Calculus-like deposit on the apical external root surface of teeth with post-treatment apical periodontitis: report of two cases

Non-surgical root canal treatment and retreatment versus apical surgery in treating apical periodontitis: A systematic review

BACKGROUND

In addition to non-surgical root canal treatment or retreatment, apical surgery may be carried out to manage teeth with apical periodontitis. However, it is unclear which treatment option is more effective.

OBJECTIVE

To systematically review the effectiveness of apical surgery compared with non-surgical treatment or retreatment in terms of clinical and patient-related outcomes in teeth with apical periodontitis.

METHODS

A literature search of electronic databases, the grey literature, the reference lists of included articles and previous reviews, and a hand search of leading endodontic journals, was conducted. Randomised and non-randomised control trials, and longitudinal observational studies on patients undergoing surgical (treatment group) and non-surgical root canal treatment or retreatment (control group) of teeth with apical periodontitis were included. The risk of bias was appraised using the Cochrane risk-of-bias tool; ROBINS-I and the Newcastle-Ottawa Scale.

RESULTS

Five studies, consisting of two randomised clinical trials, two non-randomised clinical trials, and a retrospective cohort study, were included. The interobserver agreement was high and kappa correlation coefficient was good. In total 529 teeth were available for follow-up that varied from 6 months to 8.7 years. The overall risk of bias was high for four studies and raised some concerns in one study. Apical surgery showed seemly better results regarding periapical healing and less need for more and further intervention, although tooth survival was higher in the control group. Given the heterogeneity of the studies, meta-analysis was not possible.

DISCUSSION

Previous systematic reviews have conducted an indirect comparison by separately pooling the outcomes of studies analysing either non-surgical, or surgical, treatment. In this systematic review, only studies that compared both treatments were included. Most results of this and previous reviews were similar.

CONCLUSION

No treatment option showed clear superiority. However, to arrive at statistically supported conclusions there is a need for additional high-quality comparative trials.

REGISTRATION

PROSPERO database (Registration number CRD42021260300).

Surgical management of a lateral lesion refractory to root canal retreatment caused by an extraradicular calculus. A case report

This article describes the management of a root canal-treated maxillary central incisor displaying a radiographic lateral radiolucency and a sinus tract that persisted irrespective of root canal retreatment following high standards. Endodontic microsurgery was indicated and curettage of the pathologic tissue revealed a calculus-like material attached to the outer root surface around the exit of a large lateral canal. A non-conventional approach was chosen: No root-end resection was conducted. Instead, the calculus was removed and the apical surface was scaled and smoothed, conserving the apical structure. Retrocavities were prepared in both lateral and apical foramens and filled with a bioceramic material. Follow-up examination showed optimal soft tissue healing. One-year follow-up of radiographs revealed healing of the lateral lesion. The lesion was diagnosed as a cyst, with an infected lumen. An exuberant calculus-like material attached to the external root surface was the most likely cause of the recalcitrant lateral periradicular lesion.

Present status and future directions - microbiology of endodontic infections

Apical periodontitis has a microbial aetiology and is one of the most common inflammatory diseases that affect humans. Fungi, archaea and viruses have been found in association with apical periodontitis, but bacteria are by far the most prevalent and dominant microorganisms in endodontic infections. Bacterial infection of the root canal system only occurs when the pulp is necrotic or was removed for previous treatment. In some specific cases, including acute and chronic abscesses, the bacterial infection may reach the periradicular tissues. Intracanal bacteria are usually observed as sessile multispecies communities (biofilms) attached to the dentinal root canal walls. Infection in the main root canal lumen can spread to other areas of the root canal system. Although more than 500 bacterial species have been detected in endodontic infections, a selected group of 20 to 30 species are most frequently detected and may be considered as the core microbiome. There is a high interindividual variability in the endodontic microbiome in terms of species composition and relative abundance. Obligate anaerobic species are more abundant in the intraradicular bacterial communities of teeth with primary apical periodontitis, while both anaerobes and facultatives dominate the communities in post-treatment apical periodontitis. Bacterial interactions play an essential role in determining the overall virulence of the community, which has been regarded as the unit of pathogenicity of apical periodontitis. This article reviews the microbiologic aspects of endodontic infections and provides perspectives for future research and directions in the field.

