[A novel periodontal endoscopy-aided non-incisional periodontal regeneration technique：a case series study].

PURPOSE: To investigate the effect of endoscopy-aided non-incisional periodontal regeneration technique (NIT) in the treatment of alveolar bone angular resorption. METHODS: Thirteen patients with severe periodontitis(13 diseased teeth) were selected. All patients had alveolar bone angular resorption on adjacent surface. The patients received NIT treatment 6 weeks after periodontal primary therapy. The visualization of subgingival environment was acquired by the periodontal endoscopy. Following the removal of the subgingival plaque, calculus and intra-bony granulation tissue, bone grafting materials were placed into the intra-bony defects with the assistance of a delicate gingival protector. No flap was elevated and no sutures were applied. Probing depth (PD), gingival recession (GR), clinical attachment level (CAL), as well as radiographic parameters were evaluated at baseline and 2 years after treatment. SPSS 22.0 software package was used for data analysis. RESULTS: At 2-years follow-up, an average CAL gain of (3.65±2.10) mm (P＜0.001), PD reduction of (4.42±1.66) mm (P＜0.001), and minimal increase in GR of (0.38±0.87) mm (P=0.25) were observed. Alveolar bone was significantly improved at 2-years follow-up on radiographs (P＜0.001). CONCLUSIONS: For angular resorption site of alveolar bone, NIT treatment can obtain good periodontal regeneration results without flap inversion.

Periodontal-orthodontic interdisciplinary management of a "periodontally hopeless" maxillary central incisor with severe mobility: A case report and review of literature.

BACKGROUND: Treating periodontally hopeless teeth with advanced bone resorption and severe tooth mobility is a great challenge for both orthodontists and periodontists. Biofilm-induced periodontal inflammation and occlusal trauma-related inflammation may synergistically aggravate tooth mobility. This case report illustrates that even periodontally hopeless teeth can be saved and have long-term stability with comprehensive periodontal treatment to control periodontal inflammation and promote periodontal bone regeneration and intricate orthodontic mechanical control to correct cross bite and occlusal trauma. CASE SUMMARY: A 27-year-old female patient whose chief complaint was severe tooth mobility and discomfort of the maxillary incisor was diagnosed with severe aggressive periodontitis by clinical and radiographic examinations. To reduce tooth mobility and establish stable occlusion, we combined orthodontic treatment with periodontal therapy to preserve the tooth. Orthodontic treatment was performed after basic periodontal therapy and periodontal surgery. The loosened upper right central incisor was successfully retained, and the periodontal tissue remained stable during follow-up. CONCLUSION: Teeth with severe mobility and bone loss can be saved through interdisciplinary treatment when periodontal inflammation is strictly controlled.

Periodontal treatment of furcation involvement at the mandibular first molar with a follow-up of 27 years.

Due to the complicated anatomical structures in the furcation area of multirooted mandibular first molars, dental hygiene is greatly compromised once the furcation is involved in the periodontitis, leading to the unfavorable prognosis of teeth with furcation involvement. A patient came to a dental office with the chief complaint of "mobile mandibular posterior tooth" 27 years ago. The periapical film showed alveolar bone resorption at the root furcation of the right mandibular first molar. Flap surgery and fine supportive therapy were conducted. The patient was diagnosed with "furcation involvement Class Ⅲ" during a revisit three years ago. Satisfactory and healthy periodontal statuses were observed 2, 9, 24, and 33 months after the periodontal flap surgery plus tunneling procedures. A follow-up of 27 years in the present case demonstrated that a favorable prognosis of furcation involvement can be achieved after adequate periodontal treatment.

Clinical analysis on the root fracture of the maxillary first molar.

OBJECTIVES: This study aimed to investigate the common types and directions of root fractures of the maxillary first molar and the influence of root canal treatment on the prevalent sites of root fractures. METHODS: A total of 274 maxillary first molars with root fractures diagnosed via cone beam computed tomography were included. The root fractures of nonendodontically and endodontically treated teeth were identified to be spontaneous and secondary root fractures, respectively. The sites, types, and directions of spontaneous and secondary root fractures were determined. RESULTS: Among the spontaneous root fractures, the proportion of palatal root fractures (56.1%) was higher than those of mesial buccal root fractures (36.1%) and distal buccal root fractures (7.8%). Among the secondary root fractures, the proportion of mesial buccal root fractures (52.7%) was higher than those of palatal root fractures (36.5%) and distal buccal root fractures (10.8%). The distribution of predominant fracture sites was statistically significant (P<0.05), and vertical root fracture was the most common type. Palatal and buccal roots were commonly fractured at the mesiodistal and buccal-palatal directions, respectively. CONCLUSIONS: This study provided an epidemiological basis for the clinical features of root fractures of the maxillary first molar. During the dia-gnosis and treatment of the maxillary first molar, the possibility of palatal root fractures should be considered. The occurrence of mesial buccal root fractures may be related to root canal treatment. Therefore, the risk of mesial buccal root fractures caused by iatrogenic factors should be minimized.

