Comparative Study of Two Ways to Measure Root Trunk Length to Assess the Possibility of Crown Lengthening in Molars: Measuring Parallel to the Root Surface vs Parallel to the Tooth Axis

The aim of this study was to compare root trunk measurements taken parallel to the tooth axis (TA) to those taken parallel to the root surface (RS) in order to assess the decision-making implications of each method on crown-lengthening surgery. A total of 672 root trunks were measured via CBCT in two planes: TA and RS. The possibility of performing crown lengthening in each clinical situation based on the distance from the cementoenamel junction (CEJ) to the crestal bone (CB) after ostectomy (CEJ-CB) was judged and compared between groups. When RS was used as a reference point, the proportions of cases that judged crown lengthening to be possible were 83.63%, 59.08%, and 39.18% for CEJ-CB values of 4, 5, and 6 mm, respectively. When TA was used instead, those proportions decreased by 3.87% to 7.29%. The lingual root trunk of the lower first molar (LFL) with a CEJ-CB of 4 to 5 mm emerged as the most problematic area; here, the difference between reference planes occurred with one out of every six teeth. Within the limits of this study, utilizing TA for surgical crown-lengthening treatment planning is not ideal because it may lead to extraction of many savable teeth.

Association between periodontitis and spontaneous abortion: A case-control study.

BACKGROUND: Spontaneous abortion, or miscarriage, is a complication of pregnancy which can severely affect women both physically and psychologically. We investigated the associations of periodontitis and periodontopathic bacteria with spontaneous abortion. METHODS: We conducted a matched case-control study in two tertiary hospitals in Khon Kaen, Thailand. Cases were 85 women with spontaneous abortion at <20 weeks of gestation matched to 85 controls on age, gestational age, and hospital. Full-mouth periodontal examinations were performed. Periodontitis was defined as at least one site with probing depth ≥5 mm and clinical attachment level ≥2 mm at the same site. Subgingival plaque samples were collected to determine the levels of Porphyromonas gingivalis, Tannerella forsythia, and Fusobacterium nucleatum using real time polymerase chain reaction. RESULTS: The cases were significantly more likely to have periodontitis (50.6%) than the controls (21.2%; P = 0.007). Conditional logistic regression revealed a crude odds ratio (OR) of 4.1 for the association between periodontitis and spontaneous abortion (95% confidence interval [CI] = 1.9-8.9, P = 0.001). The OR decreased, but was still significant, after controlling for previous miscarriage (OR = 3.3, 95% CI = 1.4-7.8, P = 0.006). There was no significant association between the levels of periodontopathic bacteria and spontaneous abortion. Increased levels of P. gingivalis and F. nucleatum were associated with periodontitis in both case and control groups. Association between increased T. forsythia levels and periodontitis was observed only in the case women. CONCLUSIONS: Periodontitis was more common in women with spontaneous abortions as compared with matched controls. Levels of periodontopathic bacteria was not associated with spontaneous abortion in this population.

Induction of toll-like receptor expression by Porphyromonas gingivalis.

BACKGROUND: Toll-like receptors (TLRs) play pivotal roles in host immune responses and have been suggested to be involved in the development of many infectious diseases. In this study, the mRNA expression levels of TLR2, TLR4, and TLR9 and their relationship with periodontopathic bacteria in periodontal tissue are examined. Furthermore, the mechanism of TLR induction by Porphyromonas gingivalis is investigated in human gingival fibroblasts (HGFs). METHODS: Gingival tissue and subgingival plaque samples were collected from 19 patients with chronic periodontitis (CP) and 16 control individuals without periodontitis. Gene expression levels in the tissues and in HGFs were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The numbers of periodontopathic bacteria were determined by quantitative real-time PCR. RESULTS: The expression levels of TLR2 and TLR9 were significantly higher in the tissues of patients with CP compared to the tissues of control individuals. The mRNA levels of TLR2 and TLR9, but not TLR4, were positively correlated with the number of P. gingivalis in subgingival plaque. P. gingivalis sonicated extract, P. gingivalis lipopolysaccharide, P. gingivalis DNA, and tumor necrosis factor-α(TNF-α) could significantly upregulate the mRNA expression of TLR2 in HGFs. Furthermore, P. gingivalis-mediated TLR2 expression was suppressed by TNF-α antibody. CONCLUSIONS: This study suggests that P. gingivalis infection induces TLR2 and TLR9 upregulation in patients with CP. P. gingivalis-induced TLR2 expression in HGFs is partially dependent on TNF-α and may lead to sensitization of HGFs to bacterial components encountered in the periodontal microenvironment.

Trefoil factors in saliva and gingival tissues of patients with chronic periodontitis.

BACKGROUND: Trefoil factors (TFFs) are secreted molecules that are involved in cytoprotection against tissue damage and the immune response. TFFs have been detected in saliva and oral tissues, but their clinical significance has never been investigated in patients with chronic periodontitis. The objective of this study is to determine whether TFF expression in saliva and gingival tissues is associated with periodontal pathology. METHODS: Saliva and gingival tissue samples were collected from 25 non-periodontitis individuals and 25 patients with chronic periodontitis (CP). Enzyme-linked immunosorbent assay and immunohistochemical methods were used to evaluate the expression of TFFs (TFF1, TFF2, and TFF3) in saliva and gingival tissues, respectively. Periodontopathic bacteria were quantified by real-time polymerase chain reaction. RESULTS: Reduced salivary TFF1 and TFF3 concentrations were observed in patients with CP (P = 0.003 and P <0.001, respectively). Decreased TFF3 expression in gingival tissues of patients with CP was demonstrated (P = 0.041). Levels of salivary TFF3 concentrations were negatively correlated with periodontal pathology and number of Porphyromonas gingivalis and Tannerella forsythia (formerly known as Bacteroides forsythus). CONCLUSIONS: Altered expression of TFFs in saliva and gingival tissues was detected in patients with CP. The results suggest that TFF3 may be involved in the pathogenesis of periodontal disease.

RANKL upregulation associated with periodontitis and Porphyromonas gingivalis.

BACKGROUND: Receptor activator of nuclear factor-kappa B (NF-kappaB) ligand (RANKL) and osteoprotegerin (OPG) are critical for homeostatic control of osteoclast activity, suggesting their vital roles in the progression of bone loss in periodontitis. In this study, the expression of RANKL and OPG mRNA and the relationship between these factors and periodontopathic bacteria in periodontal tissue were studied. METHODS: Gingival tissue and subgingival plaque samples were collected from 15 patients with chronic periodontitis and 15 periodontally healthy subjects. RNA was extracted from the tissue and subjected to reverse transcription-polymerase chain reaction (RT-PCR) using primers specific for RANKL or OPG. Beta-actin was amplified as a control to ensure equal loading. The intensity of RT-PCR products was analyzed by a densitometer in proportion to the intensity of beta-actin. The numbers of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were determined by quantitative real-time PCR. RESULTS: Our results showed increased levels of RANKL mRNA in chronic periodontitis tissues. The RANKL/OPG expression ratio was significantly higher in the periodontitis group compared to the healthy control group (P = 0.001). Interestingly, the expression of RANKL (r = 0.64; P <0.001), but not OPG (r = -0.24; P = 0.20), was significantly correlated with increased numbers of P. gingivalis. A. actinomycetemcomitans was detected in only 6.7% of all sites. CONCLUSIONS: Chronic periodontitis was associated with RANKL mRNA upregulation and increased RANKL/OPG mRNA expression ratio. In addition, our data showed for the first time to our knowledge an association between upregulated RANKL levels and the number of P. gingivalis in clinically obtained periodontal tissues.