Periodontitis is caused by overactive osteoclast activity that results in the loss of periodontal supporting tissue and mesenchymal stem cells (MSCs) are essential for periodontal regeneration. However, the hypoxic periodontal microenvironment during periodontitis induces the apoptosis of MSCs. Apoptotic bodies (ABs) are the major product of apoptotic cells and have been attracting increased attention as potential mediators for periodontitis treatment, thus we investigated the effects of ABs derived from MSCs on periodontitis. MSCs were derived from bone marrows of mice and were cultured under hypoxic conditions for 72 h, after which ABs were isolated from the culture supernatant using a multi-filtration system. The results demonstrate that ABs derived from MSCs inhibited osteoclast differentiation and alveolar bone resorption. miRNA array analysis showed that miR-223-3p is highly enriched in those ABs and is critical for their therapeutic effects. Targetscan and luciferase activity results confirmed that Itgb1 is targeted by miR-223-3p, which interferes with the function of osteoclasts. Additionally, DC-STAMP is a key regulator that mediates membrane infusion. ABs and pre-osteoclasts expressed high levels of DC-STAMP on their membranes, which mediates the engulfment of ABs by pre-osteoclasts. ABs with knock-down of DC-STAMP failed to be engulfed by pre-osteoclasts. Collectively, MSC-derived ABs are targeted to be engulfed by pre-osteoclasts via DC-STAMP, which rescued alveolar bone loss by transferring miR-223-3p to osteoclasts, which in turn led to the attenuation of their differentiation and bone resorption. These results suggest that MSC-derived ABs are promising therapeutic agents for the treatment of periodontitis.
Humans ; Osteoclasts ; Alveolar Bone Loss/therapy* ; Cell Differentiation ; MicroRNAs ; Periodontitis/therapy* ; Extracellular Vesicles ; Apoptosis ; Mesenchymal Stem Cells

Although intentional replantation is frequently used as a treatment modality for endodontic problems, severe periodontal involvement has usually been regarded as a contraindication. However, there are some studies suggesting that intentional replantation could be a successful treatment alternative for periodontally involved teeth. This paper reports the treatment of a tooth with severe periodontal involvement using intentional replantation. The tooth, which had had root canal therapy due to endodontic-periodontal combined lesion but showed extensive bone loss, was gently extracted and replanted after thorough debridement of the root surface. By intentional replantation, a tooth with severe periodontal involvement in this case could be preserved, without extraction, over the course of a 3-year follow-up period.
Alveolar Bone Loss ; Debridement ; Follow-Up Studies ; Periodontal Attachment Loss ; Periodontal Diseases ; Replantation ; Root Canal Therapy ; Tooth Replantation ; Tooth

OBJECTIVETo evaluate the orthodontic treatment outcome in patients with impacted maxillary central incisor in the mixed dentition.

METHODSNine patients, aged 8 to 11 years, with impacted maxillary central incisor were treated orthodontically. The cone-beam CT(CBCT) was taken before treatment, after treatment and one year out of retention to evaluate the root length, root canal wall thickness, width of the apical foramen, and degree of root bending, alveolar bone height and thickness. The crown-to-root ratio was calculated. The periodontal and endodontic conditions were evaluated. The parameters of the treated incisors and contralateral ones served as controls were compared.

RESULTSNine impacted teeth were treated successfully. Throughout the treatment, the root of impacted central incisor continued to develop and the alveolar bones also continued to develop and remodel. The condition of the alveolar bone of vertically impacted teeth was better than that of horizontally impacted ones. No periodontal pocket or pulp necrosis was found after treatment. Seven patients were examined one year after treatment. No significant difference was found in root length, palatal alveolar bone level and palatal alveolar bone thickness. The control group root length was (13.07±2.15) mm, the treatment group root length was (12.06±2.00) mm. No further alveolar bone loss, gingival recession and pulp necrosis were found. The control group labial and palatal alveolar bone levels were (0.90±0.62), (0.45±0.52) mm, labial and palatal alveolar bone thickness were (0.85±0.14), (1.21±0.41) mm. The treatment group labial and palatal alveolar bone levels were (2.18±1.59) mm, (0.57±0.71) mm, labial and palatal alveolar bone thickness were (0.48±0.29), (1.43±0.31) mm.

CONCLUSIONSOrthodontic therapy for impacted maxillary central incisor in the mixed dentition could promote root development and alveolar bone remodeling. Good periodontal and endodontic conditions were achieved.

