Effect of skimmed pasteurized milk and Hank's balanced salt solution on viability and osteogenic differentiation of human periodontal ligament stem cells

Comparative evaluation of periodontal ligament fibroblasts stored in different types of milk: effects on viability and biosynthesis of collagen

Milk remains one of the most frequently recommended solutions for storage of avulsed teeth because it can maintain cell viability and is easily accessible. However, some negative effects of milk on avulsed teeth have been reported, just as the effects of milk on the long-term functions of cells are not clear. This study aimed to evaluate the effects of different types of milk on the viability, proliferation, and functions of periodontal ligament fibroblasts (PDLF)s in vitro. Human PDLFs were culture-medium depleted for 5 min and stored in Hanks' balanced salt solution (HBSS), whole cow's milk, low-fat cow's milk, or almond milk for 1 h at 25°C. Cell viability and proliferation were assessed using MTT assays. Expression of the genes encoding type I collagen and its modifying enzymes were analyzed using real-time PCR. Collagen matrix production was evaluated using Picrosirius red polarization. Our results showed the overall efficiency of low-fat cow's milk in maintaining the viability and proliferation of PDLFs, and in enhancing the process of collagen production. Almond milk storage resulted in the highest rate of PDLF proliferation, and comparable collagen biosynthesis ability to the control. Therefore, besides low-fat cow's milk, almond milk may potentially be an alternative tooth-storage medium for PDLF preservation and PDL tissue regeneration.

Evaluation of laser phototherapy (λ 780 nm) after dental replantation in rats

BACKGROUND/AIM

Tooth replantation is the treatment of choice in cases of avulsion although the outcomes are variable. The teeth can be lost due to external root resorption. The aim of this study was to histologically assess of the effect of laser phototherapy (λ780 nm) on replanted teeth in rats.

MATERIAL AND METHODS

Sixty Wistar Albinus rats had their maxillary right incisors extracted and were then divided into four groups: G1-absence of storage medium; G2-milk as storage medium; G3-milk as storage medium followed by a laser irradiation of the root surfaces and entrance of the alveolus (λ = 780 nm; P = 70 mW; CW; DE = 21 J/cm² ); G4-milk as storage medium, laser irradiation as in G3 before replantation. After this procedure, laser irradiation was performed on the buccal and palatal mucosa (8.4 J/cm² per session) every 48 h for 15 days. The animals were euthanized 15, 30, and 60 days after replantation.

RESULTS

The histological results showed that after 15 days, G4 exhibited intense chronic inflammation with the presence of clastic cells and moderate external inflammatory root resorption (P < 0.05) when compared with G3, in which these outcomes were not observed. At the 30th day, G1, G2, and G4 showed chronic inflammation varying from discrete to moderate, as well as intense external inflammatory root resorption. G3 remained without any inflammation and external inflammatory root resorption up to the 60th day.

CONCLUSIONS

The use of laser phototherapy on the root surface and at the entrance of the alveolus prior to replantation had a positive biomodulative effect on alveolar repair after tooth replantation in rats.

Effect of laser photobiomodulation on the periodontal repair process of replanted teeth

BACKGROUND/AIM

Tooth replantation is the optimal treatment in cases of avulsion. However, its success is limited due to the occurrence of external root resorption. The aim of this study was to assess the effect of laser photobiomodulation (LPBM) at λ808 nm and λ660 nm and of storage media on the periodontal repair process of replanted teeth in rats.

MATERIAL AND METHODS

Sixty maxillary right incisors were extracted from sixty Wistar rats and randomly assigned to six groups (n = 10). Groups consisted of 10 teeth stored in paper napkins (PN), whole milk (WM), and soy milk (SM), for 45 min; and PNL, WML and SML, in which teeth were stored in the same storage media, but the root surface and the alveolus were treated with LPBM at λ808 nm before replantation, and the buccal and palatal mucosa of the alveolus were treated with LPBM at λ660 nm after replantation. Five rats from each group were euthanized after 15 or 30 days. The right hemimaxilla including the replanted incisor was removed and processed for histomorphometric analysis to assess root resorption areas, replacement root resorption, perimeter with ankylosis and periodontal repair, and areas of type I and III collagen deposition, using the ImageJ 1.50b software. Data were analyzed statistically by anova followed by Tukey's multiple comparison test (α = 5%).

RESULTS

WM and SM showed smaller root resorption areas and higher collagen deposition in both experimental periods, and SM showed the largest perimeter of periodontal repair. LPBM reduced the occurrence of root resorption only in the PNL group, both at 15 and 30 days, and increased the perimeter of periodontal repair in all groups at 30 days. There was higher collagen deposition in the irradiated groups regardless of the experimental period.

CONCLUSIONS

The LPBM protocol at λ808 nm and λ660 nm as well as whole milk and soy milk favored the periodontal repair process of replanted teeth in rats.