A recall program for the outcome of conventional root canal treatment performed in a teaching hospital.

OBJECTIVES: This study investigated the long-term survival and the prognostic factors of endodontic treatments performed in a dental teaching hospital. The aim was to calculate the probabilities of success or failure according to the follow-up extent and to assess the time allowed for a complete periapical healing. MATERIALS AND METHODS: A cohort of 185 teeth were re-examined 1-4 years after treatment. The outcome was assessed on the basis of radiographic and clinical criteria as success, uncertain or failure. A survival analysis using the Cox model was used (i) to explore tooth survival and periapical healing over the time and (ii) to highlight the predictive factors of treatment outcome. RESULTS: After 2 years, the appearance of an apical periodontitis remained lower than 3.5%, whereas only 22.8% of periapical healed cases were notified. The prognosis factors are: (i) for teeth with initial healthy periapical conditions, coronal leakage (p = 0.002) with the higher risk of failure (RR = 19.77), absence of correspondence filling length/shaping = 0.026), type of teeth (p = 0.041) and (ii) for teeth with apical periodontitis, number of root canals (p = 0.000,91), correspondence filling length/shaping length (p = 0.017) and over-filling (p = 0.09). New periapical lesions or tooth loss were recorded after 2 years. Half of the successful cases of periapical healing were observed during the follow-up from 2-4 years. CONCLUSIONS: This longitudinal study shows that coronal leakage is responsible for late failure and that periapical healing is long to achieve. Therefore, endodontic treatments may require a follow-up of over 2 years.

Clinical outcomes after nonsurgical periodontal therapy with an Er:YAG laser device: a randomized controlled pilot study.

OBJECTIVE: The purpose of this study was to compare the short-term effects of nonsurgical periodontal treatment with the short-term effects of Er:YAG laser debridement (ERL) and manual scaling and root planning (SRP) in nonsmoking patients with chronic periodontitis. METHODS: Nineteen nonsmoking patients (mean age 60.7) with chronic generalized periodontitis were randomly treated with ERL or SRP in a split-mouth design. Clinical attachment level (CAL), periodontal pocket depth (PPD), and bleeding on probing (BOP) were recorded. Immediately after completion of the treatment procedure, patients used a visual analogue scale (VAS) to grade the degree of discomfort experienced during treatment. RESULTS: Both groups showed significant reductions in their PPD, CAL, and BOP values 2 months after treatment. The sites treated with Er:YAG laser demonstrated mean PPD changes that varied from 5.00 ± 0.63 to 3.54 ± 0.83 mm, mean CAL changes that varied from 5.19 ± 0.69 to 3.86 ± 0.94 mm, and BOP changes that varied from 26.57 ± 12.54 to 13.17 ± 7.52 mm. Sites treated with manual SRP demonstrated mean PPD changes that varied from 4.91 ± 0.55 to 3.51 ± 0.98 mm, mean CAL changes that varied from 5.08 ± 0.59 to 3.95 ± 1.16 mm, and BOP values that varied from 24.81 ± 7.65 to 15.41 ± 6.32 mm. Comparison of the two techniques demonstrated the statistically significant superiority of Er:YAG only for the CAL scores (p<0.05). CONCLUSIONS: Within the limits of this study, ERL may be posited as an alternative to mechanical treatment in the management of chronic periodontitis. In addition, ERL may be performed on patients who are sensitive to the use of injectable anesthetics. Future studies, with larger samples, are needed to determine the long-term clinical outcomes of ERL.

Tooth desensitization with an Er:YAG laser: in vitro microscopical observation and a case report.

Tooth hypersensitivity is a frequent condition that causes discomfort and sometimes severe pain. It is caused by exposure of spots of dentinal tubules to the oral environment. Conventional desensitizing agents (professional pastes, toothpastes, mouthwashes) aim to obliterate the exposed dentinal tubules. Laser desensitization was introduced as an alternative efficient tool for the immediate treatment of tooth hypersensitivity. We explored in vitro the microscopical occluding effects of the Er:YAG laser on exposed dentinal tubules. The clinical application of this technique is also described.