Alveolar Bone Loss ; diagnostic imaging ; Child ; Cone-Beam Computed Tomography ; Dentition, Mixed ; Gingival Recession ; diagnostic imaging ; Humans ; Incisor ; diagnostic imaging ; Maxilla ; Orthodontics ; methods ; Tooth Apex ; diagnostic imaging ; Tooth Crown ; diagnostic imaging ; Tooth Root ; diagnostic imaging ; Tooth, Impacted ; diagnostic imaging ; therapy ; Treatment Outcome

Alveolar Bone Loss ; Dental Implants ; Humans ; Peri-Implantitis ; epidemiology ; prevention & control ; therapy ; Risk Factors

This study was designed to assess the effectiveness of a modified silk ligature twisted with wire for inducing advanced periodontitis. Periodontitis was induced in five premolars and one molar of 20 healthy dogs over a 60-day period. The dogs were divided into four groups according to the ligature-inducing materials used: soft moistened food only, wire ligature (WL), silk ligature (SL) and twisted ligature with silk and wire (SWL). Periodontal indices were recorded, and dental radiographs were taken before and after 60 days of ligation. The ligatures were checked daily and the day the ligature fell out was noted. The period during which the ligatures were maintained was significantly shorter for the SL group compared to the SWL group (p < 0.05). Results of the clinical examination showed that almost all periodontal status parameters including the plaque index, gingival index, clinical attachment level, and bleeding on probing were significantly exacerbated in the SWL group compared to the other groups (p < 0.05). Radiographic evaluation demonstrated that alveolar bone levels were significantly lower in the SWL group than the other groups on day 60 (p < 0.05). These results suggested that experimental periodontitis induced by SWL could be an effective method for investigating periodontitis in canine models.
Alveolar Bone Loss/veterinary ; Analgesics, Opioid/therapeutic use ; Animals ; Dog Diseases/*pathology ; Dogs ; Ligation/instrumentation/methods/*veterinary ; Materials Testing/veterinary ; Pain/drug therapy/veterinary ; Periodontitis/pathology/*veterinary ; Tramadol/therapeutic use

Alveolar Bone Loss ; etiology ; therapy ; Alveolar Ridge Augmentation ; Dental Implantation, Endosseous ; Dental Prosthesis, Implant-Supported ; Guided Tissue Regeneration, Periodontal ; Humans ; Periodontal Diseases ; complications

BACKGROUNDCurrently, the most commonly used treatment methods for repairing alveolar furcation defects are periodontal guided tissue regeneration (GTR) and bone grafting. The objective of this study was to investigate the effects of simvastatin/methylcellulose gel on bone regeneration in alveolar defects in miniature pigs.

METHODSAlveolar defects were produced in 32 teeth (the third and fourth premolars) of 4 miniature pigs. The 32 experimental teeth were divided into 5 groups comprising control (C) and treatment (T) teeth: (1) empty defects without gel (group C0, n = 4); (2) defects injected with methylcellulose gel (group C1, n = 4); (3) defects injected with 0.5 mg/50 µl simvastatin/methylcellulose gel (group T1, n = 8); (4) defects injected with 1.5 mg/50 µl simvastatin/methylcellulose gel (group T2, n = 8); and (5) defects injected with 2.2 mg/50 µl simvastatin/methylcellulose gel (group T3, n = 8). Every week after surgery, the furcation sites were injected once with gel. At the eighth week after surgery, the 4 pigs were sacrificed and underwent macroscopic observation, descriptive histologic examination, and regenerate bone quantitative histologic examination.

RESULTSAt 8 weeks after surgery, the defect sites in the treatment groups were completely filled in with new bone and fibrous tissue. There was little new bone in the C0 and C1 groups, and only a small number of osteoblasts and proliferative vessels could be seen on microscopic examination.

CONCLUSIONSMiniature pigs are an ideal experimental animal for establishing a model of alveolar defects using a surgical method. Local application of simvastatin/methylcellulose gel can stimulate the regeneration of alveolar bone in furcation defect sites, because it promotes the proliferation of osteoblasts. The best dose of simvastatin gel to stimulate bone regeneration is 0.5 mg.

Alveolar Bone Loss ; drug therapy ; surgery ; Animals ; Bone Regeneration ; drug effects ; Guided Tissue Regeneration, Periodontal ; methods ; Simvastatin ; therapeutic use ; Swine ; Swine, Miniature

Adult ; Alveolar Bone Loss ; therapy ; Blood Glucose ; metabolism ; Chronic Periodontitis ; blood ; complications ; diagnostic imaging ; therapy ; Dental Scaling ; Diabetes Mellitus, Type 1 ; blood ; complications ; drug therapy ; Diabetes Mellitus, Type 2 ; blood ; complications ; drug therapy ; Humans ; Hypoglycemic Agents ; therapeutic use ; Insulin ; therapeutic use ; Male ; Metformin ; therapeutic use ; Middle Aged ; Patient Education as Topic ; Periodontal Index ; Radiography, Panoramic ; Root Planing ; Sulfonylurea Compounds ; therapeutic use

BACKGROUNDPlatelet-rich plasma (PRP) is a kind of natural source of autologous growth factors, and has been used successfully in medical community. However, the effect of PRP in periodontal regeneration is not clear yet. This study was designed to evaluate the effectiveness of PRP as an adjunct to bovine porous bone mineral (BPBM) graft in the treatment of human intrabony defects.

