Early wound healing at 1 week postoperatively in periodontal tissue regeneration therapy: enamel matrix derivative versus recombinant human fibroblast growth factor.

PURPOSE: Recombinant human fibroblast growth factor-2 (rhFGF-2) has demonstrated positive effects on wound healing at 2 weeks after periodontal surgery relative to enamel matrix derivative (EMD). However, the effects at earlier postoperative stages have not been reported. This retrospective study compared the early wound healing outcomes 1 week after surgery using the modified papilla preservation technique (mPPT) with either EMD or rhFGF-2 therapy. METHODS: We compiled a list of all mPPT sites treated with EMD or rhFGF-2 during the survey period (September 2011 to March 2022). Early wound healing was assessed using the early wound healing score (EHS) and the modified early wound healing index (mEHI). Inter-rater reliability for the EHS and mEHI was established using intraclass correlation coefficients. Factors influencing mPPT were identified by analyzing the correlation coefficients between the EHS items, mEHI items, and potential influencing factors. After adjusting for factors impacting EHS, mEHI, and mPPT, we compared the EHS and mEHI between EMD and rhFGF-2 groups. RESULTS: In total, 72 sites were evaluated. The scores for incision line, step, and dehiscence were significantly higher in those receiving rhFGF-2 (n=42) compared to those treated with EMD (n=30). The EHS item scores did not differ significantly between groups. Among patients aged ≥50 years, but not those <50 years, significantly higher step and dehiscence scores were found in the rhFGF-2 group than the EMD group (P<0.01). Additionally, for patients exhibiting a clinical attachment level (CAL) ≥8 mm, the step score was significantly higher in the rhFGF-2 group than in the EMD group (P<0.05), but this trend was not reflected in those with a CAL <8 mm. CONCLUSIONS: In this study, early wound closure at mPPT sites was more effectively achieved with rhFGF-2 than with EMD. Nevertheless, biochemical assessments are required to compare the re-epithelialization effects of these therapies.

Multimodal inhibitory effect of matcha on Porphyromonas gingivalis.

Porphyromonas gingivalis has been associated with progression of periodontitis, characterized by inflammation and destruction of periodontal tissues. Here, we report that matcha, a product of Camellia sinensis, hampers the adherence and survival of P. gingivalis through multiple tactics. Matcha extract (ME) inhibited the growth not only of P. gingivalis but also of Prevotella nigrescens and Fusobacterium nucleatum, while it did not inhibit growth of nine species of oral streptococci and Aggregatibacter actinomycetemcomitans. ME-mediated P. gingivalis growth inhibition was characterized by both morphological and physiological changes at the bacterial envelope, which were accompanied by nano-particle formation and decreased membrane fluidity/permeability without loss of membrane integrity. ME also triggered autoaggregation of P. gingivalis in a major fimbriae (FimA)-dependent manner. In addition, adherence of P. gingivalis was dramatically inhibited by ME, irrespective of fimbriae. Furthermore, a structure-activity relationship study tested a series of catechins isolated from ME and identified the pyrogallol-type B-ring of catechins as essential for P. gingivalis growth inhibition. In a clinical study to assess the microbiological and therapeutic effects of matcha mouthwash in patients with periodontitis, the P. gingivalis number in saliva was significantly reduced by matcha mouthwash compared to the pre-intervention level. A tendency toward improvement in probing pocket depth was observed in the matcha group, although the difference was not statistically significant. Taken together, we present a proof of concept, based on the multimodal inhibitory effect of matcha against P. gingivalis, and that matcha may have clinical applicability for prevention and treatment of periodontitis. IMPORTANCE: Periodontitis, a multifactorial inflammatory disease of the oral cavity, results in alveolar bone destruction, and is a major cause of tooth loss of humans. In addition, emerging evidence has demonstrated associations between periodontitis and a wide range of other chronic inflammation-driven disorders, including diabetes mellitus, preterm birth, cardiovascular disease, aspiration pneumonia, rheumatoid arthritis, cognitive disorder, and cancer. In the present study, we report that matcha, a product of Camellia sinensis, hampers Porphyromonas gingivalis, a major periodontal pathobiont, in not only a series of in vitro experiments but also a pilot intervention clinical trial of patients with periodontitis, in which matcha mouthwash statistically significantly reduced the P. gingivalis number in saliva, as compared to the pre-intervention level. Taken together, we suggest that matcha may have clinical applicability for prevention and treatment of periodontitis.