Endodontic biofilms: contemporary and future treatment options

Apical periodontitis is a biofilm-mediated infection. The biofilm protects bacteria from host defenses and increase their resistance to intracanal disinfecting protocols. Understanding the virulence of these endodontic microbiota within biofilm is essential for the development of novel therapeutic procedures for intracanal disinfection. Both the disruption of biofilms and the killing of their bacteria are necessary to effectively treat apical periodontitis. Accordingly, a review of endodontic biofilm types, antimicrobial resistance mechanisms, and current and future therapeutic procedures for endodontic biofilm is provided.

Effects of a Chimeric Lysin against Planktonic and Sessile Enterococcus faecalis Hint at Potential Application in Endodontic Therapy

Enterococcus faecalis is a commensal opportunistic pathogen found in the intestine, mouth, and vaginal tract of humans. As an invasive pathogen in the oral cavity, E. faecalis is one of the leading causes of periapical endodontic lesions. However, due to the strong biofilm-forming capacity and tolerance of E. faecalis to conventional antibiotics and treatments, limited therapeutic options are available. In the present study, we investigated the activity of ClyR, a chimeric lysin with extended streptococcal lytic spectrum, against planktonic and sessile E. faecalis cells in vitro and in an ex vivo dental model. Our results showed that ClyR has robust and rapid lytic activity against multiple E. faecalis strains, killing >90% planktonic cells within 1 min at a concentration of 50 μg/mL. The biochemical experiments combined with microscopy analysis revealed that ClyR degrades E. faecalis biofilm with high efficacy in a dose-dependent manner, reducing the survival rate to <40% within biofilms after treatment with 50 μg/mL ClyR for 1 h. In the ex vivo dental model, ClyR showed a significant biofilm removal efficacy, killing >90% viable bacteria within biofilms at a low dose of 50 μg/mL, which is much better than ampicillin and similar to calcium hydroxide, the extensively used routine intracanal medicament in the treatment of endodontics and dental traumatology. The robust activity of ClyR against both planktonic and sessile E. faecalis suggests the potential of ClyR in treating endodontic infections caused by E. faecalis.

Histobacteriologic Conditions of the Apical Root Canal System and Periapical Tissues in Teeth Associated with Sinus Tracts

INTRODUCTION

This histobacteriologic study described the pattern of intraradicular and extraradicular infections in teeth with sinus tracts and chronic apical abscesses.

METHODS

The material comprised biopsy specimens from 24 (8 untreated and 16 treated) roots of teeth associated with apical periodontitis and a sinus tract. Specimens were obtained by periradicular surgery or extraction and were processed for histobacteriologic and histopathologic methods.

RESULTS

Bacteria were found in the apical root canal system of all specimens, in the main root canal (22 teeth) and within ramifications (17 teeth). Four cases showed no extraradicular infection. Extraradicular bacteria occurred as a biofilm attached to the outer root surface in 17 teeth (5 untreated and 12 treated teeth), as actinomycotic colonies in 2 lesions, and as planktonic cells in 2 lesions. Extraradicular calculus formation (mineralized biofilm) was evident in 10 teeth.

CONCLUSIONS

Teeth with chronic apical abscesses and sinus tracts showed a very complex infectious pattern in the apical root canal system and periapical lesion, with a predominance of biofilms.

Scanning electron microscopic examination of resected root apices obtained from endodontic microsurgery

This study was designed to examine the morphological features of the resected root apices obtained from endodontic microsurgery using a scanning electron microscope (SEM) as well as their anatomical effect on the clinical outcome of the surgical treatment. One-hundred-six resected root apices from 91 patients/surgeries were obtained by endodontic microsurgery, and fixed immediately for storage. The resected apices were prepared for SEM to examine their morphological features, such as the number and size of the apical foramina. The patients were periodically checked up at least 1 year and the clinical outcome of the microsurgery was judged as a success or failure according to the Molven's criteria. The SEM findings and the clinical outcome of apical surgery were evaluated to see any potential correlation between them. The SEM examination revealed that 60.4% of specimens had more than two portals of exit on the resected root apices and the size of the major foramen was at least 386 micrometer and 334 micrometer from maxillary and mandibular molar, respectively. With a recall rate of 72.9%, 91.9% of the surgical cases were decided to have successful outcomes. Based on this SEM study, a relatively high frequency of multiple portals of exit was existed and the sizes of major foramina were bigger than that were reported in previous reports. The clinical outcomes of endodontic microsurgery were not correlated with the anatomical features of resected apical root apices. SCANNING 38:455-461, 2016. © 2016 Wiley Periodicals, Inc.

