Chemical Fixation Importance of Histologic Samples for Staining of Proliferated Bone During Implant Osseointegration

This study aimed to obtain as much and as accurate information as possible about the process of osseointegration of titanium implants, through histological processing. For this purpose, the combination of a mercury chloride fixator (Stieve mixture) and a complex staining method (Goldner’s trichrome) was used, which can highlight the microscopic structures in several colors and shades. The Stieve mixture proved to have distinguished qualities both in the preservation of basophilic and acidophilic structures and especially in the chemical preparation of the substrate for the binding of each structural component with a specific acidophilic dye. On the substrate thus prepared, the acidophilic dyes used in the Goldner’s trichrome staining highlighted the structural components in different colors and shades, offering the possibility of high precision assessment of the newly proliferated bone, in different stages of proliferation, consolidation and reshaping. Complex information was obtained, which allows the appreciation of osseointegration for endosseous implants and the amount of proliferated bone at the bone-implant interface, the stage of proliferation, consolidation and reshaping of the mature bone, the degree of fixation to deep bone structures. The possibility of complex assessment of the osseointegration process for endosseous implants at a given time is of great practical importance for correct assessment of the waiting time required for safe installation of prosthesis. The combination of Stieve fixator mixture with Goldner’s trichrome staining method has proven to be very effective in histology, highlighting on excellent level the existing structural components of each stage, in which the osseointegration process goes through. A very important role in this combination was achieved by mercury chloride mixture, which prepared the substrate for specific reaction with dyes. Regarding the results obtained, we recommend this combination for histological investigations aimed on bone proliferation and repair.

Comparative features of the mucous glands in the gastroduodenal junction in guinea pigs and chinchillas: microanatomy and histochemistry

Background: Mucous glands from the gastroduodenal junction are briefly represented by glandular cells in the stomach and by Brunner’s glands in the duodenum. The aim of the study was to describe the main histological/histochemical features of the gastroduodenal junction in guinea pigs and chinchillas. Results: The material was represented by tissue samples collected from the stomach and duodenum processed by paraffin technique. Histological sections were stained by Goldner’s trichrome stain, while mucous content was identified by Periodic acid–Schiff (PAS) stain (for neutral mucosubstances) and Alcian blue stain (for acid mucosubstances). In guinea pig, the pyloric glands were positive for both mucus types, whereas in chinchillas a low amount of mucin was identified. The Bruner glands, in guinea pigs displayed a weak reaction for the both mucin types. In chinchillas, the Bruner glands showed a significantly higher amount of PAS and Alcian blue-positives mucosubstances types. As observed, a higher amount of neutral mucus was identified in the pyloric glands in guinea pigs comparing to chinchillas. Contrariwise, chinchillas displayed a suggestively higher amount of mucus in Bruner glands comparing to guinea pigs. Conclusions: Concluding, this is the first report describing the comparative features of the mucous glands in the two rodents, with detailed histological and histochemical features.

Histological aspects of the esophagus in guinea pigs (Cavia porcellus)

The aim of this study is the detailed description of the esophageal microscopic structure in guinea pigs. Fragments from the cervical, thoracic and abdominal segments of the esophagus were processed for classical paraffin embedding and the sections were stained by hematoxylin-eosin and Goldner’s trichrome methods. The esophagus in guinea pigs is lined by keratinized stratified squamous epithelium and there are no glands in the lamina propria and the submucosa. The muscularis mucosae is formed by smooth muscle cells disposed longitudinally. The muscularis externa is formed by striated muscle cells disposed on 3 layers in the first 2 thirds of the esophagus, while in some regions of the abdominal segment’s circumference, the cells form 4 layers.

Assessing the intralobular ducts in mouse mandibular gland

In order to quantify the types of intralobular ducts, we used five adult male mice, sacrificed by cervical dislocation, after exposure to anesthetic. After euthanasing the animals, the mandibular glands were histologically processed. We sectioned the tissue at 5 µm thickness and stained the slides using Goldner’s trichrome staining procedure. We captured images on four different microscopic fields for each animal, subsequently counting each type of intralobulary duct. The granular ducts were the most numerous, followed by the intermediary ones and striated ducts with the lowest number.