Carbonate apatite increases gene expression of osterix and bone morphogenetic protein 2 in the alveolar ridge after socket grafting.

PURPOSE: After tooth extraction, preservation of the alveolar ridge by socket grafting attenuates bone resorption. Runt-related transcription factor 2 (RUNX2) and SP7/Osterix (OSX) are transcription factors playing an important role in osteoblast differentiation. The purpose of this study was to evaluate the effects of carbonate apatite (CO3Ap) on osteoblast-related gene and protein expression after socket grafting. METHODS: Alveolar bone and new bone after CO3Ap grafting were collected at the time of implant placement. Levels of mRNA for RUNX2, SP7/OSX, bone morphogenetic protein 2 (BMP2), BMP7 and platelet derived growth factor B were determined by real-time PCR. Immunostaining was performed using antibodies against RUNX2, SP7/OSX, vimentin and cytokeratin. To evaluate bone resorption rates, cone-beam CT (CBCT) imaging was performed after socket grafting and before implant placement. RESULTS: CBCT imaging showed that the average degree of bone resorption at the CO3Ap graft site was 7.15 ± 3.79%. At the graft sites, levels of SP7/OSX and BMP2 mRNA were significantly increased. Replacement of CO3Ap with osteoid was evident histologically, and in the osteoid osteoblast-like cells were stained for SP7/OSX and vimentin. CONCLUSION: These results show that gene expression of both SP7/OSX and BMP2 can be induced by CO3Ap, suggesting that increased expression of SP7/OSX and vimentin may be involved in the BMP pathway.

Comparison of early wound healing using modified papilla preservation technique between enamel matrix derivative and recombinant human fibroblast growth factor.

PURPOSE: Enamel matrix derivative (EMD) has demonstrated beneficial effects on wound healing following surgery. However, the effects of recombinant human fibroblast growth factor 2 (rhFGF-2) in periodontal regeneration therapy have not been extensively studied. This retrospective study was conducted to compare the wound healing outcomes of the modified papilla preservation technique (mPPT) between EMD and rhFGF-2 therapies. METHODS: A total of 79 sites were evaluated for early wound healing using the modified early wound healing index (mEHI), which included 6 items: incision, fibrin clotting, step, redness, swelling, and dehiscence. A numeric analog scale, along with postoperative images of the 6 mEHI items, was established and used for the evaluations. The inter-rater reliability of the mEHI was assessed via intraclass correlation coefficients (ICCs). After adjusting for factors influencing the mPPT, the differences in mEHI scores between the EMD and rhFGF-2 groups were statistically analyzed. Additionally, radiographic bone fill (RBF) was evaluated 6 months after surgery. RESULTS: The ICC of the mEHI was 0.575. The mEHI, redness score, and dehiscence scores were significantly higher in the rhFGF-2 group (n=33) than in the EMD group (n=46). Similar results were observed in the subgroup of patients aged 50 years or older, but not in those younger than 50 years. In the subgroup with non-contained bone defects, related results were noted, but not in the subgroup with contained bone defects. However, early wound healing did not correlate with RBF at 6 months after surgery. CONCLUSIONS: Within the limitations of this study, the findings suggest that early wound healing following the use of mPPT with rhFGF-2 is somewhat superior to that observed after mPPT with EMD. However, mEHI should be improved for use as a predictive tool for early wound healing and to reflect clinical outcomes after surgery.

Role of Macrophage Colony-Stimulating Factor for Staphylococcal Infection in the Oral Cavity.

