Biological Effects of "Inflammageing" on Human Oral Cells: Insights into a Potential Confounder of Age-Related Diseases

OBJECTIVES

The term "inflammageing" describes the process of inflammation-induced aging that leads living cells to a state of permanent cell cycle arrest due to chronic antigenic irritation. This in vitro study aimed to shed light on the mechanisms of "inflammageing" on human oral cells.

METHODS

Primary cultures of human gingival fibroblasts (hGFs) were exposed to variable pro-inflammatory stimuli, including lipopolysaccharide (LPS), Tumor Necrosis Factor-alpha (TNFa), and gingival crevicular fluid (GCF) collected from active periodontal pockets of systemically healthy patients. Inflammageing was studied through two experimental models, employing either late-passage ("aged") cells (p. 10) that were exposed to the pro-inflammatory stimuli or early-passage ("young") cells (p. 1) continuously exposed during a period of several passages (up to p. 10) to the above-mentioned stimuli. Cells were evaluated for the expression of beta-galactosidase activity (histochemical staining), senescence-associated genes (qPCR analysis), and biomarkers related to a Senescence-Associated Secretory Phenotype (SASP), through proteome profile analysis and bioinformatics.

RESULTS

A significant increase (p < 0.05) in beta-galactosidase-positive cells was observed after exposure to each pro-inflammatory stimulus. The senescence-associated gene expression included upregulation for CCND1 and downregulation for SUSD6, and STAG1, a profile typical for cellular senescence. Overall, pro-inflammatory priming of late-passage cells caused more pronounced effects in terms of senescence than long-term exposure of early-passage cells to these stimuli. Proteomic analysis showed induction of SASP, evidenced by upregulation of several pro-inflammatory proteins (IL-6, IL-10, IL-16, IP-10, MCP-1, MCP-2, M-CSF, MIP-1a, MIP-1b, TNFb, sTNF-RI, sTNF-RII, TIMP-2) implicated in cellular aging and immune responses. The least potent impact on the induction of SASP was provoked by LPS and the most pronounced by GCF.

CONCLUSION

This study demonstrates that long-term exposure of hGFs to various pro-inflammatory signals induced or accelerated cellular senescence with the most pronounced impact noted for the late-passage cells. The outcome of these analyses provides insights into oral chronic inflammation as a potential confounder of age-related diseases.

The Effect of Denture Adhesives on Denture Quality and Occlusal Force

INTRODUCTION

Complete dentures (CDs) have been associated with substantial problems regarding edentulous patient's function. Denture adhesives seem to be useful adjuncts to improving retention and stability.

METHODS

A clinical study was undertaken to investigate the effect of a denture adhesive (DA) on function in complete denture wearers along with the quality of their CDs. Thirty complete denture wearers participated in the study. The first phase of the experimental procedure comprised 3 groups of measurements performed at 3 distinct time points: the initial measurement (T1), a 2nd measurement after 15 days of DA daily application (T2), and a 3rd measurement following a 15-day washout period (T3). The second phase consisted of the follow-up measurements. The measurements included: recording of relative occlusal force (ROF), distribution of occlusal contacts (DOC) and center of force (COF) using the T-Scan 9.1 device and functional assessment of dentures using the FAD index.

RESULTS

The DA use induced a statistically significant increase in ROF (p-value=0.003) and decrease in COF (p-value⟨0.001) and DOC (p-value=0.001). The overall FAD score significantly improved (p-value⟨0.001).

CONCLUSIONS

The use of the DA improved the occlusal force, the distribution of occlusal contacts as well as the qualitative characteristics of CDs.

Exploring Adaptation and Satisfaction in Copied Complete Dentures Regarding Two Different Occlusal Schemes

PURPOSE

To compare patient adaptation to and satisfaction with new complete dentures fabricated with a duplication construction protocol (DCP) using two different occlusal schemes, bilateral balanced (BBO) and lingualized (LO).

MATERIALS AND METHODS

Twenty complete denture wearers who received replacement DCP dentures participated in this study. Ten participants received complete dentures with a BBO scheme, and the other 10 received DCP dentures with an LO scheme. All of them evaluated their prostheses subjectively through the Oral Health Impact Profile-20 (OHIP-20) and the Complete Denture Satisfaction (CDS) questionnaires before treatment and at 3- and 6-month posttreatment intervals. The new prostheses were also normatively evaluated by recording the location and number of sore spots present at the scheduled early adjustment visits. Data were analyzed with nonparametric tests to identify differences in patient responses between groups and within each group at each evaluation interval point (α = .05).

RESULTS

The within-group comparisons revealed statistically significant improvement for both denture groups (P < .05), while the between-group comparisons did not record statistically significant differences at the overall evaluation period (P > .05). Significant within-group differences were recorded in the pain, functional limitation, and psychologic disability domains of the OHIP-20 questionnaire and the comfort, esthetics, and stability domains of the CDS questionnaire.

CONCLUSION

The patients' adaptation to and satisfaction with newly constructed DCP dentures improved significantly for both BBO and LO denture groups throughout the evaluation period. The mean number of early adjustment visits was equal for both the BBO and LO denture groups.

