Effect of autologous platelet-rich plasma in combination with bovine porous bone mineral and bio-guide membrane on bone regeneration in mandible bicortical bony defects.

OBJECTIVE: Growth factors contained in platelet-rich plasma (PRP) can induce osteoblast differentiation in certain studies, whereas in others, osteogenesis of PRP on mandible bone defects has not been proved clinically. The aim of the study was to investigate the effect of autologous PRP on the osteogenic potential of combining bovine porous bone mineral (BPBM) and bio-guide membrane (BGM) in promoting mandible bicortical bony defects in rabbits. METHODS: One circular mandible bicortical bony defects were created in each of 54 rabbits, which were divided into 3 groups: group 1: 18 of the defects were left unfilled as a negative control; group 2: 18 of the defects were grafted with autologous PRP and BPBM/BGM; group 3: 18 of the defects were grafted with BPBM/BGM without PRP. Animals were killed at 4, 8, and 12 weeks after operation. Harvested tissue and specimens were evaluated histologically and radiographically, and metabolized observation was performed. Histological parameters associated with osteoblast activities, bone trabecula, neovascularization, newly formed mineralized bone, rudimental grafts and connective tissue formation were measured. Densities of the bones at 4, 8, and 12 weeks were studied by radiographic. The bone defect closure ratio was measured at 12 weeks. The bone metabolized parameter alkaline phosphatase was also measured and compared between 4, 8, and 12 weeks. RESULTS: The platelet concentration of PRP is 4.19- to 4.43-fold to that of the whole blood. Histological analysis showed new bone formation at all therapeutic sites including BPBM/BGM grafts with or without PRP. A statistically significant difference in new bone formation between group PRP/BPBM/BGM and group BPBM/BGM was observed. Untreated defects of group control showed the less bone regeneration. There was significant difference of bone density between group PRP/BPBM/BGM and control, and group BPBM/BGM and control, at 4, 8, and 12 weeks postoperative. There were more bone defects filling, and the grafts were absorbed at 12 weeks of group PRP/BPBM/BGM compared with group BPBM/BGM. Defects treated with PRP/BPBM/BGM demonstrated significantly increased activity of osteoblasts, enhanced amount of mitochondria and rough endoplasmic reticulum in osteoblasts, and increased concentration of alkaline phosphatase at 4, 8, and 12 weeks compared with those treated with BPBM/BGM and control group. Complete closure ratio of bone defects treated with PRP/BPBM/BGM (50%) was significantly increased compared with that treated with BPBM/BGM (16.6%). CONCLUSIONS: The study suggested that PRP combination of BPBM and BGM had significant therapeutic effects on mandible bicortical bony defects of rabbits. The effects are associated with the high concentration of platelet in PRP and the porous configuration of BPBM. Although we cannot reveal the detailed statistical relationship of PRP on promoting BPBM/GBM osteoinductive effects, PRP demonstrated superior results of bone regeneration.

Therapeutic effects of diode laser on vascular epulis in esthetic area.

Vascular epulis is a rare clinical disease. In our study, a case of vascular epulis in the cosmetic area was treated by diode laser, without recurrence and obvious inflammation in the surgical site 5 years after surgery. This case report indicates that the excision of vascular epulis in the cosmetic area of the anterior teeth by diode laser could be an alternatively safe and complementary approach in lieu of conventional surgery.

[Effects of fast decompression on prostaglandins content in cerebral tissue of guinea pigs].