OBJECTIVE: There are few valid indicators of oral infection owing to the complexity of pathogenic factors in oral diseases. Salivary markers are very useful for scrutinizing the symptoms of disease. To provide a reliable and useful predictive indicator of infection for opportunistic pathogens in individuals with compromised immune systems, such as those with periodontal diseases and Human Immunodeficiency Virus (HIV), this study examines opportunistic pathogens such as C. albicans and staphylococci and macrophage colony-stimulating factor (M-CSF) and CA125/MUC16 in saliva. The aim was to explore the correlations investigated among these factors. METHODS: Samples were divided into two groups (based on patient sex, the absence and presence of dentures in elderly, or HIV-positive patients and healthy subjects), and the correlation was analyzed in two groups of elderly patients with periodontal disease (64.5 ± 11.2 years old) and HIV-infected patients (41.9 ± 8.4 years old). Healthy subjects (33.8 ± 9.1 years old) were also analyzed as a control. Levels of C. albicans, staphylococci, and M-CSF, which is an immunological factor for the differentiation of macrophage, and CA125/MUC16, which provides a protective lubricating barrier against infection, were investigated. RESULTS: A significant and positive correlation between the levels of M-CSF and staphylococci was found in elderly individuals and HIV-positive patients treated with antiretroviral therapy. A significant and positive correlation between the levels of M-CSF and CD125/MUC16 was also found in both patients. These correlations were enhanced in both patients as compared with healthy subjects. CONCLUSION: Salivary M-CSF might be useful as a new indicator of opportunistic infection caused by staphylococci and a defense against infection in immunocompromised hosts.

Impact of COVID-19 spread on visit intervals and clinical parameters for patients with periodontitis in supportive periodontal therapy: a retrospective study.

PURPOSE: This study investigated the relationship between the number of days that hospital visits were postponed and changes in clinical parameters due to the spread of coronavirus disease 2019 (COVID-19), after the Japanese government declared a state of emergency in April 2020. METHODS: Regarding the status of postponement of appointments, we analyzed the patients who had visited the Nihon University Hospital at Matsudo for more than 1 year for supportive periodontal therapy (SPT) and classified them into low-, moderate- and high-risk subgroups according to the periodontal risk assessment (PRA). Clinical parameters for periodontal disease such as probing depth (PD), full-mouth bleeding score (FMBS), full-mouth plaque score, periodontal inflamed surface area (PISA), and periodontal epithelial surface area (PESA) were analyzed in 2 periods, from October 2019 to March 2020 and after April 2020. Correlation coefficients between days of deferral and the degree of changes in clinical parameters were calculated. RESULTS: The mean age of the 749 patients was 67.56±10.85 years, and 63.82% were female. Out of 749 patients, 33.24% deferred their SPT appointments after April 2020. The average total of postponement days was 109.49±88.84. The number of postponement days was positively correlated with changes in average PD (rs=0.474) and PESA (rs=0.443) in the high-risk subgroup of FMBS, and average PD (rs=0.293) and PESA (rs=0.253) in the high-risk subgroup of tooth number (TN). Patients belonging to the high-risk subgroups for both FMBS and TN had a positive correlation between postponement days and PISA (rs=0.56). CONCLUSIONS: The findings, the spread of COVID-19 appears to have extended the visit interval for some SPT patients. Moreover, longer visit intervals were correlated with the worsening of some clinical parameters for SPT patients with high PRA.

Changes in the components of salivary exosomes due to initial periodontal therapy.

PURPOSE: Exosomes are membrane vesicles that are present in body fluids and contain proteins, lipids, and microRNA (miRNA). Periodontal tissue examinations assess the degree of periodontal tissue destruction according to the probing depth (PD), clinical attachment loss (CAL), bleeding on probing, and X-ray examinations. However, the accurate evaluation of the prognosis of periodontitis is limited. In this study, we collected saliva from patients before and after initial periodontal therapy (IPT) and compared changes in the clinical parameters of periodontitis with changes in the components of salivary exosomes. METHODS: Saliva was collected from patients with stage III and IV periodontitis at the first visit and post-IPT. Exosomes were purified from the saliva, and total protein and RNA were extracted. Changes in expression levels of C6, CD81, TSG101, HSP70, and 6 kinds of miRNA were analyzed by western blots and real-time polymerase chain reaction. RESULTS: Patients with increased C6 expression after IPT had significantly higher levels of periodontal inflamed surface area (PISA), miR-142, and miR-144 before and after IPT than patients with decreased C6 expression after IPT. Patients with decreased and unchanged CD81 expression after IPT showed significantly higher PD, CAL, and PISA before IPT than after IPT. Patients with decreased and unchanged TSG101 expression after IPT had significantly higher PD before IPT than after IPT. Patients with increased HSP70 expression after IPT had significantly higher PD and PISA before and after IPT than patients with unchanged HSP70 after IPT. The expression levels of miR-142, miR-144, miR-200b, and miR-223 changed with changes in the levels of C6, CD81, TSG101, and HSP70 in the salivary exosomes of periodontitis patients before and after IPT. CONCLUSIONS: The expression levels of proteins and miRNAs in salivary exosomes significantly changed after IPT in periodontitis patients, suggesting that the components of exosomes could serve as biomarkers for periodontitis.

