Clinical analysis on the root fracture of the maxillary first molar / 华西口腔医学杂志

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 (@*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.

Periodontal treatment of furcation involvement at the mandibular first molar with a follow-up of 27 years / 华西口腔医学杂志

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.

Efficacy of periodontal endoscope-assisted non-surgical treatment for severe and generalized periodontitis / 华西口腔医学杂志

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 (P6 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 / 华西口腔医学杂志

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 (P0.05), 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.

Different expression of cytokines induced by Actinobacillus actinomycetemcomitans lipopolysaccharide in monocytes/macrophages from different organs of rabbits / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of cytokines induced by Actinobacillus actinomycetemcomitans lipopolysaccharide (Aa-LPS) in monocytes/macrophages from different organs of rabbits.</p><p><b>METHODS</b>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-1β, IL-8 mRNA and protein were determined by real-time PCR and enzyme-linked immunosorbent assay respectively.</p><p><b>RESULTS</b>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-1β, 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.</p><p><b>CONCLUSIONS</b>Aa-LPS influenced the expression of cytokines in monocytes/macrophages from different organs of rabbits.</p>

Expression of triggering receptors expressed on myeloid-1 in innate response to Porphyromonas gingivalis in macrophages / 中华口腔医学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSIONS</b>TREM-1 enhanced innate immune response to Pg in macrophages, which may facilitate periodontitis development.</p>

Effects of Porphyromonas gingivalis lipopolysaccharide on apoptotic genes in foam cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) on apoptotic genes in foam cells.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>Pg-LPS affected apoptotic gene transcription during and after foam cells formation and enhanced cell apoptosis.</p>

Effect of cryopreservation of bone marrow stromal cells on periodontal tissue regeneration / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of cryopreservation on bone marrow stromal cells' (BMSC) capability of enhancing periodontal regeneration.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>Cryopreservation had no significant negative effects on BMSC capability of enhancing periodontal regeneration.</p>