscess discharge (12.2%). Most of the teeth survived between 13 and 36 months after NSRCT. The statistical power of 0.92 was demonstrated, and a P-value of less than 0.05 presented significant correlations.

Conclusion

Molars were extractedafter NSRCT due to SGD followed by premolars, which were extracted due to VRF. Special care should be taken while planning NSRCT treatment for molars, in particular, with emphasis on the importance of oral hygiene and follow-up visits.

Novel Endodontic Disinfection Approach Using Catalytic Nanoparticles

INTRODUCTION

The aim of this study was to test a new disinfection technology using biomimetic iron oxide nanoparticles (IO-NPs) with peroxidaselike activity to enhance antibacterial activity on root canal surfaces and in dentinal tubules.

METHODS

The canal surfaces and dentinal tubules of single-rooted intact extracted teeth were infected by growing Enterococcus faecalis biofilms for 3 weeks. The samples were divided into 6 treatment groups: (1) phosphate-buffered saline (PBS) (negative control), (2) 3% hydrogen peroxide (H₂O₂) (test control), (3) IO-NPs (0.5 mg/mL) (test control), (4) IO-NPs (0.5 mg/mL) + 3% H₂O₂, (5) 3% sodium hypochlorite (positive control), and (6) 2% chlorhexidine (positive control). Environmental scanning electron microscopy coupled with energy-dispersive spectroscopy was used to confirm IO-NPs binding to the canal surface after a single treatment. Specimens were labeled with fluorescent staining for live/dead cells, and confocal laser scanning microscopy was used for the quantification of dead bacteria relative to the negative control (PBS).

RESULTS

Both biofilm formation and dentinal tubule infection were successfully recapitulated using the in vitro model. IO-NPs were capable of binding to the infected canal surfaces despite a single, short-term (5-minute) treatment. IO-NP activation of H₂O₂ killed significantly more E. faecalis present on the canal surfaces and at different depths of dentinal tubules when compared with all other experimental groups (P < .05-.0005).

CONCLUSIONS

The results reveal the potential to exploit nanocatalysts with enzymelike activity as a potent alternative approach for the treatment of endodontic infections.

Laser-based Disinfection of the Root Canal System: An Update

Microorganisms have been considered to have played a critical role in the initiation and development of pulpo-periapical diseases. Some evidences have shown that mechanical instrumentation may leave considerable portions of canal surfaces undebrided. Therefore, some supplemental methods, such as the use of chemical solutions and/or lasers, have been introduced to further disinfect the complicated canal anatomy and destroy as many microorganisms as possible. The purpose of this review was to address a brief review of characteristics of lasers and their effects to disinfect the root canal in endodontics.

Controversies in Endodontics

Diseases of the dental pulp often have an infectious origin, and treatments are aimed to control infections of the root canal system. Endodontic treatment principles originally evolved on the basis of trial and error, and only in recent decades have scientific methods been adopted to support clinical strategies. Yet, relevant research on the disease processes, their diagnoses, and efficient treatment are rare in the endodontic literature. Hence, the advancement of biologically based knowledge significant to clinical endodontics has been slow. Therefore, many differences of opinion still prevail in this field of dentistry. This review highlights and analyzes the background of some of the more heavily debated issues in recent years. Specifically, it deals with disagreements regarding the clinical management of pulpal exposures by caries in the adult dentition, definitions of success and failure of endodontic therapy, and causes of and measures to control infections of the root canal system. Clearly, a most apparent gap in the published endodontic literature is the lack of randomized clinical trials that address the more significant controversial matters relating to the management of pulpal wounds, medication, and the number of appointments required for the treatment of infected root canals. However, trials in endodontics require extremely long follow-up periods if valid conclusions are to be generated. Therefore, it is not to be expected that there will be rapid solutions to these issues in the foreseeable future.

Strength of recommendation for single-visit root canal treatment: grading the body of the evidence using a patient-centred approach

AIM

To identify, search for and critically interpret the results from clinical studies on single- versus multiple-visit root canal treatment in the light of an evidence-based paradigm. For that purpose, the quality of the available body of evidence was assessed using the SORT 'grade' - Strength of Recommendation Taxonomy.