Utility of a haemoglobin test of gingival crevicular fluid: A multicentre, observational study.

OBJECTIVE: The purpose of this study was to verify the accuracy and utility of clinical parameters (plaque index, gingival crevicular fluid volume, probing depth, clinical attachment level, bleeding on probing and gingival index) and biochemical parameters (aspartate aminotransferase, protein and haemoglobin) in a longitudinal analysis during the supportive periodontal therapy period. SUBJECTS AND METHODS: A total of 279 test sites of 128 patients were investigated clinically and biochemically. After the first examination of clinical and biochemical parameters, periodontal support treatments were administered immediately and performed once every three months up to the second examination. RESULTS: All of the clinical and biochemical parameters were significantly lower at the second examination than at the first, except for the plaque index and bleeding on probing. Of these parameters, in particular, aspartate aminotransferase and haemoglobin in the gingival crevicular fluid were significantly reduced compared to those of the first examination in both the ≤4 and ≥5 mm probing depth groups, and they clearly suggested that periodontitis tended to recover. CONCLUSION: Adding the haemoglobin test to the bleeding on probing test strongly improves the accuracy of measurement of clinical parameters after periodontal treatment.

Identification of Nutritional Factors to Evaluate Periodontal Clinical Parameters in Patients with Systemic Diseases.

Nutritional factors reflect the periodontal parameters accompanying periodontal status. In this study, the associations between nutritional factors, blood biochemical items, and clinical parameters were examined in patients with systemic diseases. The study participants were 94 patients with heart disease, dyslipidemia, kidney disease, or diabetes mellitus. Weak negative correlation coefficients were found between nine clinical parameters and ten nutritional factors. Stage, grade, mean probing depth (PD), rate of PD 4−5 mm, rate of PD ≥ 6 mm, mean clinical attachment level (CAL), and the bleeding on probing (BOP) rate were weakly correlated with various nutritional factors. The clinical parameters with coefficients of determinations (R2) > 0.1 were grade, number of teeth, PD, rate of PD 4−5 mm, CAL, and BOP rate. PD was explained by yogurt and cabbage with statistically significant standardized partial regression coefficients (yogurt: −0.2143; cabbage and napa cabbage: −0.2724). The mean CAL was explained by pork, beef, mutton, and dark green vegetables with statistically significant standardized partial regression coefficients (−0.2237 for pork, beef, and mutton; −0.2667 for dark green vegetables). These results raise the possibility that the frequency of intake of various vegetables can be used to evaluate periodontal stabilization in patients with systemic diseases.

Association between Dietary Habit and Clinical Parameters in Patients with Chronic Periodontitis Undergoing Supportive Periodontal Therapy.

The recurrence risk evaluation has been emphasized in periodontal stabilization during supportive periodontal therapy (SPT). However, nutritional factors, e.g., dietary habits such as the frequency of eating vegetables, are rarely included in the evaluation. In this study, the effect of nutritional factors on clinical periodontal parameters was examined in a lifestyle-related investigation and a periodontal examination in patients with periodontitis undergoing SPT. A total of 106 patients were recruited. Tendencies toward a negative correlation were found between rate of a probing depth (PD) of 4-5 mm, rate of PD ≥ 6 mm, the bleeding on probing (BOP) rate, periodontal inflamed surface area (PISA), and various nutritional factors. The number of teeth was a clinical parameter with a significantly high R2 (≥0.10) influenced by environmental factors, whereas PD, PD of 4-5 mm, the BOP rate, and PISA were influenced by nutritional factors. These results suggested that environmental factors reflected clinical parameters showing long-term pathophysiology, such as the PD rate. Nutritional factors tended to affect the current inflammatory pathophysiology, such as the BOP rate, PISA, and PISA/periodontal epithelial surface area. Therefore, environmental and nutritional factors appear to be useful for evaluating the risk of periodontitis during SPT.

Study protocol for periodontal tissue regeneration with a mixture of autologous adipose-derived stem cells and platelet rich plasma: A multicenter, randomized, open-label clinical trial.

