In vivo and in vitro analysis in a rat model using zoledronate and alendronate medication: microbiological and scanning electron microscopy findings on peri-implant rat tissue

Background The aim of the present study was to assess the development of bacterial deposits and morphological parameters around dental zirconia and titanium implants compared with natural teeth during systemic bisphosphonate medication. Materials and methods Fifty-four rats were randomly allocated into one control group and two experimental groups (drug application of zoledronic and alendronic acid), with 18 animals in each group. After 4 weeks of drug delivery, either a zirconia or a titanium implant was immediately inserted. Microbiological analysis conducted 1 week, 8 weeks, and 12 weeks after surgery included total bacterial count and composition measurements. Samples were analyzed in a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX). Bone cell morphology was analyzed by transmission electron microscopy (TEM). Results One week after surgery, titanium and zirconia implants of the alendronic acid and control group showed a significantly higher bacterial count when compared to natural teeth in rats with zoledronic acid administration (p < 0.01). Less significant differences were recorded after 3 months, at which time no inter-material differences were evaluated (p > 0.05). I n the control group, TEM analysis showed that the osteoblasts had a strongly developed endoplasmic reticulum. In contrast, the endoplasmic reticulum of the osteoblasts in drug-treated animals was significantly less developed, indicating less activity. Conclusions Within the limits of this study, neither implant material was superior to the other at 3-month follow-up. With regard to the treatment and complications of patients with bisphosphonates, the implant material should not be an influencing factor. Bisphosphonates can be used in the rat model to reduce not only the activity of osteoclasts but also osteoblasts of the peri-implant bone.

Antibacterial activity, bio-compatibility and osteogenic differentiation of graphene oxide coating on 3D-network poly-ether-ether-ketone for orthopaedic implants

Poly-ether-ether-ketone (PEEK) has attracted increasing attention as a promising orthopaedic implant material owing to its excellent mechanical properties and biocompatibility. However, its antibacterial properties must be improved as an implant material. In this study, PEEK was sulfonated to obtain a porous surface, and graphene oxide (GO) was deposited to form a coating with antibacterial activity and biocompatibility. After PEEK was sulfonated for different durations, GO was deposited on the surface to prepare the coating (SPEEK-GO), which was then characterised using scanning electron microscopy (SEM), Raman spectroscopy, and contact angle measurements. The in vitro study included antimicrobial and cellular tests. The results showed that the PEEK sulfonated using a 10-min treatment exhibited a uniform porous structure and provided a better basal surface for the deposition of GO. The SPEEK-GO coating displayed strong antibacterial activity against two common dental pathogens. It exhibited good adhesion and proliferation of MC3T3-E1. Moreover, it showed osteogenic differentiation as bone implant material.

Bone Response in vivo of Ti-45Zr Alloy as Dental Implant Material

The full text of this preprint has been withdrawn by the authors due to author disagreement with the posting of the preprint. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

An Analytical Study of the Factors Affecting Hearing Improvement after Ossiculoplasty – A Retrospective Study, Mathura, Uttar Pradesh

BACKGROUND Otologists always yearn to improve the hearing outcome of their patients with chronic suppurative otitis media. There are different options for ossiculoplasty to choose from, depending on the extent of disease, condition of ossicular chain and availability of implant material and there has always been a quest to make appropriate decision with a predictable outcome. In this study, we have tried to analyse various factors which can affect hearing outcome after Ossiculoplasty. METHODS A retrospective study was done to study the effect of implant material, condition of ossicular chain and disease in the mastoid on post-operative hearing improvement on 200 patients, who underwent tympanoplasty or tympanomastoidectomy from January 2018 to January 2020, in Department of Otorhinolaryngology and Head and Neck Surgery, K.D. Medical College, Mathura. Decision of ossiculoplasty was made based on intra-operative findings. Autograft incus, Teflon TORP (total ossicular replacement prosthesis) and cartilage columella were used based on availability and feasibility. RESULTS Mean improvement in average air-bone gap of 200 patients was found to be 18.57 dB, with autograft incus, it was 19.99 dB, with Teflon TORP (total ossicular replacement prosthesis), 19.53 dB and with cartilage columella 16.73 dB (P = 0.023). Mean hearing improvement was 18.98 dB when handle of malleus was present and 15.59 dB when it was absent (P = 0.023). Mean hearing improvement was 19.42 dB when stapes superstructure was present and 16.92 dB when it was absent (P = 0.016). Even though the hearing outcome was better when mastoid was disease free (19.57 dB) compared to when it was diseased (18.30 dB), the difference was not statistically significant. (P = 0.177) CONCLUSIONS In our study, we found autograft incus to be the best material for ossiculoplasty and presence of handle of malleus and stapes superstructure improved postoperative hearing outcome significantly but involvement of mastoid by disease did not significantly affect the hearing outcome post-operatively. KEYWORDS Chronic Suppurative Otitis Media, Ossiculoplasty, Tympanoplasty, Ossicular Prosthesis, Autograft