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.

Liquid crystalline assembly of coil-rod-coil molecules with lateral methyl groups into 3-D hexagonal and tetragonal assemblies.

In this paper, we report the synthesis and self-assembly behavior of coil-rod-coil molecules, consisting of three biphenyls linked through a vinylene unit as a conjugated rod segment and poly(ethylene oxide) (PEO) with a degree of polymerization (DP) of 7, 12 and 17, incorporating lateral methyl groups between the rod and coil segments as the coil segment. Self-organized investigation of these molecules by means of differential scanning calorimetry (DSC), thermal polarized optical microscopy (POM) and X-ray diffraction (XRD) reveals that the lateral methyl groups attached to the surface of rod and coil segments, dramatically influence the self-assembling behavior in the liquid-crystalline mesophase. Molecule 1 with a relatively short PEO coil length (DP=7) self-assembles into rectangular and oblique 2-dimensional columnar assemblies, whereas molecules 2 and 3 with DP of 12 and 17 respectively, spontaneously self-organize into unusual 3-dimensional hexagonal close-packed or body-centered tetragonal assemblies.

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.

808 nm NIR Laser-Excited Upconversion Nanoplatform for Combinatory Photodynamic and Chemotherapy with Deep Penetration and Acid Bursting Release Performance.

Combinatory photodynamic and chemotherapy have demonstrated superior performance in cancer ablation over singular therapeutics. However, photodynamic therapy (PDT) often exhibits suboptimal efficacy for deep-seated tumors, owing to the limited penetration depth of illumination light, while chemotherapy is generally accompanied by severe side effects. Therefore, it is imperative to develop a functional nanoplatform for combinatory PDT and chemotherapy, which could, for PDT, achieve enhanced light penetration and, for chemotherapy, realize reduced therapeutic threshold dosage and a controllable drug release profile (e.g., minimized release in blood circulation but bursting release in the tumor microenvironment). Herein, we demonstrate a therapeutic nanoplatform composed of poly(acrylic acid) (PAA)-modified silica-coated Nd3+-doped upconversion nanoparticles decorated with methylene blue (MB) and doxorubicin (DOX) in silica and a PAA layer, respectively. Notably, 808 nm light is used to excite upconversion nanoparticles and further trigger the photosensitization behavior of MB in PDT, while the quick acid response of the PAA layer in the tumor acid environment introduces DOX bursting for optimized chemotherapy with significantly decreased therapeutic threshold dosage and minimized side effects. Importantly, the anticancer efficiency of the nanoplatform in vitro and in vivo shows an IC50 and a tumor inhibition rate of 12.55 µg mL-1 and 89.81%, respectively. This study provides a strategy for combinatory cancer therapy.

The current strategy of repair of tetralogy of Fallot in children and adults.

OBJECTIVES: The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function. METHODS: From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years +/-0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium. RESULTS: The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months. CONCLUSIONS: Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.

Accelerating bone generation and bone mineralization in the Interparietal sutures of rats using an rhBMP-2/ACS composite after rapid expansion.

This study aims to investigate the effects of rhBMP-2/ACS composite on bone regeneration and mineralization during expansion of the interparietal suture in rats. Forty 10-week-old Sprague-Dawley rats were divided into four groups (n=10). The first group (intact group) did not receive any intervention. The second group (expansion control group) received an expansion force of 60 g. The remaining two groups received an expansion force of 60 g and were implanted with an atelo-type I absorbable collagen sponge and rhBMP-2/ACS composite positioned on the suture beneath the periosteum. The relapse, relapse ratio, relevant bone remodelling, and calcium and osteocalcin contents were evaluated. Bone regeneration in the interparietal suture was estimated by the histological method. The osteocalcin content was measured by radioimmunoassay, and the calcium content was measured by atomic absorption spectrophotometry. Bone regeneration was more active in the suture after application of the expansion force compared with that of the suture without any intervention. Bone bridges formed in the rhBMP-2/collagen composite group. Both osteocalcin and calcium content were higher in the rhBMP-2/collagen composite group than in the other three groups (P<0.01). The relapse ratio in the rhBMP-2/collagen group was much lower than that in the other two expansion groups (P<0.01). RhBMP-2/ACS composite can promote bone regeneration and bone mineralization in the expanded suture and decrease the relapse ratio. Thus, the rhBMP-2/ACS composite may be therapeutically beneficial to the inhibition of relapse and shortening of the retention period during rapid expansion.