METHODOLOGY

A protocol was followed including all aspects of the review methods: (i) search strategy, (ii) inclusion criteria for studies, (iii) screening methods, (iv) quality assessment, (v) data synthesis of the selected studies, and (vi) the assessment of quality of the body of evidence available by the means of the SORT 'grade'. An extensive search of recent biomedical literature was performed in PubMed (up to May, 2014), EMBASE (dating from 1980 to May 2014) and Cochrane databases with appropriate headings and keywords related to single- and multiple-visit root canal treatment. Selected studies were stratified according to their level of evidence using the SORT criteria: (i) quality - Level A high-quality evidence, Level B medium/low-quality evidence and Level C no evidence; (ii) degree of consistency - consistent, when most studies found a similar conclusion, or inconsistent, when there was considerable variation amongst study findings.

RESULTS

After the digital and manual searches, 246 studies were indentified. Two hundred and seven studies were eliminated by exclusion criteria, resulting in a yield of 39 articles that were selected for retrieval. Of the 39 articles, only 11 could be classified as Level 2 (B); the other 28 articles did not obey the criteria to be considered as real patient-oriented evidence; thus, they were classified as Level 3 (C). No studies were ranked as Level 1 because they did not obey the minimum standard to be considered as both good-quality research and patient-oriented evidence. Despite this, all of the selected Level B studies reported no significant differences between single- and multiple-visit treatments.

CONCLUSION

There is B-level (mid-level) evidence to confirm there is no difference between the two different treatments, based on research addressing clinical outcomes and using some consistent but limited-quality methods of scientific investigation. More studies focused on evaluating patient-centred outcomes are urgently required.

Antibiofilm activity of three irrigation protocols activated by ultrasonic, diode laser or Er:YAG laser in vitro

AIM

To investigate the impact of three irrigation protocols, activated by three different methods, on mature biofilms of Enterococcus faecalis in vitro.

METHODOLOGY

Root canals in 280 single-rooted teeth were instrumented using a rotary Ni-Ti system. Biofilms of E. faecalis were generated based on a previously established protocol. Samples were randomly divided into three experimental (n = 80) and one control (n = 40) group based on the irrigation protocol employed: group 1 (NaOCl + Etidronic acid), 1 : 1 mixture of 6% NaOCl and 18% etidronic acid; group 2 (NaOCl-EDTA), 3% NaOCl followed by 17% EDTA; group 3 (NaOCl-EDTA-NaOCl), 3% NaOCl followed by 17% EDTA and a final flush of 3% NaOCl. Saline served as the control. Samples were further divided into four subgroups (n = 20) based on the activation method: subgroup A, no activation; subgroup B, ultrasonic activation; group C, diode laser; group D, Er:YAG laser. Confocal laser scanning microscopy was used to assess bacterial viability in situ. Root dentine powder was obtained for determining the colony-forming units (CFU mL(-1) ). Data were analysed by appropriate statistical analyses with P = 0.05.

RESULTS

All experimental irrigation protocols caused complete destruction of the biofilm in the root canal lumen. Within the dentinal tubules, all groups had a significantly higher percentage of dead bacteria than the saline control (P < 0.05). There was no significant difference between NaOCl + etidronic acid and NaOCl-EDTA-NaOCl (P > 0.05), whereas both groups brought about more bacterial reduction than NaOCl-EDTA (P < 0.05). There was no significant difference between diode laser and Er:YAG laser in any of the groups (P > 0.05). Both diode and Er:YAG laser were more effective than ultrasonic activation and conventional syringe irrigation in reducing E. fecalis biofilms (P < 0.05).

CONCLUSIONS

The use of NaOCl after or in combination with a chelator caused the greatest reduction of E. faecalis. Diode laser and Er:YAG laser activation were superior to ultrasonics in dentinal tubule disinfection.