[Clinical effects of scaling and root planing with an adjunctive periodontal endoscope for residual pockets: a randomized controlled clinical study].

OBJECTIVE: To evaluate the efficacy of scaling and root planing (SRP) with a periodontal endoscope in the treatment of residual pockets in patients with periodontitis after initial periodontal therapy. METHODS: Patients with residual pockets [probing depth (PD)≥5 mm] were included and randomly assigned to the endoscope group (SRP with a periodontal endoscope) or SRP group (SRP alone). The PD, attachment loss (AL), and bleeding on probing (BOP) of residual pockets were recorded before treatment and at 3 and 6 months after treatment. Data were analyzed with SPSS 20.0 software. RESULTS: Compared with the baseline values, the percentage of PD≥5 mm sites, PD, AL, and BOP (+)% in the endoscope group and SRP group at 3 and 6 months after treatment decreased (P<0.05). Compared with the values at 3 months after treatment, the percentage of PD≥5 mm sites, PD, AL, and BOP (+)% at 3 and 6 months after treatment decreased in the endoscope group (P<0.05), whereas no statistical difference in these values was observed in the SRP group (P>0.05). Compared with those in the SRP group, the percentage of PD≥5 mm sites and PD at 3 and 6 months after treatment and AL and BOP (+)% at 6 months after treatment in the endoscope group decreased (P<0.05). CONCLUSIONS: SRP with a periodontal endoscope shows a better effect in improving the PD, AL, and BOP of residual pockets (PD≥5 mm) in patients with periodontitis after initial periodontal therapy and has advantages in improving the long-term curative effect of this therapy.

[Efficacy of periodontal endoscope-assisted non-surgical treatment for severe and generalized periodontitis].

OBJECTIVE: To evaluate the effectiveness of periodontal endoscope as an adjuvant therapy for the non-surgical periodontal treatment of patients with severe and generalized periodontitis. METHODS: Patients (n=13) were divided into three groups: patients treated with conventional subgingival scaling and root planing (SRP) (n=7, 408 sites) (group A), SRP using periodontal endoscope (n=4, 188 sites) (group B) or SRP with periodontal endoscope 3 months after initial SRP (n=2, 142 sites) (group C). Two subgroups were divided into 2 subgroups according to PD at the baseline: 46 mm as subgroup 2. Probing depth (PD), attachment loss (AL), gingival recession (GR) and bleeding on probing (BOP) were recorded. RESULTS: The results of 3 months after treatment showed all PD, AL, and GR values in group A1 were less than those in group B1 (P<0.05), but no significant difference in BOP was found between the two groups. The decrease in PD, BOP in group B2 was more obvious than those in group A2 (P<0.000 1), and the GR values in group B2 were more than those in group A2 (P<0.000 1). But the improvement of AL showed no statistical difference between the two groups (P=0.296 8). In group C1, no significant difference in PD, AL, and GR was observed after endoscopy-assisted therapy, but it was more effective for BOP (P<0.000 1). In group C2, the improvement in PD and AL was significantly different from the improvement in SRP alone (P=0.000 5, P=0.000 2) and was accompanied by more GR (P=0.000 5). CONCLUSIONS: In non-surgical treatment of severe and generalized periodontitis, SRP can achieve good therapeutic effect on sites with 46 mm, the application of periodontal endoscopy can increase the effect, reducing PD and GR, which may be an effective supplement to the current non-surgical periodontal treatment.

[Accuracy of paralleling technique in measuring the depth of approximal infrabony pocket].

OBJECTIVE: To assess the accuracy of paralleling technique in measuring the depth of approximal infrabony pocket after periodontal flap surgery by comparing the measured and actual depths. METHODS: The study population included 26 patients with infrabony defects who had undergone periodontal flap surgery, bone graft surgery, and guided tissue regene-ration. The measured and actual depths of approximal infrabony pocket after periodontal flap surgery were compared. The 26 infrabony defects were categorized into the following groups according to tooth position: anterior teeth, premolar, and molar groups, and according to type of infrabony pocket: one-walled, two-walled, and three-walled infrabony pocket groups. Paired t-test was used to detect the difference between the two values. RESULTS: Depth measurements of the approximal infrabony pocket depth of the anterior teeth and premolar were not significantly different (P>0.05), whereas those of the molar group were significantly different (P<0.05). In addition, depth measurements in one-walled and two-walled infrabony pocket groups showed no significant differences (P>0.05), whereas those in the three-walled infrabony pocket group were significantly different (P<0.05). CONCLUSIONS: Paral-leling technique can accurately measure the depth of approximal infrabony pockets of anterior teeth and premolar teeth that are one- or two-walled. However, this method cannot accurately measure the approximal infrabony pockets of molar teeth and three-walled infrabony pockets as indicated by significant differences in their depth measurements.

