Vinícius Ferreira

Guided bone regeneration using nonexpanded polytetrafluoroethylene membranes in preparation for dental implant placements--a report of 420 cases.

The biologic principle of guided bone regeneration has been successfully used to prevent bone loss in extraction sites. This study comprises 420 cases of alveolar ridge maintenance in preparation for dental implant placements. Nonexpanded polytetrafluoroethylene membranes were positioned over all extraction sites and left intentionally exposed. Lyophilized mineralized bone allografts were used to prevent membrane collapse when buccal bone walls were lost. Membranes were removed at week 4. At the time of implant placements, all sites presented soft tissue compatibility with keratinized gingiva. The mucogingival junction position seemed to be preserved. Exposed nonexpanded polytetrafluoroethylene membranes associated, or not, with bone graft provide tissue formation suitable for implant placement.

Comparative study of the polyvinyl siloxane technique with resin-splinted transfer copings used for multiple implant abutment impressions.

Statements of Problem: The lack of passivity in implant dentistry may result in failures. Therefore, impression is the first procedure in the fabrication of a passive prosthesis. The aim of this study is to compare the polyvinyl siloxane technique with a resin-splinted transfer copings used for multiple implant abutment impression. Methods: A master cast was obtained from an edentate ridge. From the master cast, 30 casts were obtained using 3 different impression techniques. Control technique was made with polyvinyl siloxane. Resin-splinted transfer copings in condensation siloxane or irreversible hydrocolloid were used as test. The distances between analogs were obtained using a profile projector. Statistical analysis was carried out using 1-way analysis of variance. Results: No significant difference among the 3 impression techniques (P > 0.05) was observed. Conclusion: Resin-splinted transfer copings in condensation siloxane or irreversible hydrocolloid produced impressions as accurately as polyvinyl siloxane.

Evaluation of a dense polytetrafluoroethylene membrane to increase keratinized tissue: a randomized controlled clinical trial.

Background:The presence of an adequate zone of keratinized tissue has been associated with implant health. This study evaluated the increasing of the zone of keratinized tissue using dense polytetrafluoroethylene (d-PTFE) membranes over extraction sites, without primary closure. Materials and Methods:Fifteen sites received d-PTFE membranes. The control sites received no membranes. All cases were sutured with no attempt to achieve primary closure. Before surgery, initial measurements of buccal and lingual keratinized tissue were taken from the mucogingival line (MGL) to the most coronal gingival margins. Final measurements were taken from the buccal MGL to the lingual MGL, 60 and 90 days after extractions. Results:In the test group, a mean increase in the zone of keratinized tissue of 7.06 ± 2.63 mm and 6.6 ± 2.84 mm was observed in 60 and 90 days, respectively. In the control group, a mean increase of 2.46 ± 1.59 mm and 1.40 ± 1.40 mm was observed in 60 and 90 days, respectively. Conclusion:Nonexpanded d-PTFE membranes can predictably be used to increase the zone of keratinized tissue in preparation to implant placement.

Multiple abutment positional guide.

Custom-made abutments are popular to correct malpositioned implants, enhance esthetics, and improve function. The implant abutment can be positioned in 6 or 12 different positions depending on the connection design. In addition, the number of positions increases exponentially when >1 abutment is to be placed. This report presents the fabrication and use of a multiple abutment positional guide. This device reduces the chair time for construction of implant-supported prostheses by seating the abutments within their correct locations.

Evaluation of the zone of keratinized tissue using exposed acellular dermal matrix over tooth extraction sites: a randomized controlled clinical trial.

Background:The presence of an adequate zone of keratinized tissue has been associated with implant health. This study evaluated the zone of keratinized tissue using exposed acellular dermal matrix (ADM) over extraction sites. Material and Methods:Fifteen sites received ADM, and fifteen control sites received no biomaterial. All sites were sutured with no attempt to achieve primary closure. Initial measurements of buccal and lingual keratinized tissue were taken from the mucogingival line (MGL) to the most coronal gingival margins. Final measurements were taken from the buccal MGL to the lingual MGL 90 days after surgery. Gingival biopsies were taken before implant placement. Results:Test and control groups exhibited a mean value of 4.40 ± 1.45 mm and 1.40 ± 1.40 mm, respectively. The newly formed tissue revealed similar histological aspect of normal keratinized tissue. Conclusion:Exposed ADM used over tooth extraction sockets can predictably be used to increase the zone of keratinized tissue.

Rugosidade Superficial de uma Cerâmica Glazeada e Submetida a Diferentes Sistemas de Polimento

Resumen pt: Objetivo: Comparar a rugosidade de superficie da porcelana glazeada com a obtida a partir de diferentes sistemas de acabamento e polimento, apos simulaca...

Análise da passagem de luz visível através do cerômero e porcelana

Resumen pt: Objetivo: Analisar a quantidade de energia luminosa que chega ao material cimentante durante a polimerizacao de uma peca protetica. Metodologia: Foram co...

Distância da crista alveolar ao canal mandibular medida em 100 mandíbulas secas

O conhecimento anatomico da mandibula, incluindo as possiveis variacoes, se tornou imprescindivel com a crescente demanda pela instalacao de implantes osseointegraveis para reabilitacao oral. Por isso a importância de se conhecer o melhor possivel a localizacao do canal mandibular, principalmente em regiao posterior de mandibula, se faz necessario. O objetivo do presente trabalho e estudar a altura entre a cortical superior do canal mandibular e a crista ossea alveolar (ACC) em mandibulas dentadas, por meio de morfometria manual com paquimetro digital. Cem mandibulas secas de cadaveres humanos brasileiros adultos, todos masculinos, sem distincao de raca, foram seccionadas proximo a linha media e tiveram a ACC medida na regiao de primeiro e segundo molares. A media encontrada ficou entre 15 e 17 mm. The anatomic knowledge of the mandible, including its possible variations, has become essential sincethe demand for osteointegrated implants for oral rehabilitationincreased. That is the reason of the importance of knowing the best the location of the mandibles canal, mainly in its posterior region. The aim of this work is to study the distance between the superior cortical of the mandibles canal and the alveolar crest in dentatemandibles, by manual morphometry, using a digital paquimeter. One hundred dry jaws of humans brazilian adult cadavers, all males, with no distinction of race, were sectioned close to the midline and were measured in the first and second molars area. The average was found between 15 to 17 mm.