Complex Apical Intraradicular Infection and Extraradicular Mineralized Biofilms as the Cause of Wet Canals and Treatment Failure: Report of 2 Cases

This article describes 2 cases that showed persistent intracanal exudation (wet canal) even after several visits of antimicrobial endodontic treatment. Histologic and histobacteriologic investigation was conducted for determination of the cause. The 2 cases involved teeth with apical periodontitis lesions, which presented persistent exudation refractory to treatment after several visits. In case 1, it was not possible to achieve a dry canal, and surgery had to be performed. In case 2, attempts to dry the canal succeeded and the canal was filled, but follow-up examination showed an enlarged apical periodontitis lesion and extraction was performed. Biopsy specimens consisting of the root apex and apical periodontitis lesion for case 1 and the whole root for case 2 were subjected to histologic and histobacteriologic analyses. Both cases showed complex bacterial infection in the apical root, affecting both the intraradicular space and the outer root surface. Case 1 showed bacterial biofilms in ramifications, on untouched walls, and extending to the external root surface to form a thick and partially mineralized structure with high bacterial density. Different bacterial morphotypes were evidenced. Case 2 had a ledge on the apical canal wall created during instrumentation, which was filled with necrotic debris, filling material, and bacteria. The walls of the apical portion of the canal were covered by a bacterial biofilm, which was continuous with a thick extraradicular biofilm covering the cementum and dentin in resorptive defects. The extraradicular biofilm showed areas of mineralization and was dominated by filamentous bacteria. The 2 cases with wet canals and treatment failure were associated with complex persistent infection in the apical part of the root canal system extending to form thick and partially mineralized biofilm structures (calculus) on the outer apical root surface.

Migratory and misleading abscess of oro-facial region

Acute pericoronitis usually presents with severe localized pain, swelling and sometimes trismus. However, chronic pericoronitis and periodontal abscess produce a dull pain, moderate swelling and are occasionally seen migrating into distant sites producing fistulae intra-orally and/or extra-orally. This may quite often cause diagnostic dilemmas necessitating thorough medical and dental history, careful clinical examination and sometimes special investigations to confirm the etiology and or origin of infection. Here, we present three such cases and their management.

Analysis of the secondary endodontic lesions focusing on the extraradicular microorganisms: an overview

The present study aimed at reviewing the literature on extraradicular infections of endodontically treated teeth, summarizing the main hypotheses on etiopathogenesis and describing the most suitable techniques to identify the composition of pathogenic extraradicular microorganisms. Medline database was searched using the keywords "Apical biofilm," "extraradicular infection," "secondary endodontic lesion," "endodontic retreatment," "biofilm" either alone or combined with AND. A further hand search was performed on the main endodontic journals. The most frequent bacterial species identified in different studies and with different techniques may vary considerably. Although the presence of some species of microorganisms seems to be determinant, the true origin of extraradicular infection is still undetermined. The literature analysis showed marked differences in methodology, materials, aims, and techniques adopted, which led to highly heterogeneous outcomes. The picture emerging from this review is that extraradicular infection is likely a multifactorial disease that requires further systematic investigation using standardized techniques.

Light activated disinfection: an alternative endodontic disinfection strategy

BACKGROUND

An improved light activated disinfection technique utilizing a specific photosensitizer formulation, liquid optical-conduit, oxygen-carrier and light energy of appropriate wavelength has been introduced recently. This study tested the efficacy of this improved light activated disinfection on ex vivo biofilms of Enterococcus faecalis at two different stages of maturation.

METHODS

Eighty-five tooth sections were prepared and endodontic biofilm of E. faecalis were grown within the root canal. In stage 1, conventional light activated disinfection (LAD), chemical disinfectant (sodium hypochlorite) and improved LAD were tested on four-day-old (immature) biofilms. In stage 2, conventional LAD, improved LAD and chemomechanical disinfection (alone and in combination with improved LAD) were tested on four-week-old (mature) biofilms.