[Clinical observation of alveolar bone status of ankylos dental implants with completion of restoration].

OBJECTIVE: To provide basis for clinical application of ANKYLOS dental implants by following up alveolar bone status of 318 pieces of restored ANKYLOS dental implants. METHODS: Between February 2008 and August 2009, 170 patients with dentition defect underwent placement of ANKYLOS dental implants (318 pieces). There were 74 males (133 pieces) and 96 females (185 pieces) with an average age of 43.8 years (range, 23-68 years). After operation, the periapical X-ray films were taken to observe osseointegration around the neck of implant, alveolar bone resorption, and survival of implants. RESULTS: All patients were followed up at 6, 12, and 24 months after operation. There were 9 failure implants with a total dental implants survival rate of 97.17% (309/318): 3 at 6 months, 4 at 6-12 months, and 2 at 12-24 months, showing no significant difference in dental implants survival rate among 3 time points (chi2=0.470 3, P=0.492 8). New bone formed around the neck of implant in 4 cases at 6 months and in 31 cases at 12 months; at 6, 12, and 24 months, the bone increase was (0.392 7 +/- 0.217 4), (0.633 5 +/- 0.202 1), and (0.709 0 +/- 0.199 1) mm, respectively, showing significant differences among 3 time points (P < 0.05). At 6, 12, and 24 months after operation, the bone loss of other patients was (0.392 7 +/- 0.217 4), (0.716 7 +/- 0.220 3), and (0.723 2 +/- 0.215 4) mm, respectively, showing significant differences among 3 time points (P < 0.05). CONCLUSION: After restoration with ANKYLOS dental implant, alveolar bone status is good and the implant success rate is high during short-term follow-up. But further observation and study are required for long-term effectivness.

Application of ultrasonic inspection in monitoring dynamic healing of mandibular fracture in rabbit model.

OBJECTIVE: To investigate the feasibility of ultrasonic diagnosis for monitoring fracture healing. METHODS: Thirty rabbit models with fraction of mandible body were established by surgically removing partial lower jawbone. At the 1st, 2nd, 4th, 6th, 8th and 12th week after the operation, they were examined by X-ray and ultrasound, respectively. All detection results were scored according to a generally accepted standard. Spearman rank correlation analysis was conducted to explore the relationship between the results of the two inspection methods. RESULTS: In each healing stage, the results of the ultrasonic inspection were basically consistent with those of the X-ray examination, as supported by a Spearman rank correlation coefficient of 0.892 (P<0.001). CONCLUSIONS: Non-invasive ultrasonic inspection can be used instead of X-ray examination to monitor and diagnose fracture healing.

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.

[Pulsed Nd:YAG laser-aided debonding for removing the metal brackets].

OBJECTIVE: To explore the possibility of pulsed Nd:YAG laser-aided debonding for removing orthodontic metal brackets and to compare the method with the conventional mechanical debonding method. METHODS: Fifty healthy premolars extracted for orthodontic purpose were randomly divided into five groups (10 teeth in each group). There were four experimental groups and one control group. Every tooth was bonded with bracket. Laser was used to irradiate the teeth in experimental groups with different electric currents (13.0, 13.5, 14.0, 14.5 A). During the irradiation, the brackets received 4.9 N of force until the brackets off. The time needed for debonding and the temperature change of the pulp cavity were recorded. The teeth in control group were debonded using mechanical method. The adhesive remnant index (ARI) was calculated using stereomicroscope and imagetool software. All samples were examined with a scanning electron microscope. RESULTS: The time taken between the four groups were (67.70 ± 7.18), (35.90 ± 4.28), (24.90 ± 3.76), (6.90 ± 2.33) s, highly statistical difference was found in the time needed for debonding (P < 0.01). The temperature in the pulp cavity among the four groups were (20.97 ± 3.10), (12.75 ± 3.14), (8.99 ± 2.47), (2.91 ± 1.88)°C, and statistical differences were found in temperature change of the pulp cavity (P < 0.05). ARI of three experimental groups and the control group were (8.55 ± 5.02)%, (15.42 ± 7.37)%, (5.55 ± 3.79)%, (13.72 ± 6.69)%, and (74.36 ± 29.44)%. The enamel surface of the control group was coarse with deep scratchs. The enamel surface was smooth and clean in the experimental groups. CONCLUSIONS: Pulsed Nd:YAG laser-aided debonding for removing metal brackets was feasible. Laser-aided debonding was better than conventional mechanical debonding method. The method reduced the damage to the enamel surface.

[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.