Bioactive materials in endodontics.

Endodontic treatment in dentistry is a delicate procedure and many treatment attempts fail. Despite constant development of new root canal filling techniques, the clinician is confronted with both a complex root canal system and the use of filling materials that are harmful for periapical tissues. This paper evaluates reported studies on biomaterials used in endodontics, including calcium hydroxide, mineral trioxide aggregate, calcium phosphate ceramics and calcium phosphate cements. Special emphasis is made on promising new biomaterials, such as injectable bone substitute and injectable calcium phosphate cements. These materials, which combine biocompatibility, bioactivity and rheological properties, could be good alternatives in endodontics as root canal fillers. They could also be used as drug-delivery vehicles (e.g., for antibiotics and growth factors) or as scaffolds in pulp tissue engineering.

[Stem cells of dental pulp]. / Les cellules souches de la pulpe dentaire.

Any clinician dreams to obtain the regeneration of the destroyed organ for his patient. In the human being, the regeneration of complex structures is not possible, except the liver and the bone marrow, which can be regenerated because of the presence of adult stem cells in these tissues. The stem cells have two principal properties: they ensure their self-renewal and they have the ability to differentiate into several cellular types. Using specific markers allowing the identification of the stem cells in bone marrow, stem cells were observed in dental pulp tissues. Although the origin, the identification, and the localization of these stem cells of dental pulp remain under consideration, the optimism in research on stem cells permits to believe that the knowledge on dental stem cells will lead to their use in therapeutics.

Microwave irradiation of ethanol-fixed bone improves preservation, reduces processing time, and allows both light and electron microscopy on the same sample.

Methylmethacrylate (MMA) embedding is routinely used for histomorphometry of undecalcified bone preserved by prolonged immersion in ethanol, a procedure that yields poor ultrastructural detail. Because microwave irradiation (MWI) facilitates penetration of fixatives, we have investigated whether it can improve preservation by ethanol. Rat tibiae, some labeled with tetracycline, and a human iliac crest biopsy were immersed in 70% ethanol and dehydrated, both under MWI, for a total processing time of approximately 7 hr. Controls were not irradiated, and all specimens were embedded in MMA at 4C. They were then processed for histomorphometry, histochemistry, structural analysis, and immunolabeling. The results showed that histological preservation was improved with MWI. Static bone formation and resorption parameters and rate of mineral apposition were similar to those of conventionally processed specimens. Mineral distribution, as visualized by von Kossa staining and backscattered electron imaging, was not affected. Alkaline phosphatase and tartrate-resistant acid phosphatase activity, as well as immunolocalization of bone sialoprotein and osteopontin, were readily visualized. Ultrastructurally, osteopontin exhibited a typical distribution in mineralization foci, between calcified collagen fibrils, and at cement lines. These data show that MWI improves preservation and permits application of a broad spectrum of analytical methodologies on the same bone sample while considerably reducing processing time.

Current state of the art of biphasic calcium phosphate bioceramics.

We have developed 15 years ago, with the collaboration of Lynch, Nery, and LeGeros in the USA, a bioactive concept based on biphasic calcium phosphate (BCP) ceramics. The concept is determined by an optimum balance of the more stable phase of HA and more soluble TCP. The material is soluble and gradually dissolves in the body, seeding new bone formation as it releases calcium and phosphate ions into the biological medium. The bioactive concept based on the dissolution/transformation processes of HA and TCP has been applied to both Bulk, Coating and Injectable Biomaterials. The events at the calcium phosphate (CaP) biomaterial/bone interface represent a dynamic process, including physico-chemical processes, crystal/proteins interactions, cells and tissue colonization, bone remodeling, finally contributing to the unique strength of such interfaces. An important literature and numerous techniques have been used for the evaluation of the fundamental physico chemical and biological performance of BCP concept. This type of artificial bone used from a long time in preclinical and in clinical trial, revealed the efficiency for bone filling, performance for bone reconstruction and efficacy for bone ingrowth at the expense of the micro macroporous BCP bioceramics.