Assessing bone formation on hydrophilic and hydrophobic implant surfaces in a murine model treated with bisphosphonates.

OBJECTIVE: To evaluate the osseointegration of implants with hydrophobic (HFB) and hydrophilic (HFL) surfaces in a murine model of high-dose bisphosphonates (BPs). MATERIALS AND METHODS: Sixty-four rats were randomly allocated into four groups: control group with HFB implants (CG-HFB), control group with HFL implants (CG-HFL), BP group with HFB implants (BP-HFB), and BP group with HFL implants (BP-HFL). Animals were euthanized after 15 and 45 days (n=8). The dependent variables assessed were the removal torque (biomechanical analysis), the bone volume around the implants (%BV/TV) (microtomographic analysis), the bone-implant contact (%BIC), the bone between the threads (%BBT) (histomorphometric analysis), and the expression of bone metabolism markers (immunohistochemistry analysis). RESULTS: The CG-HFL and BP-HFL groups presented higher removal torque than the CG-HFB and BP-HFB implants. The %BIC of the CG-HFL surfaces was slightly higher than that of the CG-HFB implants. The BP-HFB and BP-HFL groups presented a higher %BIC than that of the CG-HFB and CG-HFL groups (p<0.001). BP therapy also increased the %BBT at both implant surfaces. Higher levels of ALP were observed in the matrix region of bone tissue on the HFL surfaces than on the HFB surfaces. CONCLUSION: Both surfaces enable osseointegration in rats under BP therapy. CLINICAL RELEVANCE: The study demonstrates that hydrophobic (HFB) and hydrophilic (HFL) implant surfaces can promote osseointegration in rats undergoing bisphosphonate therapy. The HFL surfaces exhibited improved biomechanical performance, higher bone-implant contact, and increased bone volume, suggesting their potential clinical relevance for implant success in individuals on bisphosphonate treatment.

Influence of obesity on osseointegration of implants with different surface treatments: A preclinical study.

OBJECTIVE: The aim of the present study was to evaluate the effect of obesity on the osseointegration of implants with hydrophobic and hydrophilic surfaces. MATERIALS AND METHODS: Sixty-four male rats were distributed among four experimental groups: H-HB (Healthy/Hydrophobic): healthy animals with hydrophobic implants; H-HL (Healthy/Hydrophilic): healthy animals with hydrophilic implants; O-HB (Obese/Hydrophobic): animals with induced obesity and hydrophobic implants; O-HL (Obese/Hydrophilic): animals with induced obesity and hydrophilic implants. One hundred and twenty-eight implants were installed in the tibiae of the animals bilaterally (64 on the left tibiae and 64 on the right one) after 75 days of a specific diet (standard or high-fat diet) and euthanasia was performed in the experimental periods of 15 and 45 days after implant placement. Bone formation was assessed by biomechanical analysis (on the left tibiae of each animal), and microtomographic and histomorphometric analyses (on the right tibiae of each animal). Statistical analysis was performed using the Shapiro-Wilk test for normality and ANOVA followed by Tukey test to observe whether there was a significant difference between groups (p < 0.05); the t-test was used to compare the animals' body weight. RESULTS: The biomechanical analysis showed an increase in the removal torque value of animals after 45 days in comparison to after 15 days, with the exception of O-HB groups. The microtomographic analysis demonstrated no significant differences in the mineralized bone tissue volume between the groups. In the histomorphometric analysis, the H-HL/45 day group/period demonstrated higher bone-implant contact, in comparison to H-HL/15 days and the O-HL/45 day group/period showed an increase in bone area between the implant threads, in comparison to O-HL/15 days. CONCLUSION: In conclusion, obesity does not interfere with the osseointegration of hydrophobic and hydrophilic implants.