Objective. To investigate the effect of fast decompression on prostaglandins in cerebral tissue. Method. 26 guinea pigs were divided into 2 groups randomly. The animals in group FDC (group 1) were treated with fast decompression and formed decompression sickness, but those in control group (group 2) were not treated with decompression. The contents of prostaglandin E2 (PGE2), 6-keto-prostaglandin F1a (6-K-PGF1a) and thromboxane B2 (TXB2) in cerebral tissue of the animals were determined by enzyme immunoassay. Result. The content of PGE2 in cerebral tissue of FDC animals was twice as much as that in control animals. The content of TXB2 in cerebral tissue of FDC animals was 3 times as high as that in control animals, and that of 6-K-PGF1a in cerebral tissue of FDC animals was 2.6 times as that in control animals. It showed very significant differences as compared with control group (P<0.01). Conclusion. The content of PGs in cerebral tissue increased markedly after fast decompression, and may cause cerebral injury.

Effects of hyperbaric oxygen on aggressive periodontitis and subgingival anaerobes in Chinese patients.

OBJECTIVE: To investigate the effects of hyperbaric oxygen (HBO2) on aggressive periodontitis (AgP), and subgingival obligate anaerobes in Chinese patients. MATERIALS AND METHODS: Sixty cases of Chinese patients with AgP were randomly divided into two groups -the HBO2 group (30 cases) and the control group (30 cases). Study teeth were divided into four groups -: the HBO2 therapy, the HBO2 + scaling scaling group, the scaling group and the control group. Subgingival anaerobic organisms were measured with anaerobic culture, and number of obligate anaerobes and facultative anaerobes and Bacteroides melaninogenicus was counted. Comparisons of changes in the clinical indices, and subgingival anaerobes were made between the groups. RESULTS: Highly significant differences in gingival index (GI), probing depth (PD), attachment loss (AL), and Plaque index (PLI), and tooth odontoseisis (TO) were seen in the HBO2, the HBO2 + scaling and the scaling groups when compared with the control group (P<0.01). The number of subgingival anaerobes as well as the types of obligate anaerobes and facultative anaerobes and the number of Bacteroides melaninogenicus were reduced markedly in these three treatment groups. Highly statistical differences in clinical indices, subgingival anaerobe number and types of obligate anaerobes and facultative anaerobes and Bacteroides melaninogenicus were found when comparisons were made between the HBO2 + scaling and the HBO2 groups, as well as between the HBO2 + scaling and the scaling groups. Clinical follow-ups indicated that the GI, PD, AL, TO, PLI and subgingival anaerobes number of the three therapeutic groups were reduced more severely than the control group. CONCLUSIONS: HBO2 had good therapeutic effects on Chinese patients with AgP. HBO2 therapy combined with scaling and root planing was the most beneficial in the treatment of AgP. The therapeutic effect of HBO2 on AgP is most likely through inhibition of the growth of subgingival anaerobes. Clinical follow-ups suggest that the effect could last more than 2 years.

[Effects and holding time of hyperbaric oxygen on human severe periodontitis].

OBJECTIVE: This paper studied the therapeutic effects and holding time of hyperbaric oxygen (HBO) on human severe periodontitis. METHODS: 30 cases with periodontitis were selected and randomly divided into 2 groups, i.e. the HBO group and control group. For HBO group, they were exposed to a pressure of 0.25 MPa. For control group, they were rinsed with gargle. Gingival indices (GI), sulcus bleeding indices (SBI), plaque index (PLI), probing depth (PD), attachment loss (AL) and gingival crevicular fluid (GCF) were measured during both the first and last clinical visits, and 1 year after HBO therapy. The gingival blood flow (GBF) were measured by Laser Doppler Flowmeter. RESULTS: HBO can decrease GI of patients with periodontitis by 1.1 decrease SBI by 1.2, lower PD and AL by 0.7 mm, decrease the volume of GCF by 2.0, and significant differences could be seen in the above indices between pre and post HBO therapy. The GBF had a 1.8 folds increase after HBO exposure. GI and SBI one year after HBO therapy were larger than that of the time after HBO therapy. There were no significant differences in the PLI, PD, AL, GCF, GBF between post HBO therapy and 1 year after HBO therapy. CONCLUSION: HBO had good therapeutic effects on human severe periodontitis, the effects can keep more than 1 year.