Smoking and Drinking Adjusted Association between Head and Neck Cancers and Oral Health Status Related to Periodontitis: a Meta-Analysis.

BACKGROUND: Not so many reports about the association between head and neck cancer (HNC) and oral health status related to periodontitis (OHS-P) has been published in different countries with different methods. So, there is a need for an extensive meta-analysis with the total articles published until 2020. Hence, this study aimed to estimate the association between HNC and OHS-P through a meta-analysis. METHODS: Based on Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines, 22 studies were selected through PubMed and Cochrane Library databases. Meta-analysis using them was performed to evaluate the association. The risk of bias assessment using the Newcastle-Ottawa Scale (NOS) was applied to evaluate the quality of non-randomized studies. Publication bias was evaluated by funnel plot and Egger's regression test. RESULTS: Since heterogeneity was significant (I² = 88%, P < 0.001), we adopted the random effect model for 22 studies. Those with bad OHS-P, compared to those with good OHS-P, were more likely to have the risk of HNC by 2.4 times (odds ratio [OR], 2.42; 95% confidence interval [CI], 1.88-3.13) for random effect model. The association included publication bias (Egger's regression, P value < 0.001). The association among five studies (I² = 39%, P = 0.16) using alveolar bone loss (ABL) or clinical attachment level (CAL) for assessing periodontitis increased to OR of 3.85 (CI, 3.04-4.88) in the fixed effect model without publication bias (Egger's regression, P = 0.66). Moreover, the association was higher in 10 fair or good NOS studies (OR, 3.08) and in 7 Asian studies (OR, 2.68), which were from the fixed model without publication bias. CONCLUSION: Our meta-analysis showed that bad OHS-P was associated with the risk of HNC. The association was stronger in studies using ABL or CAL for assessing periodontitis.

Salivary S100 proteins screen periodontitis among Korean adults.

AIM: This study aims to evaluate the association of salivary S100A8 and A9 proteins with periodontitis and its screening ability for periodontitis cross-sectionally. MATERIAL AND METHODS: We selected 326 participants from the Yangpyeong Cohort: 218 participants with periodontitis and 108 participants without periodontitis. Stage II-IV periodontitis according to the modification of new international classification of periodontitis was considered as periodontitis. S100A8 and A9 were assayed using enzyme-linked immunosorbent assay kit. Age, sex, education, smoking, drinking, exercise, and metabolic syndrome were factored as confounders. Analyses of covariance and logistic regression analysis were applied to evaluate the association of S100A8 and A9 with periodontitis. Receiver operating characteristic curve was applied for screening ability. RESULTS: Those with periodontitis compared to those without periodontitis showed higher adjusted amount of S100A8 (3694 versus 6757 ng/ml, p < 0.001), but less adjusted amount of S100A9 (1341 versus 1030 ng/ml, p = 0.015). The screening ability of S100A8 and A9 on periodontitis was c-statistics of 0.69 (p < 0.001) for both S100A8 and A9, 0.67 for S100A8 and 0.63 (p < 0.001) for S100A9. CONCLUSIONS: Overall, salivary S100A8 and S100A9 could be practical markers for periodontitis. Its screening ability for periodontitis could be beneficial in clinics and at home.

Rehabilitation of lost teeth related to maintenance of cognitive function.

OBJECTIVE: As the era of aging comes, cognitive impairment (CI) is increasing. The impact of rehabilitation of lost tooth on CI remains unclear. This study aimed to investigate whether non-rehabilitated lost teeth (NRLT) is associated with CI among Korean elders. METHODS: A total of 280 elders comprising of 140 cases and 140 age-sex-matched controls were included in this cross-sectional study. CI was assessed using the Mini-Mental Status Examination (MMSE). NRLT was evaluated using panoramic radiograph and oral examination. NRLT was categorized into low (≤4) and high (≥5). Age, sex, education, drinking, smoking, exercise, obesity, hypertension, subclinical atherosclerosis, glucose, cholesterol, depression, and denture-wearing were considered as confounders. Conditional multivariate logistic regression analysis was applied to assess the adjusted association. RESULTS: NRLT was associated with increased CI after controlling for confounders (odds ratio [OR] = 1.06, 95% confidence interval [95% CFI]: 1.00-1.13). However, lost teeth were not associated with CI. Those with high NRLT (≥5) compared to those with low NRLT (≤4) was more likely to have CI by 2.7 times (OR = 2.74, 95% CFI = 1.28-5.86). CONCLUSION: Our data showed that NRLT was independently associated with CI. Hence, rehabilitation of the lost teeth could be important for the maintenance of cognitive function.

Deep sequencing salivary proteins for periodontitis using proteomics.