Management of failed periodontal surgical intervention for a furcal lesion with a nonsurgical endodontic approach

As long as the prognosis of teeth remains a matter of concern, the endodontic-periodontal relationship will be considered a challenge for the clinician. Many etiologic factors, including bacteria, fungi, and viruses, plus other contributing factors, such as trauma, root resorptions/perforations, and dental malformations, play a role in the co-occurrence of endodontic and periodontal lesions. Whatever the cause, a correct diagnosis on which to base the treatment plan is the key to successful maintenance of the tooth. This article reports the successful endodontic management of a furcation lesion in a mandibular molar that was nonresponsive to a previous periodontal surgical graft. The case had presented a diagnostic challenge for the clinicians, and this article reviews the key points that can lead to a correct diagnosis and treatment planning.

Effectiveness of propolis and calcium hydroxide as a short-term intracanal medicament against Enterococcus faecalis: a laboratory study

The aim of this study was to investigate the antimicrobial activity of propolis-based intracanal medicament against Enterococcus faecalis using infected dentine models, and to compare its antimicrobial efficacy with that of the non-setting calcium hydroxide paste when used as a short-term medication for 1 and 2 days. A total of 50 dentine discs of 7-mm length was obtained from extracted human teeth. Five dentine discs were kept sterile to serve as a negative control. The remaining 45 were contaminated with E. faecalis and divided into two groups (n = 20) in addition to five discs that served as a positive control. The discs were treated as follow: 20 discs were filled with propolis, while the other 20 discs were filled with non-setting calcium hydroxide. Microbiological sampling was performed utilising sterile paper point, headstrom file and disc immersion. Results showed that propolis was significantly more effective than non-setting calcium hydroxide against E. faecalis after short-term application, which made comparison from this prospect unlevelled. The most effective microbiological sampling technique was abrading the lumen with headstrom file. Propolis is very effective as intracanal medicament in rapidly eliminating E. faecalis ex vivo.

Endodontic malpractice claims in Denmark 1995-2004

AIM

To study the reasons for and outcome of malpractice claims handled by the regional and national Danish Dental Complaint Boards (DCB) from 1995 to 2004. Specific attention was paid to endodontic claims. Three hypotheses were explored: endodontic malpractice claims are frequent, they are mostly due to technical shortcomings and male dentists are overrepresented.

METHODOLOGY

The reasons for the claims were classified and assigned to at least one of 14 categories. Cases assigned to the 'endodontic treatment' category were further sub-categorized, and reasons for malpractice were examined. An age and gender analysis of dentists and complaining patients was performed only on data obtained from the endodontic cases.

RESULTS

Overall, 3611 malpractice claims were registered. In 43% of the cases the dentist was judged to be guilty of malpractice. In the majority of the appealed cases the original verdict was affirmed (62.2%) by the national DCB. After crown & bridge treatment (23%) endodontic treatment was the next frequent malpractice claim (13.7%), in which 'technical complications or incorrect treatment' was the most frequent sub-categorization (28.4%). Reasons for endodontic malpractice verdicts were related to root filling quality, the use of a paraformaldehyde product and instrument fracture. Male dentists were most often involved in an endodontic claim, and the majority of complainants were females.

CONCLUSIONS

Endodontic malpractice claims were relatively common in Denmark. Perceived technical shortcomings dominated the patients' complaints concerning root canal treatment. Male dentists and female patients were overrepresented indicating a gender influence on aspects of the doctor-patient communication important for liability claims.

Single Visit versus Multiple Visit Root Canal Therapy

Aim: The purpose of this study was to determine clinical success rate of single visit verses multiple visit root canal treatment in cariously exposed vital primary molars.

Material& methods: 40 children in age group of 4 to 7 years were divided equally into two treatment groups and recall visits were carried out after one week, one month and three months and six months.

Results: Statistically no significant difference was found.

Conclusion: Multiple visit and single visit root canal treatment demonstrated almost equal success but most important aspect for success in pulpectomy cases is the indication of each case and then its subsequent treatment, be it multiple or single visit root canal treatment.

The prevalence of postoperative pain and flare-up in single- and multiple-visit endodontic treatment: a systematic review

AIM

The aim of this systematic review was to assess the evidence regarding postoperative pain and flare-up of single- or multiple-visit root canal treatment.

