Comparative Analysis of Surface Modification Techniques for Assessing Oral Implant Osseointegration: An Animal Study.

BACKGROUND: Effective implant placement depends critically on the implant's level of osseointegration with the alveolar bone. To increase osseointegration during implant placement, research has concentrated on the surface modification of implants, and morphological analyses have looked at the thread pattern in close interaction with the bone's surface. AIM: This study aimed to assess and compare the extent of oral implant osseointegration in different surface modification techniques. MATERIALS AND METHODS: In this study, 12 healthy adult dogs aged 18-24 months were used. Tooth extractions were performed on both sides of the mandible, and wounds were closed with sutures. Two months later, the right mandible of each dog underwent local anesthesia and general anesthesia. Four different implant types were placed based on their surface treatments: resorbable blast media (RBM)-treated implants, hydroxyapatite (HA) implants with an ultra-thin HA film, hydrothermal-treated HA implants coated with HA, and sandblasting combined acid etching (SLA) implants treated with plasma spray and acid etching. A total of 48 implants were divided into two- and four-week groups, with identical dimensions. Each dog received two implants from each group, for a total of eight implants per dog. The implants were securely placed into the superior alveolar bone with a torque greater than 35-N up to a depth of 1 mm. Periotest M (Medizintechnik Gulden e.K., Modautal, Germany) was used to calculate the periotest value (PTV) as a typical value on the buccal side of each implant immediately following placement and sacrifice to test the main fixation and stability of the implants. Resonance frequency analysis (RFA) was utilised by Osstell Mentor (Osstell AB, Gothenburg, Sweden) to simultaneously assess the implant stability quotient (ISQ) on the medial, distal, buccal, and lingual sides of the implant. The rotational torque in one of the sacrificed dogs was calculated using the MGT 50 (ELECTROMATIC Equipment Co., Inc., New York, USA) torque analyzer. The histomorphometric evaluation was performed using an optical microscope (Olympus Corporation, Tokyo, Japan). The upper half's bone-implant contact (BIC), which was found to be more important for implant stability, was studied together with the ratio of the new bone formation area (NBFA) to the complete implant. RESULTS: The maximum stability was observed in HA-treated implants in the fourth week. The minimum stability was observed in hydrothermal-treated HA implants in the fourth week. The stability in each group was greater in the four-week evaluation as compared to the two-week evaluation. The stability was satisfactory in almost all implants at two- and three-week evaluations. The maximum value of the percentage area of newly formed bone at the two- and four-week evaluations was observed in HA-treated implants. The minimum value of the percentage of the area of newly formed bone at two- and four-week evaluations was observed in SLA and RBM-treated implants respectively. The difference was significant statistically (p ≤ 0.05). CONCLUSION: All implant surface modifications, in general, produced satisfactory osseointegration. Excellent osseointegration was seen in the upper portion of the implant with hydrothermally treated HA.

Developmental toxicity triggered by benzyl alcohol in the early stage of zebrafish embryos: Cardiovascular defects with inhibited liver formation and degenerated neurogenesis.

Benzyl alcohol (BnOH) is an aromatic alcohol used worldwide as an excipient in foods, cosmetics, household products, and medications. Although BnOH is a bacteriostatic agent found in many parenteral preparations, this agent is responsible for precipitating the gasping syndrome in premature neonates. Increasing evidence of human exposure to BnOH and environmental contamination of BnOH requires a detailed toxicity assessment of this aromatic chemical. Few studies on the toxicity of BnOH have been reported on different animal models, but its developmental toxicity effects are not fully understood yet. Studies on the effects of BnOH on the specific endpoints of organ toxicity are rare. Thus, the present study aimed to examine the developmental toxicity effects of BnOH by using zebrafish (Danio rerio) embryo as a biological disease model. Four-hour post fertilization zebrafish embryos were exposed to BnOH for 72 h to assess BnOH toxicity on an ecological viewpoint. The median lethal concentrations of varying BnOH concentrations in zebrafish embryos were estimated. The embryonic toxicity induced by BnOH was revealed by the apoptosis in embryos and pathological alterations, such as increased mortality, inhibited hatching rate, and decreased somite number. Moreover, pericardial edema and string heartbeat were observed because of arrhythmia and cardiac malformation. The number of normal vessels in the head and trunk regions was remarkably reduced in transgenic zebrafish line Tg (Fli-1: EGFP). Morphological defects and yolk sac retention were related to the degenerated liver formation in Tg (Lfabp: dsRED). Furthermore, BnOH exposure led to the disruption of motor neuron axonal integrity and the alteration of the axon pattern in Tg (olig2: dsRED). In addition, the results exhibited the pathological effects of BnOH exposure on major organs. We believe that this study is the second to report the developmental organ toxicity of BnOH to zebrafish embryos. This study provides important information for further elucidating the mechanism of BnOH-induced developmental organ toxicity.

Psammous desmo-osteoblastoma with concomitant aneurysmal bone cyst of mandible.

Juvenile psammomatoid ossifying fibroma is a gradually progressive, aggressive extragnathic craniofacial tumor of bone. Due to its complex histogenesis, biological behavior, histology, and classification, its nomenclature has always been the focus of debate among pathologists. Based on the clinical behavior and histology, the term psammous desmo-osteoblastoma (PDO) is an apt expression for this lesion. Immunohistochemical investigation with anti-osteonectin shows positivity for spindle cells whereas psammoma bodies are negative. These results shore up the hypothesis of osteogenic differentiation of the undifferentiated mesenchymal cells of the periodontal ligament that may be responsible for the aggressive behavior of the lesion. Aneurysmal bone cysts (ABCs) are known to be secondarily associated with primary osseous neoplasms like ossifying fibroma, giant cell granuloma, etc. We report a rare case of PDO with concomitant ABC in the mandible of a 30-year-old male patient. The present lesion had recurred at the same site of an osteolytic lesion diagnosed 7 years ago as a benign fibro-osseous lesion and treated by conservative surgical curettage. The histological presentation substantiated by special stains and immunohistochemistry point to the diagnosis of psammous desmo-osteoblastoma with a concomitant ABC. Review of the literature revealed the presentation to be rare with very few cases reported till date.