Introduction: Adipose-derived stem cells (ASCs) secrete various growth factors to promote wound healing and to regenerate various tissues, such as bone, cartilage, and fat tissue. Subcutaneous adipose tissue is a considerable cell source in clinical practice and can be collected relatively easily and safely under local anesthesia. Moreover, platelet-rich plasma (PRP), a plasma component containing many platelets purified by centrifuging the collected blood, also promotes wound healing. PRP can be easily gelled and is therefore attracting attention as a scaffolding material for transplanted cells. The usefulness of a mixture of ASCs and PRP for periodontal tissue regeneration has been in vitro demonstrated in our previous study. The aim of this study is to present the protocol of translation of tissue regeneration with ASCs and PRP into practical use, evaluating its efficacy. Methods: This study is a multicenter, randomized, open-label comparative clinical trial. Fifteen patients will be randomly assigned to the treatment with mixture of ASCs and PRP or enamel matrix derivate administration into periodontal tissue defects. Increase in height of new alveolar bone in the transplanted area will be evaluated. The evaluation will be performed using dental radiographs after 36 weeks of transplantation. Occurrence of adverse events will be evaluated as secondary outcome. Results: This clinical study was initiated after meeting the regulations to be complied with, including ethical review and regulatory notifications. Conclusions: If effective, this cell therapy using autologous mesenchymal stem cells can represent a useful medical technology for regeneration of periodontal defects.

Effect of Locally Delivered Minocycline on the Profile of Subgingival Bacterial Genera in Patients with Periodontitis: A Prospective Pilot Study.

This prospective pilot study aimed to evaluate the effect of minocycline-HCl ointment (MO), locally delivered as an adjunct to scaling and root planing (SRP), on subgingival microflora. A total of 59 periodontitis patients received SRP as an initial periodontal therapy. In the selected periodontal pockets with probing depths (PD) of 6−9 mm, the sites that exhibited a positive reaction following a bacterial test using an immunochromatographic device were subsequently treated with MO (SRP + MO group, n = 25). No additional treatment was performed at sites showing a negative reaction (SRP group, n = 34). In addition to subgingival plaque sampling, measurement of clinical parameters including PD, clinical attachment level (CAL), bleeding on probing (BOP), plaque index and gingival index (GI) were performed at baseline and 4 weeks after the initial periodontal therapy. The subgingival microflora were assessed by terminal restriction fragment-length polymorphism analysis. Relative to baseline values, the mean scores for PD-, CAL-, BOP-, and GI-sampled sites were significantly decreased post treatment in both groups (p < 0.01). The intra-comparisons showed a significant decrease in the counts of the genera Eubacterium, Parvimonas, Filifactor, Veillonella, Fusobacterium, Porphyromonas, Prevotella, and unknown species in the SRP + MO group (p < 0.05). Inter-comparisons indicated a significant decrease in the genera Veillonella in the SRP + MO group (p = 0.01). Combination therapy of SRP and local MO induced a change in the subgingival microbial community: particularly, the number of Veillonella spp. was markedly reduced.

Interleukin-1ß regulates odontogenic ameloblast-associated protein gene transcription in human gingival epithelial cells.

Junction epithelium (JE) is located apical to the bottom of the gingival sulcus and binds enamel to hemidesmosomes to protect the periodontal tissue from bacterial infection. Function of odontogenic ameloblast-associated protein (ODAM) is suggested by its expression sites (JE and maturation stage ameloblasts) to be involved in the adhesion between the JE and enamel, and odontogenesis. To analyze the changes in ODAM gene and protein expressions in inflamed gingiva, Ca9-22 gingival epithelial cells were stimulated with 1 ng/ml interleukin-1ß (IL-1ß) for 3-24 h, and ODAM mRNA and protein levels were analyzed by real-time PCR and Western blotting. Luciferase (LUC) constructs were made ligating various lengths of human ODAM gene promoters and performed LUC analyses in Ca9-22 cells. Gel shift and chromatin immunoprecipitation (ChIP) assays were performed. IL-1ß induced ODAM mRNA and protein levels at 6-24 h. IL-1ß increased LUC activities of the ODAM gene promoter constructs from - 85 to - 950. These activities were blocked by protein kinase A, tyrosine kinase, mitogen-activated protein (MAP) kinase kinase and phosphoinositide 3-kinase inhibitors. Gel shift and ChIP assays showed that IL-1ß induced CCAAT/enhancer-binding protein (C/EBP) ß and Yin Yang1 (YY1) binding to C/EBP1, 2, 3, and YY1 elements. These data indicate that IL-1ß stimulates ODAM gene transcription mediated through C/EBP1, C/EBP2, C/EBP3, and YY1 elements in the human ODAM gene promoter.