Comparação de diferentes metodologias para análise histométrica de implantes: estudo em ratos / Comparison of different methodologies for histometric analysis of implant. Study in rat

Introdução: Diferentes metodologias tem sido utilizadas para avaliação histológica da osseointegração, levando a diferentes resultados. Objetivo: O objetivo é comparar diferentes metodologias de análise histomorfométrica da osseointegração de implantes com diferentes superfícies, instalados em tíbias de ratos. Material e método: 24 ratos foram aleatoriamente divididos em 3 grupos (n = 8) para a instalação dos implantes. Esses grupos foram divididos de acordo com o tipo de implante instalado na tíbia: Grupo Hidrofílico - HFL (instalação de implante com superfície modificada por jateamento de óxidos e ataque ácido e mantida em solução de cloreto de sódio), Grupo Hidrofóbico - HFB (instalação de implante com superfície modificada por jateamento de óxidos e ataque ácido) e Grupo Usinado - U (instalação de implante com superfície usinada). No período de 45 dias após os procedimentos cirúrgicos de instalação dos implantes, os animais foram submetidos à eutanásia, e as tíbias foram removidas, sendo realizado o processamento histológico para amostras não descalcificadas. Após a obtenção das lâminas, foi realizada a análise histomorfométrica para avaliar as porcentagens de contato osso-implante (% BIC) e da área óssea entre as espiras (% BBT). As mensurações foram realizadas em duas diferentes regiões: 1) as roscas do implante na região do osso cortical e 2) todas as roscas do implante inseridas no osso (cortical e medular). A análise estatística foi feita por meio de ANOVA One-Way, seguida pelo teste de Tukey para análise inferencial dos dados. Resultado: Quando o BIC e o BBT foram analisados de forma independente nas regiões cortical e trabecular/total, observou-se uma diferença no comportamento histológico dos implantes de acordo com o tratamento de superfície. Os implantes HFL apresentaram BIC (%) trabecular 16,85% maior (p = 0,02) do que os implantes HFB e 26,12% maior (p ≤ 0,0001) do que os implantes usinados. Contudo, a região cortical de todos os grupos apresentou valores de BIC cortical significativamente maiores ao redor dos implantes, independentemente da superfície. Conclusão: Os resultados obtidos demonstraram que a formação óssea peri-implantar foi superior nas análises realizadas apenas em osso cortical, se comparados aos valores obtidos na mensuração total (osso cortical somado ao medular). Também foi possível observar que, dentro da mesma superfície, os valores de BIC (%) foram superiores em osso cortical. Em relação às limitações do estudo, pode-se concluir que diferentes metodologias de análise histométrica da osseointegração ao redor de diferentes superfícies de implantes instalados em tíbias de ratos podem interferir nos resultados de osseointegração, independentemente da superfície analisada.

Introduction: Different methodologies were used for histological evaluation of osseointegration, leading to different results. Objective: The objective is to compare different methodologies for histomorphometric analysis of the osseointegration of implants with different surfaces, installed in rat tibias. Material and method: Twenty-four rats were randomly divided into 3 groups (n=8) for implant installation. These groups were divided according to the type of implant that will be installed in the tibia: Hydrophilic Group (installation of an implant with a surface modified by oxide blasting and acid attack and maintained in a sodium chloride solution), Hydrophobic Group (installation of an implant with surface modified by oxide blasting and acid attack) and Machined Group (implant installation with machined surface). Within 45 days after the surgical procedures to install the implants, the animals were euthanized and the tibias were removed, and histological processing was carried out for non-decalcified samples. After obtaining the slides, histomorphometric analysis was performed to evaluate the percentages of bone-implant contact (%BIC) and the bone area between the turns (%BBT). Measurements were carried out in two different regions: 1) the implant threads in the cortical bone region and 2) all implant threads inserted into the bone (cortical and medullary). Statistical analysis was performed using One-Way ANOVA followed by Tukey's test for inferential data analysis. Result: The BIC and BBT were analyzed independently in the cortical and trabecular/total regions, a difference was observed in the histological behavior of the implants according to the surface treatment. HFL implants showed trabecular BIC (%) 16.85% higher (p=0.02) than HFB implants and 26.12% higher (p≤0.0001) than machined implants. However, the cortical region of all groups showed significantly higher cortical BIC values around the implants, regardless of the surface. Conclusion: the results obtained demonstrated that peri-implant bone formation was superior in analyzes carried out only on cortical bone, compared to the values obtained in the total measurement (cortical bone plus medullary bone). It was also possible to observe that, even within the same surface, the BIC(%) values were higher in cortical bone. Within the limitations of the study, it can be concluded that different methodologies for histometric analysis of osseointegration around different surfaces of implants installed in rat tibias can interfere with the results of osseointegration regardless of the surface analyzed

