Evaluation of the marginal fit at implant–abutment interface by optical coherence tomography

Abstract

Abstract. Vertical misfit of implant-abutment interface can affect the success of implant treatment; however, currently available modalities have limitations to detect these gaps. This study aimed to evaluate implant-abutment gaps in vitro using optical coherence tomography (OCT). Vertical misfit gaps sized 50, 100, 150, or 200 μm were created between external hexagonal implants and titanium abutments (Nobel Biocare, Göteborg, Sweden). A porcine gingival tissue slice, 0.5, 1.0, 1.5, or 2.0 mm in thickness, was placed on each implant-abutment interface. The gaps were evaluated by swept-source OCT at a center wavelength of 1330 nm (Panasonic Healthcare, Ehime, Japan) with beam angles of 90, 75 and 60 deg to the implant long-axis. The results suggested that while the measurements were precise, gap size and gingival thickness affected the sensitivity of detection. Gaps sized 100 μm and above could be detected with good accuracy under 0.5-or 1.0-mm-thick gingiva (GN). Around 70% of gaps sized 150 μm and above could be detected under 1.5-mm-thick GN. On the other hand, 80% of gaps under 2.0-mm-thick GN were not detected due to attenuation of near-infrared light through the soft tissue. OCT appeared as an effective tool for evaluating the misfit of implant-abutment under thin layers of soft tissue. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Observation and determination of periodontal tissue profile using optical coherence tomography

“…Refractive index and attenuation co e fficient (product of absorption/scattering) are both important for OCT measurement. The attenuation coefficient affects the image quality of OCT, ie, contrast of image and maximal imaging (penetration) depth, whereas the refractive index of tissue affects the thickness measurements by OCT. To ensure the validity of refractive index measurement of human gingiva, the refractive indices of purified water and porcine gingiva, which were already known, were determined in advance. The refractive index of purified water and porcine gingiva was determined as 1.335 and 1.393, respectively.…”

“…The refractive index of purified water and porcine gingiva was determined as 1.335 and 1.393, respectively. The values previously reported for the refractive indices at 1310 nm wavelength were 1.320 for purified water and 1.396 for porcine gingiva . These values confirmed the accuracy and validity of the current method when applied during the observation of oral mucosa.…”

“…There was a significant difference between lateral incisor and canine in alveolar mucosa. 20 and porcine gingiva, 21 which were already known, were determined in advance. The refractive index of purified water and porcine gingiva was determined as 1.335 and 1.393, respectively.…”

“…In the present study, the refractive indices of purified water and porcine gingiva, which have been reported previously, were determined to ensure the validity of the OPL method before applying it to human gingival tissues. The OPL matching method reported by Hariri et al was used for calculation of the refractive index.…”

Métodos de exames por imagem utilizados no diagnóstico de desadaptação entre implante e componente protético: uma revisão de literatura

“…8 É importante salientar que todos os estudos analisados realizaram pesquisas em condições laboratoriais, não tendo, portanto, as limitações clínicas dadas pelas condições anatômicas variadas de cada paciente, as quais tornam a obtenção de radiografias ortogonais ainda mais crítica. Portanto, fica o alerta para que se busquem ferramentas que possibilitem tornar a técnica mais próxima da posição ortogonal, tal como o posicionador PIXRL desenvolvido por Lin et al 26 Dentre outros métodos de exame por imagem, a OCT (Tomografia por Coerência Óptica), estudada por Kikuchi et al, 27 promete ser precisa na detecção dessas desadaptações. Entretanto, até o momento, esse método tem sua aplicação limitada a regiões onde a espessura de mucosa não seja superior a 1 mm para a obtenção de um diagnóstico preciso.…”