Tannerella forsythia detected in infected root canals using nested PCR.

PURPOSE: This study assessed the occurrence of Tannerella forsythia in patients with acute and chronic primary endodontic infections. METHODS: Clinical samples were collected from 40 patients with acute and chronic periradicular disease. Nested polymerase chain reaction (PCR) assay technique was used to detect the presence of T. forsythia in primary endodontic infections. The first round of PCR amplification used universal primers to detect the 16S rDNA sequence. Product from the first round was then used to amplify T. forsythia specific fragment with species-specific pairs of primers. RESULTS: T. forsythia was found in 12 of 27 chronic and 5 of 13 acute infected patients for an overall occurrence frequency of 42.5%. No significant correlation was found between patients with the T. forsythia positive genotype and the occurrence of clinical symptoms in the primary endodontic infections (P < 0.05) (P = 0.496). Also, no significant relationship was found between the occurrence of T. forsythia and the patient's age (P = 0.61) or gender (P = 0.239).

Bacterial aggregation in infected root canal.

The aim of this study was to investigate different microbial morphotypes in the root canal infection associated with chronic diffuse periapical lesion. In forty cases of asymptomatic teeth with radiographically diagnosed diffuse periapical lesion we took specimens of infected tissue from the root canals at the beginning of endodontic treatment. Fixation and four different staining methods of the specimens were obtained to provide microscope examination. All examined root canal specimens were heavily infected by bacteria. The most commonly identified were cocci 92 %, small mostly G+ diplococci and large G+cocci in clusters and grapelike groups, bacilli found in 67%, coccobacilli 37%, fungi 17%, and spirochetes in 5%.

Intraosseous injection of clindamycin phosphate into the chronic apical lesion of lower molar--a case report.

Periapical disease is the result of bacteria, their product, and the host response to them. Early histological studies of diseased periapical tissue have not been able to demonstrate viable bacteria in the lesions studied. Recent reports indicate that many of periapical lesions are indeed infected before and after endodontic treatment. The validity and applicability of the microbial delivery overcome many disadvantages that we see with systemic drugs. In this case report we presented a novel approach of managing chronic diffuse periapical lesion of lower molar based on specific selection of intracanal medicament in combination with direct periapical injection. We used bacterial culturing and antibiotic sensitivity test to select specific intracanal medicament, in addition we presented an intraosseous injection technique to locally deliver the selected medicament directly into the periapical lesion. Our findings are encouraging and promising. The validity and applicability of the technique needs to be tested in a well controlled clinical trial.

Endodontic-periodontal locally delivered antibiotics.

Endodontic pathology is a bacterial disease. It is well established that periapical disease is the result of bacteria, their product, and the host response to them. Periradicular disease will occur after microorganisms and their metabolic products affect the periradicular tissue. Aim of using antibiotics as part of a treatment regimen is to achieve, within the periodontal environment, a concentration of the drug that is sufficient either to kill (bactericidal) or arrest the growth (bacteriostatic) of pathogenic microorganisms. There are two possible approaches to improve the drug action: sustained and controlled drug release to reduce or eliminate side effects by improving the therapeutic index and site-specific drug delivery to minimize systemic effects. These two strategies have been explored by the association of drugs with different vehicles, either naturals or synthetics. A wide variety of specialized local delivery systems (i.e.intrapocket devices) have been designed to maintain the antibiotic in the GCF (gingival crevicular fluid) at a concentration higher than the MIC (minimum inhibitory concentration). Fibres, films, strips and microparticles made of biodegradable or non-biodegradable polymers have been reported as effective methods to administer antibacterial agents for periodontal therapy. Together with these solid devices, semisolid adhesive or non-adhesive formulations have also been proposed.

Etiological findings in endodontic-periodontal infections.

The endodontium and periodontium are closely related and disease of one may lead to secondary disease in the other. The differential diagnosis of endodontic and periodontal disease is of vital importance, so that the appropriate treatment can be done. Microorganisms play a primary role in endodontic and periodontal infections. The magnitude of the host response will be directly proportional to the virulence and the number of microbial cells present. Tissue damage caused by bacteria is mediated by either direct or indirect mechanisms. Direct harmful effects caused by bacteria involve their products, such as enzymes (collagenase, hyaluronidase, condroitinase, acid phosphatase), exotoxins and metabolites (bytrate, propionate, ammonium polyamines, sulphured compounds). In addition, bacterial components such as peptidoglycan, teichoic acid, fimbriae, outer membrane proteins, capsule, and lypopolysaccharide, stimulate the development of host immune reaction capable of causing severe tissue destruction.

Formulation ingredients for toothpastes and mouthwashes.

In order to achieve the multi-claim products required for the dental care category, it is necessary for the formulator to use a variety of different ingredients. This places a number of demands on the development process. Innovations in the areas of pharmaceutical technology have contributed to the formulation of the products having superior efficacy as well as other attributes that may contribute to clinical response and patient acceptability. Improved clinical efficacy and tolerability, along with conditioning signals, should encourage patient compliance with oral hygiene further complementing professional efforts directed at disease prevention. The most effective way of preventing the development of dental disease is in controlling the production of dental plaque. It is formed by microbial action. The removal of plaque from the teeth and related areas is essential for the maintenance of a healthy mouth. In this paper we have presented the main components of toothpastes and mouthwashes. For the active ingredients, their supposed effect as therapeutic agents is also explained.

Different digital imaging techniques in dental practice.

Different imaging techniques are used to pick up the signal of interest in digital sensors, including charge-coupled devices (CCD), complementary metal-oxide semiconductors (CMOS), photostimulable phosphors plates (PSP) and tuned-aperture computed tomography (TACT) Digital radiography sensors are divided into: storage phosphor plates (SPP) called photostimulable phosphor plates (PSP), silicon devices such as charge-coupled devices (CCD) or complementary metal oxide semiconductors (CMOS). Relatively new type of imaging that may hold advantage over current radiographic modalities is tuned-aperture computed tomography (TACT).

Clinical application of calcium hydroxide in dental pathology and endodontics.

Calcium hydroxide has a hard tissue inducing effect. It is a powder, that can be mixed with a physiological saline to a paste. The paste is highly alkaline with a pH 12.5 and its application to the pulp results in necrosis of the part of coronal pulp tissue shows no or only a milled inflammatory reaction. Analyzing the pH and the concentration of calcium ions in the periapical area, it is obvious that at least 2 weeks are necessary for calcium hydroxide bactericide activity. Calcium hydroxide retains its anti-bacterial properties for about two months when placed under a restoration, after which it degrades to calcium oxide and other less effective calcium salts. All calcium hydroxide preparations have a limited shelf life as they eventually turn into calcium oxide. Calcium hydroxide can be used as linings, for indirect and direct pulp cupping, root dressing, root canal sealant, apical closure. The vehicles play a supportive role, giving pastes chemical characteristics such as dissociation and diffusion as well as favoring the correct filling of the root canal which are decisive factors for antimicrobial potential and tissue healing. The mechanism of action of calcium hydroxide on tissues, inducing the deposition of mineralized tissue, is an extremely important aspect for the indication of calcium hydroxide, because it demonstrates biological compatibility of calcium hydroxide.