Clinical and histologic evaluation of effects of hyaluronic acid in rat tongue

Clinical and Histological Effects of Calcium Hydroxyapatite Filler in the Orofacial Region: A Study in Rats

BACKGROUND

Calcium hydroxyapatite (CaHA) dermal filler has been increasingly used in facial aesthetic procedures.

OBJECTIVE

To investigate clinical and histological changes associated with calcium hydroxyapatite (CaHA) dermal filler in the orofacial region.

MATERIALS AND METHODS

Forty-eight female Wistar rats were divided into CaHA and control groups. The material was applied in the ventral tongue and the submandibular region; the animals were euthanized after 7, 30, and 90 days.

RESULTS

After 7 days, yellowish nodules with a firm consistency were observed on the tongue. In 2 animals, the material migrated to the base of the tongue. Histopathological examination revealed CaHA spheres surrounded by an infiltrate, predominantly composed of macrophages. In the CaHA group, the percentage of collagen in the tongue and dermis was higher compared with the control group (p < .05) at both 30 and 90 days. The thickness of the epidermis/dermis was also higher in the CaHA group (p < .05). In 5 submandibular glands containing material, areas of edema and hyperemia were observed, along with infiltrates of neutrophils, lymphocytes, and plasma cells. Changes in the morphology of ducts and acini in adjacent regions were evident.

CONCLUSION

CaHA exhibits satisfactory properties for filling and collagen biostimulation in the tested regions. Further studies are required to explore the potential for migration and the glandular alterations.

Topical application of Aloe vera and vitamin E on induced ulcers on the tongue of rats subjected to radiation: clinical and histological evaluation

OBJECTIVE

The aim of this study is to assess the effect of two types of antioxidants, vitamin E (VE) and Aloe vera (AV), on healing of induced oral lesions after radiation in a murine model by clinical and histological analysis.

METHODS

The animals were randomly divided into three groups of 12 animals each (400 mg VE, 70 % AV and control) and two time periods (5 and 7 days). They were irradiated with a single dose of 30 Gy, and after 24 h, a lesion was produced on the ventral tongue of each animal. The products were applied daily in their respective group until euthanasia.

RESULTS

On clinical analysis, there was a higher frequency of lesions in the animals of the control group at both periods. The area of the lesions was also greater in the control group compared with the groups AV and VE (5 days p = 0.006; 7 days p = 0.002). On microscopic analysis, the degree of inflammation differed between the study groups and experimental periods. At 5 days, the statistical difference was not significant among the groups evaluated, but at 7 days, animals in the control group showed intense inflammation, while those in groups VE and AV exhibited mild to moderate inflammation (p = 0.002).

CONCLUSION

The results suggest that VE and AV contributed to the decrease in inflammatory response and healing of the lesions induced on the tongue of rats subjected to radiation.

Effect of Different Irrigating Solutions and Photo-Activated Therapy for In Vivo Root Canal Treatment

This study aimed to evaluate histologically the effect of irrigation with 400 ppm Sterilox, 2% and 5% sodium hypochlorite (NaOCl), with and without photo-activated therapy (PAD), in a single-visit root canal treatment of dog's teeth with apical periodontitis (AP). Ten dogs were randomly divided into two groups (n=5): with and without PAD, and the root canals into four subgroups, according to the irrigating solution: SX (400 ppm Sterilox), SH2 (2% NaOCl), SH5 (5% NaOCl) and SS (saline solution) as positive control. A total of 134 root canals were opened and left exposed to the oral environment for 14 days and then sealed for 60 days for AP induction. Then, root canals were treated according to each proposed disinfecting protocol and filled in the same session. After 120 days, the dogs were euthanized and the periapical inflammatory events were evaluated under light microscopy. Qualitative data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). PAD did not produce significant differences in the scores for apical inflammation when used after chemo-mechanical preparation (p>0.05). The irrigating solutions SX, SH2 and SH5 without PAD were statistically different from SS (p<0.05) that presented the greatest scores for apical inflammation. PAD did not show any additional effect for the treatment of root canals with pulp necrosis and AP in a single visit and 400 ppm Sterilox may be considered an alternative to NaOCl in root canal treatment.

Local and systemic tissue response submitted to injection of 2 and 30% polymethylmethacrylate in rats' tongue

INTRODUCTION

Adverse effects on the oral mucosa after the use of dermal fillers have been reported due to their increased use for facial aesthetics.

OBJECTIVE

This study aimed to evaluate, clinically and histologically, the local and systemic effects of two concentrations of polymethylmethacrylate (PMMA) dermal filler in rats.

MATERIAL AND METHODS

Fifty-four female rats were allocated into three treatment groups (2% PMMA, 30% PMMA and 0.9% NaCl), according to the substance injected in the tongue, and three experimental periods: 7, 60 and 90 days. The rats were clinically evaluated and then euthanised, and their tongue and right kidney removed. The histological sections were stained with haematoxylin/eosin and picrosirius.

RESULTS

Clinically, significant differences were found between test groups as to the occurrence of nodules (Kruskal-Wallis; p < 0.001). Histologically, there was greater inflammatory response in the PMMA compared with control (Kruskal-Wallis; p < 0.001). 30% PMMA had greater collagen formation (anova mixed models; p < 0.01). No migration of the material towards kidney was found.

CONCLUSION

Polymethylmethacrylate induced intense reaction in the initial period of observation (7 days), followed by gradual decrease during the study, favouring the presence of fibroplasia adjacent to the material.

Polymethylmethacrylate dermal fillers: evaluation of the systemic toxicity in rats

This study evaluated local and systemic reactions after an intravascular injection of polymethylmethacrylate (PMMA) at two concentrations in a murine model. Thirty rats were divided equally into three groups: 2% PMMA, 30% PMMA, and a control group (normal saline only injection). The filler was injected into the ranine vein. The rats were sedated at 7 and 90 days and a clinical evaluation performed. After euthanasia, the right lung, liver, and right kidney were removed, weighed, and microscopically analyzed. The submandibular lymph nodes and tongue were removed and examined microscopically. Serum was subjected to liver and kidney function tests. No groups showed clinical alterations. Microspheres were not observed at any distant organ. Two samples from the 2% PMMA group showed a local inflammatory response at day 7 and another two samples from the 30% PMMA group at day 90. The group injected with 30% PMMA presented higher levels of alanine aminotransferase (P = 0.047) after 90 days when compared with the other groups. The data obtained in this study demonstrate that intravascular injections of PMMA fillers show potential health risks such as chronic inflammation at the implantation site.