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 Science Citation Index to identify potentially relevant subsequent primary research.

REVIEW METHODS

The included clinical studies compared the prevalence/severity of postoperative pain or flare-up in single- and multiple-visit root canal treatment. Data in those studies were extracted independently.

RESULTS

Sixteen studies fitted the inclusion criteria in the review, with sample size varying from 60 to 1012 cases. The prevalence of postoperative pain ranged from 3% to 58%. The heterogeneity amongst included studies was far too great to conduct meta-analysis and yield meaningful results.

CONCLUSION

Compelling evidence indicating a significantly different prevalence of postoperative pain/flare-up of either single- or multiple-visit root canal treatment is lacking.

Immediate root canal disinfection with ultraviolet light: an ex vivo feasibility study

OBJECTIVE

The study was designed to test application of ultraviolet light to root canal walls, as a mean of complementary immediate disinfection after the use of sodium hypochlorite.

STUDY DESIGN

Root canals were infected ex vivo with Enterococcus faecalis for 48 hours. Non-attached bacteria were washed away, and the remaining attached bacteria were subjected to disinfection, with 5% sodium hypochlorite alone or followed by exposure to ultraviolet light (254 nm, 300 mJ/cm(2)). Root canals were then tested for remaining viable bacteria. Canals were obturated and tested again after 14 days.

RESULTS

Sodium hypochlorite alone achieved negative cultures in only 47% of the cases, but 96% was achieved with sodium hypochlorite followed by ultraviolet light (P < .001). This status was also maintained after 14 days.

CONCLUSIONS

Illumination of root canals with ultraviolet light may be an effective supplementary means to achieve immediate disinfection of infected root canals.

Evaluation of the antibacterial substantivity of several intra-canal agents

The aim of this in vitro study was to compare the antimicrobial substantivity of 2% chlorhexidine gluconate (CHX), 100 mg ml(-1) doxycycline and 2.6% sodium hypochlorite (NaOCl) in bovine root dentine. Eighty dentine tubes prepared from bovine incisors were infected in vitro for 14 days with Enterococcus faecalis. The specimens were divided into five groups as follows: doxycycline HCl; CHX; NaOCl; infected dentine tubes (positive control); and sterile dentine tubes (negative control). Dentine chips were collected with round burs into tryptic soy broth. After culturing, the number of colony-forming units (CFU) was counted. In all experimental groups, the number of CFU was minimum in the first cultures, and the results obtained were significantly different from each other at any time period (P < 0.05). In the first culture, the NaOCl group and doxycycline HCl group showed the lowest and highest number of CFU, respectively. In each group, the number of CFU increased significantly by time-lapse (P < 0.05). In conclusion, the substantivity of CHX was significantly greater than NaOCl and doxycycline.

Sensitivity of oral bacteria to 254 nm ultraviolet light

AIM

To explore the sensitivity of bacteria commonly found in root canals to 254 nm ultraviolet (UV) light, either as individual cells or as participants of a bacterial multilayer.

METHODOLOGY

The sensitivity of oral bacteria, as individual cells, to UV light was tested by subjecting plates streaked with bacteria to 254 nm UV, at a fluence of 1-20 mJ cm(-2). An experimental model was designed to produce a bacterial multilayer and to study absorption of UV light by bacteria in an outer layer and its effect on the elimination of bacteria in the inner layer.

RESULTS

Direct exposure to relatively low doses of UV light (2-7 mJ cm(-2)) effectively eliminated all bacterial strains tested. Furthermore, an Enterococcus faecalis strain, partially resistant to a 24 h exposure to calcium hydroxide, was effectively eliminated within several seconds of exposure to UV light (P < 0.001). UV was absorbed by a multilayer of bacteria. When 4 bacterial cells microm(-2) were present in the light path, the UV light dose had to be increased by a factor of x10 to achieve 100% elimination of the bacteria in an inner layer.

CONCLUSIONS

The application of UV light to eliminate endodontic pathogens may be possible. Nevertheless, its absorbance by outer layers of bacteria should be considered and the UV light dose adapted accordingly.