Observations regarding the structure of the parotid and mandibular glands in rabbit

Our study aims to investigate the histological structure of two major salivary glands in adult rabbit. We used 5 adult rabbits, 3 males and 2 females, from a private breeder in Cluj. We harvested the salivary glands, fixed them in 10% buffered formalin, dehydrated in ethanol (increasing concentration), clarified in n-butanol and embedded in paraffin. The sections (5 µm thickness) were stained with Goldner’s trichrome method and examined with an Olympus BX41 light microscope. Histologically, parotid gland in rabbit contains only one type of acini, which presents morphological characteristics of serous acini. In mandibular gland, the acini are all the same, similar to the ones in parotid gland. Concerning the general aspect and dimension they are much larger and polymorphic.

Uninfiltrated Collagen in Hybrid Layers produced after Reduced Acid-etching Time on Primary and Permanent Dentin

ABSTRACT Aim This study evaluated the influence of acid-etching time on collagen exposure in adhesive interfaces established on primary and permanent dentin. Materials and methods Flat dentin surfaces were produced on sound primary molars and premolars (n = 8). The surfaces were divided into mesial and distal halves, and each half was etched with phosphoric acid for 5 or 15 seconds. The teeth were randomly allocated into two groups according to the adhesive system applied: Prime & Bond NT or Prime & Bond 2.1. After the adhesive application, the specimens were processed for Goldner's trichrome staining. The thickness of the uninfiltrated collagen zone (UCZ) in the hybrid layer was measured under optical microscopy. Data were analyzed by analysis of variance and Tukey tests (α = 0.05). Results The thickness of UCZ was adhesive dependent. Within the same substrate, the specimens treated with Prime & Bond 2.1 presented thicker UCZ when etched for 15 seconds. Collagen exposure was significantly higher for the primary teeth etched for 5 seconds and treated with Prime & Bond 2.1. Conclusion The thickness of UCZ in hybrid layers is directly affected by acid-etching time and by the adhesive system applied. Primary dentin seems to be more susceptible to collagen exposure than is permanent dentin. Clinical significance Both acid-etching time and adhesive system can influence the amount of exposed collagen interfering on resin–dentin bond quality, especially on primary dentin. How to cite this article Scheffel DLS, Huck C, Soares DG, Basso FG, de Souza Costa CA, Brackett MG, Pashley DH, Hebling J. Uninfiltrated Collagen in Hybrid Layers produced after Reduced Acid-etching Time on Primary and Permanent Dentin. J Contemp Dent Pract 2016;17(10):861-866.

[18F]-sodium fluoride PET/CT is an imaging-derived biomarker of hydroxyapatite expression in carotid plaque: sub-study of the Canadian Atherosclerosis Imaging Network (CAIN-2)

Background: It has been hypothesized that [18F]-sodium fluoride (NaF) uptake imaged with positron emission tomography (PET) binds to hydroxyapatite molecules expressed in regions with active calcification. Therefore, we aimed to validate NaF as a marker of hydroxyapatite expression in high-risk carotid plaque. Methods: Eleven patients (69 ± 5 years, 3 female) scheduled for carotid endarterectomy were prospectively recruited for NaF PET/CT. One patient received a second contralateral endarterectomy; two patients were excluded (intolerance to contrast media and PET/CT misalignment). The bifurcation of the common carotid was used as the reference point; NaF uptake (tissue to blood ratio - TBR) was measured at every PET slice extending 2 cm above and below the bifurcation. Excised plaque was immunostained with Goldner’s Trichrome and whole-slide digitized images were used to quantify hydroxyapatite expression. Pathology was co-registered with PET. Results: NaF uptake was related to the extent of hydroxyapatite expression (r=0.45, p<0.001). Upon classifying bilateral plaque for symptomatology, symptomatic plaque was associated with cerebrovascular events (3.75±1.1 TBR, n=9) and had greater NaF uptake than clinically silent asymptomatic plaque (2.79±0.6 TBR, n=11) (p=0.04). Conclusion: NaF uptake is related to hydroxyapatite expression and is increased in plaque associated with cerebrovascular events. NaF may serve as a novel biomarker of active calcification and plaque vulnerability.