RESULTS

Sodium hypochlorite and improved LAD showed the ability to significantly inactivate bacteria in four-day-old biofilms when compared to the control and LAD (p < 0.05). Inactivation of bacteria from deeper dentine was higher in improved LAD than sodium hypochlorite. In four-week-old biofilms, a combination of chemomechanical disinfection and improved LAD produced significant bacterial killing compared to either chemomechanical disinfection or improved LAD alone.

CONCLUSIONS

This study highlighted the potential of improved LAD to kill bacteria within dentinal tubules. In combination with chemomechanical preparation, the improved LAD significantly inactivated four-week-old biofilm bacteria.

Dens invaginatus in an immature maxillary lateral incisor: a case report of complex endodontic treatment

This case report presents the surgical endodontic treatment of an Oehlers Class II invaginated immature tooth. In this case, communication between the invagination and the pulp caused pulp necrosis, periapical inflammation, and cessation of root formation. The initial treatment goal was to achieve apexification and then fill both the root canal and the canal of the invagination. After a 6-month treatment with calcium hydroxide dressings, there was no healing radiographically and no sign of a hard tissue barrier in the apex. Periapical surgery with the placement of mineral trioxide aggregate (MTA) root-end filling was deemed successful at the 1-year recall. To treat dens invaginatus, both conventional and surgical endodontic treatment techniques should be considered. In dens invaginatus, conventional endodontic treatment modalities may be unsuccessful because of inadequate debridement and disinfection; however, subsequent periapical surgery and retrofilling with MTA may promote healing.

Healing response of apicomarginal defects to two guided tissue regeneration techniques in periradicular surgery: a double-blind, randomized-clinical trial

AIM

To compare healing responses to periosteal sliding grafts and polyglactin 910 periodontal mesh used as guided tissue regeneration (GTR) materials/techniques when both periapical and periradicular bone loss are present.

METHODOLOGY

Thirty patients with suppurative chronic apical periodontitis with apicomarginal communication were selected and allocated randomly into two groups according to the barrier technique to be used during periradicular surgery: periosteal graft group (n = 15) and bioabsorbable membrane group (n = 15). Clinical and radiological evaluations were completed prior to surgery, a week later and every 3 months after surgery up to 12 months to measure the periodontal pocket depth (PD), clinical attachment level (CAL), gingival margin position (GMP), size of periapical lesion, percentage reduction of the periapical rarefaction, and periapical healing.

RESULTS

Both groups showed highly significant (P < 0.001) reductions in periodontal PD, CAL and size of periapical lesion at 12 months whilst GMP was unaltered. No significant difference between the experimental groups was evident for these parameters, or for the percentage reduction of size of the periapical lesion and clinical-radiographic healing.

CONCLUSION

Guided tissue regeneration applied to apicomarginal defects using sliding periosteal grafts and use of bioabsorbable membranes led to similar enhancements of the clinical outcome of periradicular surgery in terms of periapical healing, gain of periodontal support, PD reduction and minimal recession of the gingival margin.

Enterococcus faecalis-mediated biomineralized biofilm formation on root canal dentinein vitro

Enterococcus faecalis is the most predominant bacteria in teeth with failed root canal therapy and is found to survive harsh conditions prevailing in the root canals of endodontically treated teeth. This study aims to investigate the interaction between E. faecalis and root canal dentine substrate. Towards this end, tooth specimens were prepared and divided into two groups. The tooth specimens in group 1 were incubated with E. faecalis for periods of 2-, 4-, and 6-week intervals and the chemical composition of the biofilm was determined using X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. The tooth specimens in group 2 were incubated with E. faecalis for a period of 6 weeks and the topography and ultrastructure of the biofilm were examined using scanning electron microscopy (SEM), light microscopy, and laser confocal scanning microscopy. The sediments formed from the bacterial interaction on the dentine (in group 1) were also examined by SEM and FTIR. These experiments highlighted different stages in the interaction of E. faecalis with root canal dentine. Further, a bacterial-induced apatite reprecipitation on mature biofilm was also observed. This ability of E. faecalis to form such calcified biofilm on root canal dentine may be a factor that contributes to their persistence after endodontic treatment.