TNF-α regulates the composition of the basal lamina and cell-matrix adhesions in gingival epithelial cells.

Laminin 5, type 4 collagen, and α6ß4 integrin contribute to the formation of hemidesmosomes in the epithelia of periodontal tissues, which is critical for the development and maintenance of the dentogingival junction. As it is not known whether TNF-α alters the composition of the epithelial pericellular matrix, human gingival epithelial cells were cultured in the presence or absence of TNF-α. Treatment with TNF-α accelerated epithelial cell migration and closure of in vitro wounds. These data indicate unexpectedly, that TNF-α promotes the formation of the pericellular matrix around epithelial cells and enhances adhesion of epithelial cells to the underlying matrix, properties which are important for cell migration and the integrity of the dentogingival junction.

Epstein-Barr Virus Promotes the Production of Inflammatory Cytokines in Gingival Fibroblasts and RANKL-Induced Osteoclast Differentiation in RAW264.7 Cells.

Periodontitis is an inflammatory condition that causes the destruction of the supporting tissues of teeth and is a major public health problem affecting more than half of the adult population worldwide. Recently, members of the herpes virus family, such as the Epstein-Barr virus (EBV), have been suggested to be involved in the etiology of periodontitis because bacterial activity alone does not adequately explain the clinical characteristics of periodontitis. However, the role of EBV in the etiology of periodontitis is unknown. This study aimed to examine the effect of inactivated EBV on the expression of inflammatory cytokines in human gingival fibroblasts (HGFs) and the induction of osteoclast differentiation. We found that extremely high levels of interleukin (IL)-6 and IL-8 were induced by inactivated EBV in a copy-dependent manner in HGFs. The levels of IL-6 and IL-8 in HGFs were higher when the cells were treated with EBV than when treated with lipopolysaccharide and lipoteichoic acid. EBV induced IκBα degradation, NF-κB transcription, and RAW264.7 cell differentiation into osteoclast-like cells. These findings suggest that even without infecting the cells, EBV contributes to inflammatory cytokine production and osteoclast differentiation by contact with oral cells or macrophage lineage, resulting in periodontitis onset and progression.

Transcriptional regulation of human odontogenic ameloblast-associated protein gene by tumor necrosis factor-α.

OBJECTIVE: Odontogenic ameloblast-associated protein (ODAM) is produced by maturation stage ameloblasts and junctional epithelium (JE). The function of ODAM is thought to be involved in the attachment of teeth and JE. To elucidate transcriptional regulation of human ODAM gene in inflamed gingiva, we have analyzed the effects of TNF-α on the expression of ODAM gene in Ca9-22 and Sa3 gingival epithelial cells. MATERIALS AND METHODS: Total RNAs were extracted from Ca9-22 and Sa3 cells after stimulation by TNF-α (10 ng/ml). ODAM mRNA and protein levels were analyzed by qPCR and Western blotting. Luciferase (LUC) analyses were performed using LUC constructs inserted in various lengths of ODAM gene promoter. Gel shift and chromatin immunoprecipitation (ChIP) assays were carried out. RESULTS: TNF-α increased ODAM mRNA and protein levels at 3 to 24 h. TNF-α induced LUC activities of the ODAM gene promoter constructs, and the activities were inhibited by protein kinase A, tyrosine kinase, MEK1/2, PI3-kinase and NF-κB inhibitors. Gel shift and ChIP assays revealed that TNF-α increased CCAAT/enhancer-binding protein (C/EBP) ß and Yin Yang1 (YY1) binding to three kinds of C/EBPs and YY1 elements. CONCLUSION: These results demonstrate that TNF-α stimulates ODAM gene transcription via C/EBPs and YY1 elements in the human ODAM gene promoter.

