In vitro evaluation of antimicrobial activity of sealers and pastes used in endodontics

The antimicrobial activity of four root canal sealers (AH Plus, Sealapex, Ketac Endo, and Fill Canal), two calcium hydroxide pastes (Calen and Calasept), and a zinc oxide paste was evaluated. Seven bacterial strains were used, six of them standard; Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 25922, and Enterococcus faecalis ATCC 10541. There was a wild strain of Streptococcus mutans isolated from saliva obtained in an adult dental clinic. Activity was evaluated using the agar diffusion method with Brain Heart Infusion agar and Müller Hinton medium seeded by pour plate. Calcium hydroxide-based sealers and pastes were either placed directly into 4.0 × 4.0 mm wells or by using absorbent paper points. The plates were kept at room temperature for 2 hr for diffusion. After incubation at 37°C for 24 hr, the medium was optimized with 0.05 g% TTC gel and inhibition haloes were measured. All bacterial strains were inhibited by all materials using the well method. However, when the materials were applied with absorbent paper points, Enterococcus faecalis was not inhibited by zinc oxide, and Pseudomonas aeruginosa was not inhibited by AH Plus, Fill Canal, and the zinc oxide-based paste. We conclude that sealers and pastes presented antimicrobial activity in vitro and culture medium optimization with 0.05 g% TTC gel facilitated observation of the inhibition haloes. Copyright © 2000 by The American Association of Endodontists.

Calcium hydroxide intracanal dressing removal with different rotary instruments and irrigating solutions: A scanning electron microscopy study

This study evaluated the efficacy of 2 types of rotary instruments employed in association with sodium hypochlorite (NaOCl) or EDTA in removing calcium hydroxide (CH) residues from root canals dentin walls. Forty-two mandibular human incisors were instrumented with the ProTaper System up to F2 instrument, irrigated with 2.5% NaOCl followed by 17% EDTA and filled with a CH intracanal dressing. After 7 days, the CH dressing was removed using 4 techniques: NiTi rotary instrument size 25, 0.06 taper (K3 Endo) and irrigation with 17% EDTA (Group 1), NiTi rotary F1 instrument (ProTaper) and irrigation with 17% EDTA (Group 2), NiTi rotary instrument size 25, 0.06 taper and irrigation with 2.5% NaOCl (Group 3) and NiTi rotary F1 instrument and irrigation with 2.5% NaOCl (Group 4). Two roots without intracanal dressing were used as negative controls. Teeth were evaluated by scanning electron microscopy, in the cervical and apical canal thirds. None of the techniques removed the CH dressing completely. In the apical and cervical thirds, F1 instrument was better than instrument size 25, 0.06 taper in removing CH residues (p<0.05), regardless of the final irrigating solution. No difference was found between the irrigating solutions in the groups of F1 instrument and of instrument size 25, 0.06 taper (p>0.05). The negative controls had no CH residues on the dentin walls. In conclusion, the ProTaper F1 instrument was better than K3 Endo instrument size 25, 0.06 taper in the removal of CH intracanal medication, regardless of irrigating solution used.

Influência do momento da obturação definitiva do canal radicular no reimplante dentário imediato

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tarsomere and distal tibial glands: structure and potential roles in termites (Isoptera: Rhinotermitidae, Termitidae)

Conselho Nacional de Desenvolvimento Científico e Tecnologico (CNPq)

Estudo in vivo e in vitro da incidência de bifurcação do canal radicular de incisivos inferiores pelo método radiográfico digital direto

Pós-graduação em Biopatologia Bucal - ICT

Image-Guided Cryoablation of the Spine in a Swine Model: Clinical, Radiological, and Pathological Findings with Light and Electron Microscopy

