Alveolar bony crest preservation at implants installed immediately after tooth extraction: An experimental study in the dog

Aim: To evaluate the influence of deproteinized bovine bone mineral in conjunction with a collagen membrane, at implants installed into sockets in a lingual position immediately after tooth extraction, and presenting initial horizontal residual buccal defects <2 mm. Material and methods: The pulp tissue of the mesial roots of 4P4 was removed in six Labrador dogs, and the root canals were filled with gutta-percha and cement. Flaps were elevated, and the buccal and lingual alveolar bony plates were exposed. The premolars were hemi-sectioned, and the distal roots were removed. Implants were installed in a lingual position and with the margin flush with the buccal bony crest. After installation, defects resulted at about 1.7 mm in width at the buccal aspects, both at the test and control sites. Only in the left site (test), deproteinized bovine bone mineral (DBBM) particles were placed into the defect concomitantly with the placement of a collagen membrane. A non-submerged healing was allowed. Results: After 3 months of healing, one implant was found not integrated and was excluded from the analysis together with the contralateral control implant. All remaining implants were integrated into mature bone. The bony crest was located at the same level of the implant shoulder, both at the test and control sites. At the buccal aspect, the most coronal bone-to-implant contact was located at a similar distance from the implant margin at the test (1.7 ± 1.0 mm) and control (1.6 ± 0.8 mm) sites, respectively. Only small residual DBBM particles were found at the test sites. Conclusion: The placement of an implant in a lingual position into a socket immediately after tooth extraction may favor a low exposure of the buccal implant surface. The use of DBBM particles, concomitantly with a collagen membrane, did not additionally improve the outcome obtained at the control sites. © 2011 John Wiley & Sons A/S.

Comparative analysis of Enterococcus faecalis biofilm formation on different substrates

Introduction: The aim of this study was to compare Enterococcus faecalis biofilm formation on different substrates. Methods: Cell culture plates containing growth medium and E. faecalis (ATCC 29212) were used to grow biofilm on bovine dentin, gutta-percha, hydroxyapatite, or bovine bone. Substrates were incubated at 37°C for 14 or 21 days, and the medium was changed every 48 hours. After the growth induction periods, specimens (n = 5 per group and per induction period) were stained by using Live/Dead, and the images were analyzed under a confocal microscope. The total biovolume (μm3), live bacteria biovolume (μm3), and substrate coverage (%) were quantified by using the BioImage-L software. Results obtained were analyzed by nonparametric tests (P =.05). Results: Biofilm formation was observed in all groups. Gutta-percha had the lowest total biovolume at 14 days (P <.05) and hydroxyapatite the highest at 21 days (P <.05). No significant difference was observed in green biovolume at 14 days. At 21 days, however, hydroxyapatite had the highest volume (P <.05). The percentages of coverage were similar among all substrates at 21 days (P >.05), but at 14 days, bovine bone presented the highest coverage (P <.05). Conclusions: E. faecalis was capable of forming biofilm on all substrates during both growth periods; hydroxyapatite presented the highest rates of biofilm formation. The type of substrate influenced the biofilm characteristics, according to the parameters evaluated. © 2013 American Association of Endodontists.

Ridge preservation at implants installed immediately after molar extraction. An experimental study in the dog

Aim: To evaluate the influence of deproteinized bovine bone mineral (DBBM), in conjunction with a collagen membrane, on bone resorption at implants installed in a lingual position immediately into extraction sockets with horizontal residual buccal defects >2.0 mm. Material & methods: The pulp tissue of the mesial roots of 1M1 was removed in six Labrador dogs, and the root canals were filled with gutta-percha and cement. Flaps were elevated. The molars were hemi-sectioned and the distal roots removed. Implants were installed in a lingual position and with the shoulder flush with the buccal bony crest. After installation, defects of about 2.5 and 2.7 mm in width resulted at the buccal aspects of the test and control sites, respectively. Only in the left site (test), deproteinized bovine bone mineral (DBBM) particles were placed into the defect concomitantly with the placement of a collagen membrane. On the control sites, no biomaterials were applied. A non-submerged healing was allowed. Results: After 3 months of healing, one control implant was not integrated and was excluded from the analysis, together with the contralateral test implant. All remaining implants were integrated into mature bone. The buccal alveolar bony crest was resorbed more at the test compared with the control sites, 2.2 ± 0.9 mm and 1.5 ± 1.3 mm, respectively. The vertical resorption of the lingual plate was 1.6 ± 1.5 mm and 1.5 ± 1.1 mm at the test and control sites, respectively. Only small residual DBBM particles were found at the test sites (1.4%). Conclusion: The use of DBBM particles to fill buccal defects of ≥2.5 mm at implants installed immediately into alveolar extraction sockets did not preserve the buccal bony wall. © 2012 John Wiley & Sons A/S.