OBJECTIVES: Saliva is a bodily fluid transuded from gingival crevice fluid and blood and contains many proteins. Proteins in saliva have been studied as markers for periodontal diseases. Mass spectrometric analysis is applied to investigate biomarker proteins that are related to periodontitis. MATERIAL AND METHODS: Saliva samples were collected from 207 participants including 36 pairs matched for age, sex, and smoking who joined Yangpyeong health cohort. Periodontitis was defined by 2005 5th European guideline. Shotgun proteomics was applied to detect proteins from saliva samples. Principal component analysis and Ingenuity Pathway Analysis for canonical pathway and protein pathway were applied. Protein-protein interaction was also applied. Enzyme-linked immunosorbent assay (ELISA) was used to verify the candidate protein markers among another matched participants (n = 80). RESULTS: Shotgun proteomics indicated that salivary S100A8 and S100A9 were candidate biomarkers for periodontitis. ELISA confirmed that both salivary S100A8 and S100A9 were higher in those with periodontitis compared to those without periodontitis (paired-t test, p < 0.05). CONCLUSION: Our proteomics data showed that S100A8 and S100A9 in saliva could be candidate biomarkers for periodontitis. The rapid-test-kit using salivary S100A8 and S100A9 will be a practical tool for reducing the risk of periodontitis and promotion of periodontal health. CLINICAL RELEVANCE: A rapid-test-kit using salivary biomarkers, S100A8 and S100A9, could be utilized by clinicians and individuals for screening periodontitis, which might reduce the morbidity of periodontitis and promote periodontal health.

Association of toothbrushing and proximal cleaning with periodontal health among Korean adults: Results from Korea National Health and Nutrition Examination Survey in year 2010 and 2012.

AIM: Toothbrushing (TB), dental flossing (DF) and inter-dental brushing (IDB) are regarded as fundamental self-care methods for periodontal health. Few evidences on its effectiveness on periodontal health are available. Hence, this study aimed to evaluate the association of TB, DF, IDB and interaction effect with periodontal health. MATERIALS AND METHODS: The nationally representative 4,766 Korean adults aged 19 years and older were cross-sectionally surveyed in 2010 and 2012. Periodontal health was defined as Community Periodontal Index 1-2 for gingivitis and 3-4 for periodontitis. The information about variables was from interview and blood analyses. Multivariable logistic regression analyses and the interaction effect between TB and proximal cleaning (PC: DF and/or IDB) were applied. RESULTS: Toothbrushing thrice or more per day and DF were associated with a lower prevalence of periodontitis by both 44%, while the preventive fraction of DF on gingivitis was 30%. The preventive fraction of interaction effects between TB thrice or more and PC were 78% for periodontitis and 68% for gingivitis among 40-59 year age group. CONCLUSIONS: Toothbrushing and PC are independently associated with periodontal health. Hence, periodontists should recommend TB thrice or more per day and PC such as DF and IDB to promote periodontal health.

Diagnostic and prognostic ability of salivary MMP-9 for oral squamous cell carcinoma: A pre-/post-surgery case and matched control study.

Over 90% of oral cancers are oral squamous cell carcinoma (OSCC). Hitherto, early detection marker for OSCC has not been available. Hence, this study aimed to evaluate the diagnostic and prognostic ability of salivary matrix-metalloproteinase-9 (MMP-9) and 8-hydroxydeoxyguanosine (8-OHdG) for OSCC. Total of 318 participants with 106 cases and 212 controls were included: OSCC cases were from Seoul National University Dental Hospital and age, sex, and smoking matched controls were from Yangpyeong cohort. Unstimulated saliva was collected to determine MMP-9 and 8-OHdG using sensitive enzyme-linked immunosorbent assay. Multivariable linear regression and analysis of covariance (ANCOVA) were applied to evaluate the adjusted association of markers with OSCC. Wilcoxon sign rank sum test and Friedman test for median were applied to evaluate follow-up level of MMP-9 after surgery. Receiver operating characteristic curve was obtained for diagnostic ability. Salivary MMP-9 was associated with OSCC (ANCOVA and multivariable linear regression, p<0.05), while 8-OHdG was not. The diagnostic ability of MMP-9 was area under curve of 0.96 (100% specificity and 89.6% sensitivity, p<0.001). MMP-9 decreased dramatically after tumor surgery (p<0.05). Salivary MMP-9 could be a critical diagnostic and prognostic marker for OSCC.

Treponema denticola enolase contributes to the production of antibodies against ENO1 but not to the progression of periodontitis.