This study was designed to present the feasibility of an in vivo image-guided percutaneous cryoablation of the porcine vertebral body. Methods The institutional animal care committee approved this study. Cone-beam computed tomography (CBCT)-guided vertebral cryoablations (n = 22) were performed in eight pigs with short, 2-min, single or double-freezing protocols. Protective measures to nerves included dioxide carbon (CO2) epidural injections and spinal canal temperature monitoring. Clinical, radiological, and pathological data with light (n = 20) or transmission electron (n = 2) microscopic analyses were evaluated after 6 days of clinical follow-up and euthanasia. Results CBCT/fluoroscopic-guided transpedicular vertebral body cryoprobe positioning and CO2 epidural injection were successful in all procedures. No major complications were observed in seven animals (87.5 %, n = 8). A minor complication was observed in one pig (12.5 %, n = 1). Logistic regression model analysis showed the cryoprobe-spinal canal (Cp-Sc) distance as the most efficient parameter to categorize spinal canal temperatures lower than 19 °C (p<0.004), with a significant Pearson’s correlation test (p < 0.041) between the Cp-Sc distance and the lowest spinal canal temperatures. Ablation zones encompassed pedicles and the posterior wall of the vertebral bodies with an inflammatory rim, although no inflammatory infiltrate was depicted in the surrounding neural structures at light microscopy. Ultrastructural analyses evidenced myelin sheath disruption in some large nerve fibers, although neurological deficits were not observed. Conclusions CBCT-guided vertebral cryoablation of the porcine spine is feasible under a combination of a short freezing protocol and protective measures to the surrounding nerves. Ultrastructural analyses may be helpful assess the early modifications of the nerve fibers.

Influence of a Parafunctional Oral Habit on Root Fracture Development After Trauma to an Immature Tooth

Root fractures in immature teeth are rare because the resilience of the alveolar bone is more favorable to the occurrence of luxation. This article reports a case of traumatic injury in an immature permanent tooth that progressed to root fracture, having a parafunctional oral habit as the possible modifying factor of case evolution. A 12-year-old boy presented for treatment complaining of a defective restoration and mild pain on the maxillary right central incisor. The patient had a history of crown fracture in this tooth due to trauma 2 years before. The clinical examination showed healthy gingival tissues and no abnormal tooth mobility, whereas radiographic projections revealed healthy periradicular tissues, incomplete root formation, and no visible root fracture. As pulp necrosis was diagnosed, calcium hydroxide therapy was started for canal disinfection and subsequent obturation. However, after 4 weeks of treatment, a horizontal fracture line was observed radiographically in the root's middle third. The patient denied a new traumatic injury, but revealed the habit of chewing on a pencil. Refraining from the deleterious oral habit was strongly advised, and root canal filling with mineral trioxide aggregate was performed to treat the root fracture. After 4 years of follow-up, the tooth has normal function and no abnormal mobility. Images suggestive of remodeling at the apical end of the coronal segment and replacement resorption of the apical segment are seen radiographically. This case demonstrates the need of following cases of dental trauma and the possible influence of parafunctional oral habits as modifying factors of case progression.

Evaluation of 2 endodontic techniques used to treat human primary molars with furcation radiolucency area: A 48-month radiographic study

Objective: To evaluate 2 techniques for the treatment of human primary molars with necrotic Pulp and bifurcation bone loss by means of radiographic examination for 48 months. Method and Materials: Fifty-one mandibular primary molars were evaluated in children ranging from 4.5 to 6.5 years of age. The teeth with necrotic pulp and bifurcation bone loss were diagnosed by radiographic examination. The teeth were divided into 2 groups: group 1 (28 teeth)-pulpotomy technique using formocresol as a temporary dressing between sessions and coronal chamber obturation with zinc oxide-eugenol cement; and group 2 (23 teeth)-pulpectomy technique with calcium hydroxide paste as a temporary dressing between sessions and root canal obturation with a dense Calcium hydroxide paste. Standardized radiographs were taken immediately after the fillings were completed and after 12, 24, 36, and 48 months. The radiographs were digitized and analyzed with software that outlined and measured the bifurcation radiolucency. Results: Bifurcation radiolucency reduced significantly or repaired completely for both treatnients in the first 12 months. Minor radiographic reduction of the lesion was observed from 12 to 24 months, and no significant reduction of the remaining radioulcent area was observed from 24 to 48 months after treatment. Conclusion: The 2 endodontic techniques evaluated showed similar results. The main effect of treatment on the lesion repair was obtained in the first year after treatment.