Photodynamic inactivation using a chlorin-based photosensitizer with blue or red-light irradiation against single-species biofilms related to periodontitis.

Chlorin-e6 (Ce6), as a photosensitizer (PS), has demonstrated significant reduction of microorganisms' viability when irradiated by red light. However, the main absorption peak of this PS is located at blue light spectrum, which is less investigated. This study aimed to evaluate the effect of pure-chlorin-e6-mediated photodynamic inactivation (PDI) using different light sources (450 or 660 nm) against biofilms related to periodontitis. Streptococcus oralis, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans single-species biofilms were developed under proper conditions for five days. PDI was performed using different concentrations of Ce6 (100 and 200 mM), wavelengths (450 and 660 nm) and comparisons were made after colony forming unit and confocal laser scanning microscopy (CLSM) analysis. The use of light and PS were also individually tested. The greatest bacterial elimination was observed in the group where PDI was employed with blue light and concentration of 200 mM for all bacterial strains tested (4.01 log10 for A. actinomycetemcomitans, and total elimination for P. gingivalis and S. oralis), except for F. nucleatum, where 3.46 log10 reduction was observed when red light and 200 mM Ce6 were applied (p < 0.05). The antimicrobial effects of PDI mediated by Ce6 for all single pathogenic biofilms were confirmed by live/dead staining under CLSM analysis. For all single-species biofilms, the use of PDI mediated by chlorin-e6 photosensitizer under blue or red-light irradiation (450 and 660 nm) demonstrated a significant reduction in bacterial viability, but blue light showed a promising higher photobiological effect, encouraging its adjuvant use to basic periodontitis treatment.

Nueva Clasificación sobre las Enfermedades y Condiciones Periodontalesy Peri-implantares: Una Breve Reseña / Nova Classificação da Condições e Doenças Periodontais e Peri-implantares: Uma Breve Revisão / New Classification of Periodontal and Peri-Implant Diseases and Conditions: A Brief Review

En junio de 2018 se propuso una nueva clasificación de enfermedades y condiciones periodontales y peri-im-plantares, en una reunión realizada conjuntamente por la Academia Americana de Periodoncia y la Federación Europea de Periodoncia, con el objetivo de actualizar la clasificación de 1999 en uso durante los últimos 19 años. El objetivo del artículo es introducir esta nueva clasificación para que tanto clínicos e investigadores pue-dan aplicarla. La nueva clasificación incorporará nuevos conceptos a medida que se reporten nuevos resultados sobre estudios que sean realizados en el futuro.

A new classification of periodontal and peri-implant diseases and conditions was proposed in June 2018, in a meeting jointly held by the American Academy of Periodontology and European Federation of Periodontology, with the aim to update the 1999 classification in use for 19 years. The article aimed at introducing the most re-cent periodontal and peri-implant classification to clinicians and scientific investigators. The new classification has an in-built plan for periodic revisions while upcoming studies are carried out.

Uma nova classificação das condições e doenças periodontais e peri-implantares foi proposta em junho de 2018, em um encontro que reuniu a Academia Americana de Periodontia e a Federação Europeia de Periodontia, que teve como objetivo atualizar a classificação de 1999, amplamente utilizada nos últimos 19 anos. Este artigo tem como objetivo introduzir a mais nova classificação periodontal e peri-implantar aos clínicos e pesquisadores. A nova classificação possui um planejamento para revisões periódicas a medida que novos estudos são realizados.