One-visit versus multiple-visit endodontic therapy — a review

A growing perception in endodontic circles is that root canal therapy requires one treatment visit only. One-visit endodontics offers many potential advantages. It is less time-consuming, resulting in less cost for the patient, potentially more profit for the dentist, less painful and less traumatic than multi-visit treatment. Conversely, if the pulp is necrotic and/or associated with periradicular disease, the root canal system is infected. In these cases, the root canal system should ideally be cleaned, an intracanal medication placed, and the canal filled at a second visit. In this paper we aim to review several aspects of one-visit versus multi-visit endodontic treatment and future perspectives in this field.

Consequences of and strategies to deal with residual post-treatment root canal infection

Bacterial sampling of prepared root canals is used to determine the presence and character of the remaining microbiota. However, it is likely that current sampling techniques only identify organisms in the main branches of the root canal system whereas it is unlikely that they can sample areas beyond the apical end-point of preparation and filling, or in lateral canals, canal extensions, apical ramifications, isthmuses and within dentinal tubules. Thus, it may be impossible by current techniques to identify residual post-treatment root canal infection. In histologic observations of root apices, bacteria have been found in inaccessible inter-canal isthmuses and accessory canals often in the form of biofilms. There is no in vivo evidence to support the assumption that these bacteria can be entombed effectively in the canal system by the root filling and thus be rendered harmless. As a consequence of this residual root infection, post-treatment apical periodontitis, which may be radiographically undetectable, may persist or develop as a defence mechanism to prevent the systemic spread of bacteria and/or their byproducts to other sites of the body. Histologic observation of root apices with surrounding bone removed from either patients or human cadavers has demonstrated that post-treatment apical periodontitis is associated with 50-90% of root filled human teeth. Thus, if the objective of root canal treatment is to eliminate apical periodontitis at a histological level, current treatment procedures are inadequate. It is essential that our knowledge of the local and systemic consequences of both residual post-treatment root infection and post-treatment apical periodontitis be improved. The continued development of treatments that can effectively eliminate root infection is therefore a priority in clinical endodontic research. Post-treatment disease following root canal treatment is most often associated with poor quality procedures that do not remove intra-canal infection; this scenario can be corrected via a nonsurgical approach. However, infection remaining in the inaccessible apical areas, extraradicular infection including apically extruded dentine debris with bacteria present in dentinal tubules, true radicular cysts, and foreign body reactions require a surgical intervention.

Incidence of periapical lesions and clinical symptoms after pulpectomy—A clinical and radiographic evaluation of 1- versus 2-session treatment

OBJECTIVE

Outcome of pulpectomy in 2 treatment sessions with calcium hydroxide as an intracanal dressing was compared to a procedure comprising instrumentation and root-filling in 1 session.

STUDY DESIGN

Subjects with a vital pulp condition (N = 256) were recruited to a randomized clinical trial. Outcome parameters included radiographic signs of apical periodontitis and painful symptoms at clinical follow-ups 1 week and 1-3 years after treatment.

RESULTS

Of 244 subjects available for final recall, 17 presented with periapical radiolucency. Lesions were evenly distributed among the 2 treatment groups. Postoperative pain recorded 1 week after permanent filling was significantly associated with overfilling (P = .001), with no difference between treatment groups. There was no association with presence of overfilling and radiographic lesion at end point of recall.

CONCLUSIONS

Study confirms that pulpectomy may be carried out at a high rate of success if due attention is given to aseptic operating procedures, proper instrumentation and filling. Under these conditions an interappointment dressing with calcium hydroxide does not seem to influence outcome.

Microbial status of apical root canal system of human mandibular first molars with primary apical periodontitis after “one-visit” endodontic treatment

OBJECTIVE

To assess the in vivo intracanal microbial status of apical root canal system of mesial roots of human mandibular first molars with primary apical periodontitis immediately after one-visit endodontic treatment. The residual intracanal infection was confirmed by correlative light and transmission electron microscopy.