[Hyperlipidemia inhibited inflammatory response to Porphyromonas gingivalis in apolipoprotein E knockout mice].

PURPOSE: To investigate the effect and mechanism of hyperlipidemia on inflammatory response to Porphyromonas gingivalis(P. gingivalis) in apolipoprotein E knock out(ApoE-/-) mice. METHODS: Long term hyperlipidemia model was established in ApoE-/- mice, and viable P. gingivalis were injected into peritoneal cavity to make peritonitis model. Bacteria clearance capability was detected by serial dilution, production of pro-inflammatory cytokine interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) in serum was measured by ELISA, and IL-6 as well as MCP-1 transcription in peritoneal cells was determined by real time PCR. The data was analyzed with SPSS13.0 software package. RESULTS: Hyperlipidemia disrupted P. gingivalis clearance capability in ApoE-/- mice, accompanied by inhibited IL-6 and MCP-1 transcription in peritoneal cells and decreased IL-6 and MCP-1 release into blood. CONCLUSIONS: Hyperlipidemia disrupts inflammatory response to P. gingivalis, leading to decreased bacteria clearance, which may affect periodontitis progression.

[Expression of triggering receptors expressed on myeloid-1 in innate response to Porphyromonas gingivalis in macrophages].

OBJECTIVE: To investigate the role of triggering receptors expressed on myeloid-1(TREM-1) in innate response to Porphyromonas gingivalis(Pg) in mice macrophages and its potential role in periodontitis development. METHODS: Peritoneal macrophages from mice were harvested, separated and cultured, then challenged with viable Pg. Transcription and protein expression in macrophages were assessed with real time PCR and flow cytometry respectively.LP-17 peptide (10, 100 and 1000 µg/L) was utilized to block TREM-1, and tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were detected by enzyme linked absorbent analysis. RESULTS: At 2 h after Pg challenge, transcription of TREM-1 was significantly up-regulated after Pg challenge[(7.99 ± 1.11) fold vs blank]. At 24 h after bacteria infection, increased TREM-1 expression was demonstrated by flow cytometry, with mean fluorescent intensity increasing from (7.05 ± 1.85) in blank group to (13.17 ± 2.33) in experimental group. Proinflammatory cytokine (TNF-α and IL-6) production was significantly decreased after blocking TREM-1 by LP-17 peptide(100 and 1000 µg/L). CONCLUSIONS: TREM-1 enhanced innate immune response to Pg in macrophages, which may facilitate periodontitis development.

[Different expression of cytokines induced by Actinobacillus actinomycetemcomitans lipopolysaccharide in monocytes/macrophages from different organs of rabbits].

OBJECTIVE: To investigate the expression of cytokines induced by Actinobacillus actinomycetemcomitans lipopolysaccharide (Aa-LPS) in monocytes/macrophages from different organs of rabbits. METHODS: The peripheral mononuclear cells (Mo), alveolar macrophages (AM), peritoneal macrophages (PM) and Kupffer cells (KC) from five New Zealand rabbits were isolated respectively. Then the cells from different organs were stimulated with Escherichia coli (Ec)-LPS or Aa-LPS at the dose of 1 mg/L. After culture for 24 hours, the expression of tumor necrosis factor-α (TNF-α), interleukin (IL)6, IL-1ß, IL-8 mRNA and protein were determined by real-time PCR and enzyme-linked immunosorbent assay respectively. RESULTS: The monocytes/macrophages challenged by Ec-LPS or Aa-LPS expressed more cytokines both in mRNA and protein levels compared with the controls (P < 0.05). Among them, AM displayed the highest respond when encount with Aa-LPS, with the TNF-α, IL-6, IL-1ß, IL-8 mRNA relative levels were (0.4719 ± 0.0171), (2.7895 ± 0.0669), (5.1527 ± 0.1190), (3.6785 ± 0.1836) and the proteins concentrations were (82.2 ± 5.4), (40.2 ± 2.0), (50 308.3 ± 445.0), (35 305.3 ± 1480.9) ng/L respectively. And the inducibility of Aa-LPS was stronger than that of Ec-LPS (P < 0.05). Meanwhile the cells from different organs showed discrepant response when exposed to Aa-LPS (P < 0.05). The results showed their abilities to secrete cytokines were in the sequence of AM > Mo > KC > PM. CONCLUSIONS: Aa-LPS influenced the expression of cytokines in monocytes/macrophages from different organs of rabbits.