MRT Letter: A Novel Tegumental Gland in Female Imagoes of the Neotropical Termite Cornitermes cumulans (Isoptera, Termitidae, Syntermitinae)

In general, the exocrine glands of social insects are structures involved in the chemical communication associated with social life. Here, we report the discovery of an unknown tegumental gland that is present in the female imagoes of Cornitermes cumulans and occurs next to the well-developed tergal glands that have previously been described. The tegumental glands release their secretion in the intersegmental membrane and are composed of bicellular units, a secretory cell and a canal cell, that are closely located to the epidermal cells in the inferior part of the eighth and ninth tergites. The ultrastructure of the glandular cells showed abundant smooth endoplasmic reticulum, suggesting that the secretion may be pheromonal, although its function is still unknown. These exocrine structures are facing the tergal glands, and we hypothesized that they act synergistically with the tergal glands to generate short-range attraction during tandem behavior. Microsc. Res. Tech. 73: 1005-1008, 2010. (C) 2010 Wiley-Liss, Inc.

Mandibular glands in reproductives of asian termite coptotermes gestroi (Isoptera: Rhinotermitidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of the anti-resorptive ability of an experimental acetazolamide paste for the treatment of late replanted teeth: A study in rats

When late replantation is performed, the root surface and root canal should be treated. Notwithstanding failures still occur, because of the high rates of root resorption, evidencing the need to search for substances that may inhibit root resorption. The acetazolamide is a known anti-resorptive agent, and its use as root canal dressing may increase the success rates in the treatment of root resorption. Therefore, this study evaluated the effect of an acetazolamide paste used as root canal dressing in late replanted teeth. The study was conducted on 24 maxillary right incisors of rats, which were avulsed and divided in two groups. In group I, the teeth were kept dry for 30min, had their root surfaces rubbed with a blade, and were treated with 2% sodium fluoride at pH 5.5 for 20min; the root canals were instrumented and filled with acetazolamide paste; and then the teeth were replanted. In group II, the treatment was similar to group I, except for the root canal dressing, with utilization of calcium hydroxide in group II. At 15 and 60days after replantation, the animals were killed and the specimens were processed in a histotechnical laboratory for microscopic and morphometric analysis. The results demonstrated the ability of both intracanal substances to limit root resorption, yet they were unable to completely inhibit the root resorption. Replacement resorption lacunae were present in greater proportion in group II, at 60days. It was concluded that the acetazolamide paste was effective to limit the root resorption, being more effective in limiting the replacement resorption compared with calcium hydroxide. © 2012 John Wiley & Sons A/S.

Assessment of restorative treatment of patients with amelogenesis imperfecta

Purpose: The purpose of this study was to assess restorative treatment outcomes in the mixed dentition of amelogenesis imperfecta (AI) patients and determine the postrehabilitation oral health status and satisfaction of the patients. Methods: Clinical and radiographic examinations were performed on eight AI patients, who had 74 restorations placed in permanent incisors and molars, to allow evaluation of the integrity of the restorations and periodontal status post-treatment. Subjects completed a survey regarding esthetics, function, and sensitivity. Results: Among the 74 restorations evaluated, seven were lost; of the remaining restorations, 31 were posterior, and 36 were anterior. Ten were rated clinically unacceptable. Teeth with stainless steel crowns had a moderate gingival index (mean=2.3) and plaque index (mean=2.0) scores. Widening of the periodontal ligament and pulp canal obliteration were common radiographic findings. Subject's recall of satisfaction regarding esthetics (P=.002) and sensitivity (brushing-P=.03; eating-P=.01) showed a statically significant difference before and after treatment. Conclusions: During mixed dentition, teeth with amelogenesis imperfecta may be restored with conventional treatment modalities. Direct restorations should be considered interim with multiple repairs anticipated. Post-treatment, gingival inflammation and plaque accumulation were observed. Subjects were satisfied with their appearance and reported a decrease of hypersensitivity. © 2013 Publishing Technology.

Avaliação da qualidade da obturação de canais radiculares e da confiabilidade do modelo de penetração de glicose

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reparo apical e periapical em dentes de cães pós tratamento endodôntico em função do curativo de demora e de um novo cimento obturador. Importância do curativo de demora e do cimento obturador na infiltração apical in vitro

Pós-graduação em Odontologia - FOAR

Análise histomorfológica de dentes decíduos de cães com rizogênese incompleta, após biopulpectomia e obturação dos canais radiculares com hidróxido de cálcio em diferentes veículos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)