Antimicrobial effect of MTAD, Tetraclean, Cloreximid, and sodium hypochlorite on three common endodontic pathogens.

OBJECTIVES: The aim of this in vitro study was to evaluate the antimicrobial action of BioPure MTAD (Dentsply Tulsa Dental, Johnson City, TN), Tetraclean, Cloreximid (a mixture of Chlorhexidine (CHX) digluconate and Cetrimide), and 5.25% NaOCl (Ogna Laboratori Farmaceutici, Milano, Italy) against selected endodontic pathogens (Enterococcus faecalis, Porphyromonas gingivalis, and Prevotella intermedia). MATERIALS AND METHODS: The agar plate diffusion procedure was used to observe the antimibrobial activity of irrigants. RESULTS: Statistical analysis revealed significant effects of the different irrigants on the bacteria colonies. Treatment with 5.25% NaOCl induced a larger zone of microbial inhibition in Prevotella intermedia and Porphyromonas gingivalis (Tukey HSD post-test, P = 0.0001) when compare to MTAD, Tetraclean and CHX. Anyway, MTAD and Tetraclean were more effective to inhibit bacterial growth compared to CHX (P < 0.0001, Tukey HSD post-test). Furthermore, post hoc analysis revealed that MTAD and Tetraclean induced the largest zone of microbial inhibition of Enterococcus faecalis cultured under both aerobic and anaerobic conditions, when compared with 2% CHX and NaOCl (P < 0.0001, Tukey HSD post-test). The control group showed no microbial inhibition. CONCLUSION: 5.25% NaOCl showed a high antimicrobial activity against anaerobic bacteria. MTAD and Tetraclean showed a high action against both, strictly anaerobic and facultative anaerobic bacteria. Chlorexidine + Cetrimide (Cloreximid) showed the lowest antibacterial activity against both, facultative and strictly anaerobic bacteria tested.

Comparative evaluation of antimicrobial efficacy of sodium hypochlorite, MTAD, and Tetraclean against Enterococcus faecalis biofilm.

The aim of this study was to compare the antimicrobial efficacy of 5.25% NaOCl, BioPure MTAD (Dentsply Tulsa Dental, Johnson City, TN), and Tetraclean (Ogna Laboratori Farmaceutici, Milano, Italy) against Enterococcus faecalis biofilm generated on cellulose nitrate membrane filters. After incubation, the membrane filters were transferred into tubes containing 5 mL of the selected antimicrobial solution test agent or NaCl 0.9% (positive control) and incubated for 5, 30, and 60 minutes at 20 degrees C. After each period of time, the test agents were vortexed for 60 seconds to resuspend the microorganisms. Ten-fold serial dilutions were generated in reduced transport fluid. Each dilution was plated onto a brain heart infusion plates. The plates were then incubated for 48 hours in an aerobic atmosphere at 37 degrees C and colony-forming units per membrane was calculated. Statistical analysis showed that only 5.25% NaOCl can disgregate and remove the biofilm at every time; however, treatment with Tetraclean caused a high degree of biofilm disgregation in every considered time intervals as compared with MTAD (T5 p < 0.05, T30 p < 0.01, and T60 p < 0.001).

Chondroid metaplasia in inflamed pulp tissue: a case report.

OBJECTIVE: The aim of the present report is to report an unusual case of chondroid metaplasia of the dental pulp. STUDY DESIGN: A white 45-year-old female patient appeared with signs and symptoms of an irreversible pulpitis on an upper left decayed third molar. After extraction, the tooth was fixed, demineralized, and processed for light microscopy. RESULTS: Pulp tissue was replaced at one of the pulp horns by a colliquative necrosis surrounded by neutrophil leucocytes and congested blood vessels. Serial sections demonstrated a complete opening of the decayed tooth to the oral environment, and an area of chondroid metaplasia of the pulp was evident. Chondroid tissue was surrounded by a dense concentration of chronic inflammation cells. CONCLUSIONS: According to the best knowledge of the authors, this is possibly the first report of an occurrence of chondroid metaplasia in the dental pulp. This metaplasia could be the result of an attempt at tissue repair by the pulp tissue injured by the carious lesion. The pathologic changes in the dental pulp could have activated some of the mechanisms that have been described in other tissues, producing the formation of chondroid tissue. Pulp tissue may adapt to changed environmental stimuli by a deviation from normal cell differentiation.

Aspergillus mycetoma of the maxillary sinus secondary to overfilling of a root canal.

In nonimmunocompromised patients aspergillosis of the paranasal sinuses is a relatively rare disease. Root canal treated teeth with overextension of the root canal sealer or solid materials such as gutta-percha or silver cones into the sinus might be the main etiological factor for aspergillosis of the maxillary sinus in healthy patients. Root-filling materials based zinc oxide-eugenol is considered to be a growth factor for aspergillus. Aspergillus fumigatus needs heavy metals such as zinc oxide for proliferation and metabolism. Prognostic and histological studies showed that instrumentation and obturation should not extend beyond the apical foramen. When the sealer and/or gutta-percha is extruded within the sinus, this produce an inflammatory reaction and then Aspergillus growth. We report one case of healthy 60-yr-old male with overextension of root canal sealer in maxillary sinus. After surgical procedure, microscopic examination revealed aspergillosis. Overextension into the maxillary sinus with root canal cements has to be avoided.

Russell bodies in dental pulp of permanent human teeth.

OBJECTIVES: We sought to characterize the prevalence of Russell bodies in specimens clinically diagnosed as pulpitis. STUDY DESIGN: Forty-five teeth with symptomatic irreversible pulpitis were extracted, fixed, and demineralized. Five nonsymptomatic human teeth extracted for orthodontic purposes were used as controls. All teeth were then processed for light microscopy, for which they were stained variously, or for transmission electron microscopy (TEM). RESULTS: There was no evidence of Russell bodies in the pulp of 5 nonsymptomatic human teeth. Russell bodies, however, were detected in 31/45 (69%) of pulpitis specimens examined by light microscopy. The basic stains safranin and fucsin gave better visualisation of them than other staining procedures. All pulpitis specimens were histologically characterized as having the features of chronic inflammation. Of 5 specimens of pulpitis teeth evaluated by TEM, all exhibited Russell bodies. There was no morphological distinction among the Russell bodies when view either by light or electron microscopy. These structures appeared either within rough endoplasmic reticulum (RER) or they were found in extracellular stroma, suggesting their association with the lysis of cells. CONCLUSIONS: Russell bodies are prevalent in pulpitis samples with histological features of chronic inflammation, but are not found in all such samples. Russell bodies may not have been frequently detected in the past due to the types of stains employed in histolopathological study of pulps. The mechanistic basis of the association of Russell bodies with the symptoms of irreversible pulpitis is not clear.