[Effects of Porphyromonas gingivalis lipopolysaccharide on apoptotic genes in foam cells].

OBJECTIVE: To investigate the effects of Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) on apoptotic genes in foam cells. METHODS: Macrophages from THP-1 monocytes and foam cells from macrophages by oxLDL inducement were treated with oxidized low density lipoprotein (oxLDL) or oxLDL+ Pg-LPS. Cell apoptosis was detected by acridine orange-ethidium bromide (AO-EB) staining. Eleven atherosclerotic related apoptotic genes were examined with polymerase chain reaction (PCR) array, and apoptotic gene p53, c-Myc and caspase-3 were evaluated with real-time PCR. RESULTS: Pg-LPS enhanced cell apoptosis rate during and after foam cells formation [(5.47+/-0.93)% vs. (7.50+/-0.54)%]. PCR array demonstrated that it increased B-cell CLL-lymphoma 2 (BCL2) related protein A1 (BCL2A1) transcription during foam cells formation (>2 fold), and promoted BCL2 and BCL2A1 transcription after foam cells formation (>2 fold). It promoted p53 and caspase-3 transcription level (4.50x10(-3)+/-4.02x10(-4) vs. 5.30x10(-2)+/-4.58x10(-3)), whereas inhibited c-Myc transcription level (1.53x10(-2)+/-5.77x10(-4)) during foam cells formation. It promoted caspase-3 transcription (6.00x10(-2)+/-6.08x10(-3)), and inhibited p53 transcription (4.23x10(-3)+/-5.85x10(-4)) after foam cells formation. CONCLUSIONS: Pg-LPS affected apoptotic gene transcription during and after foam cells formation and enhanced cell apoptosis.

[Changes in cytokine levels during foam cells formation induced by oxidized low density lipoprotein stimulation].

AIM: To investigate the alteration in levels of TNF-α, IL-1ß, IL-10, IL-12 p40 and IL-18 during foam cells formation. METHODS: human THP-1 monocytes-originated macrophages were cultured in RPMI1640 culture medium without serum for 24 h, and then were stimulated with oxidized low density lipoprotein (oxLDL) for 48 h. Foam cells formation was evaluated by oil red O staining and chemical method. Levels of TNF-α and IL-1ß in the supernatants during foam cells formation were detected by ELISA. The transcription of IL-1ß, IL-10, IL-12 p40 and IL-18 mRNAs was evaluated by real-time PCR. RESULTS: 81.07% macrophages were in G0;-G1; stage when cultured with raw RPMI1640 medium. Lipid could be obviously detected in macrophages induced by oxLDL for 48 h, and the rate of cholesterol ester to total cholesterol was over 50%. Levels of TNF-α in the supernatants reached the highest level at 12 h, and the lowest level at 48 h, IL-1ß remained at a high level at all time point. Transcription of IL-1ß, IL-10 and IL-12 p40 mRNA was enhanced at 2 h after oxLDL stimulation (P < 0.01), and transcription of IL-1ß, IL-10 and IL-18 increased significantly at 50 h compared to 2 h, whereas IL-12 decreased significantly at 50 h compared to 2 h (P < 0.01). CONCLUSION: Cytokine levels showed an early acute inflammatory and a lately chronic anti-inflammatory process in oxLDL induced macrophages.

[Effect of cryopreservation of bone marrow stromal cells on periodontal tissue regeneration].

OBJECTIVE: To investigate the influence of cryopreservation on bone marrow stromal cells' (BMSC) capability of enhancing periodontal regeneration. METHODS: Twenty-six artificial periodontal defects were established in 5 Beagle dogs and divided into 3 groups at random. Only collagen membrane, the complex of cryopreserved and un-cryopreserved BMSC and collagen scaffold were transplanted in the blank control group, cryopreserved and un-cryopreserved groups respectively. The periodontal regeneration was observed 8 weeks after transplantation. RESULTS: The percentage of periodontal regeneration in cryopreserved and un-cryopreserved groups was significantly greater than that of the blank control group (P < 0.05), but no statistical difference was found between cryopreserved and un-cryopreserved groups. CONCLUSIONS: Cryopreservation had no significant negative effects on BMSC capability of enhancing periodontal regeneration.