Autoantibodies against alpha-enolase (ENO1) are often detected in various infectious and autoimmune diseases. Anti-ENO1 antibody titers were reported to be associated with the severity of periodontitis in patients with rheumatoid arthritis. Because the enolase of the periodontal pathogen Treponema denticola (TdEno) has the highest homology with ENO1 among the enolases of human-associated bacteria, we hypothesized that anti-ENO1 autoantibodies produced during the immune response to TdEno may contribute to the progression of periodontitis and tested it in human and mouse systems. In human subjects with healthy periodontium or chronic periodontitis, a strong positive correlation between the levels of anti-TdEno and anti-ENO1 antibodies was observed. In addition, the purified anti-TdEno antibodies recognized ENO1 as well as TdEno in a dot blot, confirming the cross-reactivity between TdEno and ENO1. However, anti-ENO1 antibody titers were not associated with the severity of periodontitis. To further investigate the role of TdEno in the production of anti-ENO1 antibodies and the progression of periodontitis, mice received an oral gavage of P. gingivalis alone, subcutaneous immunization with TdEno alone, or both P. gingivalis oral gavage and TdEno immunization. Immunization with TdEno induced not only anti-TdEno but also anti-mouse Eno1 (mEno1) antibodies and increased the expression of TNFα in the gingival tissues. However, alveolar bone loss was not increased by TdEno immunization. In conclusion, autoreactive anti-ENO1/mEno1 antibodies that are produced as byproducts during the antibody response to TdEno play a minimal role in the progression of periodontitis in the absence of rheumatoid arthritis.

Hollow Abutment Screw Design for Easy Retrieval in Case of Screw Fracture in Dental Implant System.

The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA) and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA.

Marginal and internal fit of nano-composite CAD/CAM restorations.

OBJECTIVES: The purpose of this study was to compare the marginal and internal fit of nano-composite CAD-CAM restorations. MATERIALS AND METHODS: A full veneer crown and an mesio-occluso-distal (MOD) inlay cavity, which were prepared on extracted human molars, were used as templates of epoxy resin replicas. The prepared teeth were scanned and CAD-CAM restorations were milled using Lava Ultimate (LU) and experimental nano-composite CAD/CAM blocks (EB) under the same milling parameters. To assess the marginal and internal fit, the restorations were cemented to replicas and were embedded in an acrylic mold for sectioning at 0.5 mm intervals. The measured gap data were pooled according to the block types and measuring points for statistical analysis. RESULTS: Both the block type and measuring point significantly affected gap values, and their interaction was significant (p = 0.000). In crowns and inlays made from the two blocks, gap values were significantly larger in the occlusal area than in the axial area, while gap values in the marginal area were smallest (p < 0.001). Among the blocks, the restorations milled from EB had a significantly larger gap at all measuring points than those milled from LU (p = 0.000). CONCLUSIONS: The marginal and internal gaps of the two nano-composite CAD/CAM blocks differed according to the measuring points. Among the internal area of the two nano-composite CAD/CAM restorations, occlusal gap data were significantly larger than axial gap data. The EB crowns and inlays had significantly larger gaps than LU restorations.

Evaluation of the shear bond strength of resin cement to Y-TZP ceramic after different surface treatments.

The purpose of this study was to evaluate the effect of various surface treatments on the shear bond strength of Y-TZP (Yttria-Tetragonal Zirconia Polycrystal) ceramics with zirconia primer and two different resin cements both containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP). Zirconia blocks (LAVA, 3M ESPE, St. Paul, MN) were polished and assigned to five groups according to the surface treatment: (1) no further treatment (control); (2) airborne abrasion with Al2 O3 particles; (3) Z-PRIME Plus (Bisco, Schaumburg, IL) applied on polished zirconia; (4) Z-PRIME Plus applied on zirconia after airborne abrasion; and (5) tribochemical silica-coating performed with the CoJet system (3M ESPE) followed by application of ESPE®-Sil (3M ESPE). Each group was further divided into one of two resin cements: Panavia F2.0 (Kuraray, Kurashiki, Okayama, Japan) and Clearfil SA Luting (Kuraray). Resin cement placed inside a gel-cap was polymerized on the zirconia surface. Shear bond strength was tested with a universal testing machine at 0.5 mm/min. One-way analysis of variance and paired t-test were done. (p < 0.05), and scanning electron microscope (SEM) images were taken. Zirconia primer applied after airborne abrasion significantly increased the shear bond strength resulting in the highest value for both resin cements. Control groups for both cements showed the weakest value for shear bond strength. No significant differences were found between the shear bond strengths of the individual resin cements applied to zirconia surfaces treated the same way. In conclusion, the combined surface treatment of airborne abrasion followed by a zirconia primer is recommended for zirconia bonding with Panavia F2.0 and Clearfil SA Luting cements.