Sealing ability of MTA used as a root end filling material: Effect of the sonic and ultrasonic condensation

Despite the excellent properties of mineral trioxide aggregate (MTA), the condensation technique may have some influence in its sealing ability. The purpose of this study was to compare the sealing ability of sonic and ultrasonic setting of MTA. Thirty-four extracted human teeth had their canals prepared and filled with Sealapex sealer and gutta-percha using the active lateral condensation technique. The teeth were rendered waterproof and apicoectomy performed at 3 mm from the apex. Root-end cavities (3.0 mm deep and 1.4 mm diameter) were prepared with diamond ultrasonic tips. The root-end cavities were filled with Pro-Root MTA® with ultrasonic vibration, sonic vibration or no vibration. The positive control group did not receive any material while the negative control group was totally rendered waterproof. After material set, the specimens were immersed in Rodhamine B for 24 h, under vacuum in the first 15 min, then washed, dried and split longitudinally for evaluating the infiltration at the dentin/material interface. Data were analyzed using ANOVA and Tukey's tests at 5% significance level. Sonic vibration promoted the lowest infiltration values (p<0.05). It was concluded that sonic vibration could be considered an efficient aid to improve the sealing ability of MTA when used as root-end filling material.

Effect of MTA-based sealer on the healing of periapical lesions

Some manufacturers have recently added specific components to improve the ease of handling and insertion material properties of MTA in order to create MTA-based sealers. Objective: The aim of this study was to evaluate the healing of periapical lesions in canine teeth after a single session of endodontic treatment with MTA Fillapex® compared with Sealapex® or Endo-CPM-Sealer®. Material and Methods: Sixty-two root canals were performed on two 1-year-old male dogs. After coronal access and pulp extirpation, the canals were exposed to the oral cavity for 6 months in order to induce periapical lesions. The root canals were prepared, irrigated with a solution of 2.5% sodium hypochlorite and filled with gutta-percha and different sealers, according to the following groups: 1) Sealapex®; 2) Endo-CPM-Sealer®; and 3) MTA Fillapex®. Some teeth with periapical lesions were left untreated for use as positive controls. Healthy teeth were used as negative controls. After 6 months, the animals were sacrificed and serial sections from the roots were prepared for histomorphologic analysis and stained with hematoxylin and eosin and the Brown and Brenn technique. The lesions were scored according to pre-established histomorphologic parameters and the scores statistically analyzed using the Kruskal-Wallis test. Results: All 3 materials produced similar patterns of healing (p>0.05); in particular, persistent inflammation and absence of complete periapical tissue healing were consistently noted. Conclusions: Preparation of the infected root canals followed by filling with the materials studied was insufficient to provide complete healing of the periapical tissues.

Avaliação da biocompatibilidade da seiva do Croton lechleri (sangue de dragão) em tecido subcutâneo de ratos

Pós-graduação em Odontologia - FOA

Comparação entre a capacidade de desobturação de canais radiculares obturados com cimentos à base de MTA, polímero da mamona e resina epóxica utilizando instrumento manual ou rotatório

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação microscópica da adaptação de diferentes materiais obturadores às paredes do canal radicular

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do pH, da liberação de íons cálcio e da capacidade seladora de cimentos contendo hidróxido de cálcio e MTA utilizados em obturação retrógrada

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Material obturador de canal radicular à base de uretano metacrilato: estudo histológico e da infiltração coronária em dentes de cães

Pós-graduação em Odontologia - FOAR

Avaliação da infiltração apical, pós tratamento de canais radiculares, utilizando 4 diferentes técnicas combinadas de instrumentação rotatória e obturação por termoplastificação. Estudo in vitro

Pós-graduação em Odontologia - FOAR

Análise, por MEV, da efetividade de soluções irrigadoras e substâncias químicas auxiliares na limpeza de canais radiculares e estudo complementar da interferência desta limpeza na penetração do cimento obturador nos túbulos dentinários

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Infiltração bacteriana em obturações realizadas com diferentes cimentos endodônticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise histológica, histomicrobiológica e radiológica de dentes de cães com necrose pulpar, induzida experimentalmente, submetidos a diferentes materiais dentários

Pós-graduação em Cirurgia Veterinária - FCAV

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)