STUDY DESIGN

Sixteen diseased mesial roots of mandibular first molars were treated endodontically, each in one visit. Mesio-buccal canals were instrumented using stainless steel hand files and mesio-lingual canals with a nickel-titanium rotary system. The canals were irrigated with 5.25% sodium hypochlorite (NaOCl) during the instrumentation procedures, rinsed with 10 mL of 17% ethylenediamine tetraacetic acid (EDTA), and obturated with gutta-percha and zinc oxide eugenol cement. Thereafter, the apical portion of the root of each tooth was removed by flap-surgery. The specimens were fixed, decalcified, subdivided in horizontal plane, embedded in plastic, processed, and evaluated by correlative light and transmission electron microscopy.

RESULTS

Fourteen of the 16 endodontically treated teeth revealed residual intracanal infection after instrumentation, antimicrobial irrigation, and obturation. The microbes were located in inaccessible recesses and diverticula of instrumented main canals, the intercanal isthmus, and accessory canals, mostly as biofilms.

CONCLUSIONS

The results show (1) the anatomical complexity of the root canal system of mandibular first molar roots and (2) the organization of the flora as biofilms in inaccessible areas of the canal system that cannot be removed by contemporary instruments and irrigation alone in one-visit treatment. These findings demonstrate the importance of stringent application of all nonantibiotic chemo-mechanical measures to treat teeth with infected and necrotic root canals so as to disrupt the biofilms and reduce the intraradicular microbial load to the lowest possible level so as to expect a highly favorable long-term prognosis of the root canal treatment.

Microbiological Evaluation of One- and Two-Visit Endodontic Treatment of Teeth with Apical Periodontitis: A Randomized, Clinical Trial

The antimicrobial efficacy of endodontic procedures performed in one-visit (including a 10-min intraappointment dressing with 5% iodine-potassium-iodide) was compared with a two-visit procedure (including an interappointment dressing with calcium-hydroxide paste). Teeth with apical periodontitis (n = 96) were randomly assigned to either group. Root canal sampling and culturing were performed before and immediately after instrumentation, and after medication. Initial sampling demonstrated the presence of microorganisms in 98% of the teeth. Postinstrumentation sampling showed reduction of cultivable microbiota. Antibacterial dressing further reduced the number of teeth with surviving microbes. In the postmedication samples, residual microorganisms were recovered in 29% of the one-visit teeth and in 36% of the two-visit treated teeth. No statistically significant differences between the groups were discerned. It was concluded that from a microbiological point of view, treatment of teeth with apical periodontitis performed in two appointments was not more effective than the investigated one-visit procedure.

Bacteria recovered from teeth with apical periodontitis after antimicrobial endodontic treatment

Chávez de Paz LE, Dahlén G, Molander A, Möller A, Bergenholtz G. Bacteria recovered from teeth with apical periodontitis after antimicrobial endodontic treatment. International Endodontic Journal, 36, 500-508, 2003.

AIM

To determine whether there is a pattern for certain bacteria to remain after chemo-mechanical treatment of root canals in teeth with apical periodontitis.

METHODOLOGY

Consecutive root-canal samples of 200 teeth receiving root-canal treatment, referred from general practitioners and endodontic specialists for analyses of cultivable microbes, were studied prospectively. To be included, samples had to be taken at a treatment session subsequent to the one at which endodontic therapy was initiated. All samples were from teeth that either presented with clinical or radiographic evidence of apical periodontitis or both. Bacteriological findings were linked to clinical and radiographic parameters including status of the root canal prior to treatment, namely, vital pulp, necrotic pulp or root filled.

RESULTS

A total of 248 strains were isolated from 107 teeth giving bacterial growth. Gram-positives predominated (85%). Lactobacillus spp. (22%), nonmutans streptococci (18%), and Enterococcus spp. (12%) were the most common isolates. Gram-negative anaerobes were relatively sporadic. Large radiographic bone lesions, persistent pain and use of intracanal calcium hydroxide dressing correlated with bacterial presence (P < 0.05).

CONCLUSIONS

Once established, nonmutans streptococci, enterococci and lactobacilli appear to survive commonly following root-canal treatment of teeth with clinical and radiographical signs of apical periodontitis.