Prospective Longitudinal Changes in the Periodontal Inflamed Surface Area Following Active Periodontal Treatment for Chronic Periodontitis.

Periodontal disease is a chronic inflammatory disease of the periodontal tissue. The periodontal inflamed surface area (PISA) is a proposed index for quantifying the inflammatory burden resulting from periodontitis lesions. This study aimed to investigate longitudinal changes in the periodontal status as evaluated by the PISA following the active periodontal treatment. To elucidate the prognostic factors of PISA, mixed-effect modeling was performed for clinical parameters, tooth-type, and levels of periodontal pathogens as independent variables. One-hundred-twenty-five patients with chronic periodontitis who completed the active periodontal treatment were followed-up for 24 months, with evaluations conducted at 6-month intervals. Five-times repeated measures of mean PISA values were 130+/-173, 161+/-276, 184+/-320, 175+/-417, and 209+/-469 mm2. Changes in clinical parameters and salivary and subgingival periodontal pathogens were analyzed by mixed-effect modeling. Plaque index, clinical attachment level, and salivary levels of Porphyromonas gingivalis were associated with changes in PISA at the patient- and tooth-level. Subgingival levels of P. gingivalis and Prevotella intermedia were associated with changes in PISA at the sample site. For most patients, changes in PISA were within 10% of baseline during the 24-month follow-up. However, an increase in the number of bleeding sites in a tooth with a deep periodontal pocket increased the PISA value exponentially.

Estimation of the Periodontal Inflamed Surface Area by Simple Oral Examination.

The periodontal inflamed surface area (PISA) is a useful index for clinical and epidemiological assessments, since it can represent the inflammation status of patients in one contentious variable. However, calculation of the PISA is difficult, requiring six point probing depth measurements with or without bleeding on probing on 28 teeth, followed by data input in a calculation program. More simple methods are essential for screening periodontal disease or in epidemiological studies. In this study, we tried to establish a convenient partial examination method to estimate PISA. Cross-sectional data of 254 subjects who completed active periodontal therapy were analyzed. Teeth that represent the PISA value were selected by an item response theory approach. The maxillary second molar, first premolar, and lateral incisor and the mandibular second molar and lateral incisor were selected. The sum of the PISAs of these teeth was significantly correlated with the patient's PISA (R2 = 0.938). More simply, the sum of the maximum values of probing pocket depth with bleeding for these teeth were also significantly correlated with the patient's PISA (R2 = 0.6457). The simple model presented in this study may be useful to estimate PISA.

MiR-200b suppresses TNF-α-induced AMTN production in human gingival epithelial cells.

Amelotin (AMTN) is an enamel protein that is localized in junctional epithelium (JE) of gingiva and suggested to be involved in the attachment between JE and tooth enamel. MicroRNA is a small non-coding RNA that regulates gene expression at post-transcriptional level by binding to the 3'-untranslated region (3'-UTR) of target mRNAs. In this study, we have analyzed the effects of miR-200b on the expression of AMTN in human gingival epithelial (Ca9-22) cells. Total RNAs and proteins were extracted from Ca9-22 cells transfected with miR-200b expression plasmid or miR-200b inhibitor and stimulated by TNF-α (10 ng/ml, 12 h). AMTN and inhibitor of kappa-B kinase beta (IKKß) mRNA and protein levels were measured by qPCR and Western blot. Human AMTN 3'-UTR that contains putative miR-200b target sites were cloned downstream of -353AMTN luciferase (LUC) plasmid. Ca9-22 cells were transfected with -353AMTN 3'-UTR LUC constructs and miR-200b expression plasmid, and LUC activities were measured with or without stimulation by TNF-α. TNF-α-induced AMTN mRNA levels were partially inhibited by miR-200b overexpression and enhanced by miR-200b inhibitor. TNF-α-induced IKKß mRNA and protein levels were almost completely inhibited by miR-200b. Transcriptional activities of -353AMTN 3'-UTR LUC constructs were induced by TNF-α and partially inhibited by miR-200b. IKKß inhibitor IMD0354 and NF-κB inhibitor triptolide decreased TNF-α-induced LUC activities. Furthermore, both inhibitors reduced AMTN mRNA levels in the presence or absence of TNF-α. These results suggest that miR-200b suppresses AMTN expression by targeting to AMTN and IKKß mRNAs in the human gingival epithelial cells.