METHODSSeventeen intrabony defects in 10 periodontitis patients were randomly treated either with PRP and BPBM (test group, n = 9) or with BPBM alone (control group, n = 8). Clinical parameters were evaluated including changes in probing depth, relative attachment level (measured by Florida Probe and a stent), and bone probing level between baseline and 1 year postoperatively. Standardized periapical radiographs of each defect were taken at baseline, 2 weeks, and 1 year postoperatively, and analyzed by digital subtraction radiography (DSR).

RESULTSBoth treatment modalities resulted in significant attachment gain, reduction of probing depth, and bone probing level at 1-year post-surgery compared to baseline. The test group exhibited statistically significant improvement compared to the control sites in probing depth reduction: (4.78 +/- 0.95) mm versus (3.48 +/- 0.41) mm (P < 0.01); clinical attachment gain: (4.52 +/- 1.14) mm versus (2.85 +/- 0.80) mm (P < 0.01); bone probing reduction: (4.56 +/- 1.04) mm versus (2.88 +/- 0.79) mm (P < 0.01); and defect bone fill: (73.41 +/- 14.78)% versus (47.32 +/- 11.47)% (P < 0.01). DSR analysis of baseline and 1 year postoperatively also showed greater radiographic gains in alveolar bone mass in the test group than in the control group: gray increase (580 +/- 50) grays versus (220 +/- 32) grays (P = 0.0001); area with increased gray were (5.21 +/- 1.25) mm(2) versus (3.02 +/- 1.22) mm(2) (P = 0.0001).

CONCLUSIONSThe treatment with a combination of PRP and BPBM led to a significantly favorable clinical improvement in periodontal intrabony defects compared to using BPBM alone. Further studies are necessary to assess the long-term effectiveness of PRP, and a larger sample size is needed.

Adult ; Alveolar Bone Loss ; diagnostic imaging ; surgery ; Animals ; Blood Platelets ; physiology ; Bone Regeneration ; drug effects ; Bone Substitutes ; therapeutic use ; Bone Transplantation ; methods ; Cattle ; Combined Modality Therapy ; Female ; Follow-Up Studies ; Growth Substances ; therapeutic use ; Guided Tissue Regeneration, Periodontal ; methods ; Humans ; Male ; Middle Aged ; Minerals ; therapeutic use ; Plasma ; chemistry ; cytology ; Platelet Transfusion ; Radiography ; Transplantation, Heterologous ; Treatment Outcome

OBJECTIVE: To explore the effect of astragalus polysaccharides-chitosan/polylactic acid (AP-C/PLA) scaffolds and bone marrow stem cells (BMSCs) on periodontal regeneration of experimentally horizontal periodontal defects in dogs. METHODS: Dog BMSCs were isolated from the bone marrow and then cultured in a conditioned medium to be induced for osteogenesis. The expressions of Type I collagen and alkaline phosphatase (ALP) were examined by immunohistochemistry and histochemistry in the induced BMSCs, respectively. The BMSCs were harvested and implanted with astragalus polysaccharides-chitosan/polylactic acid (AP-C/PLA) and chitosan/polylactic acid (C/PLA) scaffolds. Horizontal alveolar bone defects (5 mm depth, 2 mm width) were produced surgically in the buccal side of the mandibular premolar 3 and 4 of the 10 dogs. The defects were randomly repaired with a cell-scaffold construction (10 teeth per group): root planning only (surgical control), AP-C/PLA with a conditioned medium (medium control), C/PLA with BMSCs (scaffolds control), and AP-C/PLA with BMSCs (experimental group) . The dogs were killed at 4 weeks and 8 weeks after the surgery, and block sections of the defects were collected for the histologic and histometric analysis. RESULTS: BMSCs induced in vitro exhibited an osteogenic phenotype with expressing Type I collagen and ALP histologically. The bone nodule structure was observed in the experimental group 4 weeks postsurgically. The engineered bone became more mature,similar to the native bone 8 weeks postsurgically. The amount of new bone regeneration and the rate of new bone filling to the defect height of the experimental group were significantly different from those of the surgical control, medium control, and scaffolds control [(2.90+/-0.41) mm vs (0.83+/-0.30) mm, (1.46+/-0.55) mm, (2.67+/-0.26) mm; 57.46% vs 15.68 %, 30.13%, 51.87%)] (P<0.01, P<0.01, P<0.05). CONCLUSION Astragalus polysaccharides can promote the new bone formation on the periodontal defects. The technology of tissue engineering with AP-C/PLA scaffolds and induced BMSCs may contribute to the periodontal regeneration.
Alveolar Bone Loss ; therapy ; Animals ; Astragalus propinquus ; Bone Marrow Cells ; cytology ; Bone Regeneration ; physiology ; Chitosan ; pharmacology ; Dogs ; Drugs, Chinese Herbal ; pharmacology ; Lactic Acid ; pharmacology ; Osteogenesis ; Polyesters ; Polymers ; pharmacology ; Stem Cells ; cytology ; Tissue Engineering