HBV viremia in newborns of HBsAg(+) predominantly Caucasian HBeAg(-) mothers

BACKGROUND

Hepatitis B virus infection is an important public health problem worldwide and eliminating mother-to-infant transmission is important to decrease the prevalence of chronic HBV-infection. Although, immunoprophylaxis given at birth largely prevents mother-to-infant transmission, perinatal HBV viremia has been reported in HBsAg(-) newborns born mainly to HBeAg(+) women in endemic areas.

OBJECTIVES

To examine the incidence of perinatal HBV viremia in newborns of HBsAg(+) predominantly HBeAg(-) mothers.

STUDY DESIGN

Peripheral blood was obtained at birth from 109 HBsAg(+) mothers and their newborns before the administration of active-passive immunoprophylaxis. Infants were prospectively followed and appropriately vaccinated.

RESULTS

Although most (92.7%) of the HBsAg(+) mothers were HBeAg(-), 73.4% had detectable HBV viremia. Neonatal viremia was detected in 3/8 (37.5%) and 24/101 (23.8%) newborns of HBeAg(+) and HBeAg(-) mothers, respectively (p=0.386). However, HBV-DNA levels were significantly higher in newborns of HBeAg(+) mothers (p=0.025). No child developed chronic HBV infection, but one child had evidence of subclinical hepatitis.

CONCLUSIONS

Although the clinical significance of low viremia levels in almost one in four newborns of HBsAg(+) mothers in a low endemicity area is unclear, it may enhance our understanding of HBV mother-to-infant transmission.

The effect of denture quality attributes on satisfaction and eating difficulties

OBJECTIVES

The development of a measure, with complimentary normative and perceived needs, for the investigation of functional impairment of individual patients and the investigation of the physical causative bases of impairment.

SUBJECTS

A consecutive sample of 119 complete denture (CD) wearers attending a Greek department of prosthetic dentistry took part in the study. All subjects presented with some complaint(s) of their dentures.

METHOD

Functional assessment of dentures (FAD) criteria and structured questionnaires were used covering denture satisfaction (DS) and food difficulties with CDs. The questions used a five-point Likert scale.

RESULTS

The results showed that there were statistically significant associations between satisfaction from dentures and eating specified foods. Statistically significant associations were also found between denture qualities and movement of upper dentures and difficulty eating specified foods, but not with an open question on the difficulty of eating unspecified foods.

CONCLUSIONS

This study successfully validated a suitable model for the combined evaluation of denture quality with clear diagnostic criteria and closed questions on DS and perceived difficulties when eating specified foods. This could predict the need for treatment, monitor the impact of care and provide a feasible measure to meet the need of everyday clinical situations.

Validation of communication between elderly denture wearers and dentists: a questionnaire on satisfaction with complete dentures using semi-structured interviews

OBJECTIVES

To validate a semi-structured interview (SSI) for communication between complete denture wearers and dentists.

DESIGN

A SSI using a questionnaire with eight questions on satisfaction with complete dentures (CD): covering function, aesthetics and comfort. The first seven questions used a five-point Likert scale and the last was dichotomous. Two dentists, carefully trained in the use of the structured questionnaire, administered the SSI.

SETTING

A Greek Department of Prosthetic Dentistry.

SUBJECTS

A consecutive sample of 78 CD wearers took part in the study. All subjects presented with complaints from their dentures.

INTERVENTION

All participants and their dentures underwent clinical examination.

RESULTS

The method showed good reliability, verified by the Cronbach alpha (0.86). Both dentists used the questionnaire produced very similar results. (Wilcoxon test 61-99%). Further, the association of the answers with respect to the five-point Likert scale was very high; all gamma coefficients were statistically significant except for pain and discomfort from the upper CD (CDU).

CONCLUSIONS

This method of communication between patients and dentists is reliable and can be used to give good repeatability for qualitatively assessing satisfaction with CD. It can be valuable for clinical use and for extending the study of denture quality to establish outcome measures based on the subjective criteria of satisfaction.

Food choices and eating difficulty among elderly edentate patients in Greece

AIMS

To evaluate food choice and eating difficulty experienced by older Greek edentate patients.

SUBJECTS

Three samples of patients seeking provision of replacement dentures were studied. A primary study of urban mainland U1 (n=54) and island rural R1 samples (n=84) was followed by a mainland urban U2 sample (n= 19) in the Secondary study.

SETTING

Greek dental clinics.

INTERVENTION

Semi-structured interviews (SSI) were employed, using both open and closed questions.

DESIGN

The primary study used SSI to identify eating difficulty experienced by two culturally different Greek groups. The secondary study established patterns of difficulty for comparisons between an urban Greek population and northern European urban studies.

MAIN OUTCOME MEASURES

The prevalence of eating difficulty, the degree of difficulty eating specified foods and the exclusion of foods because difficult.

RESULTS

Most patients expressed difficulty eating at least one type of food, a high percentage of these patients were willing to eat foods found difficult, while others use particular methods of food preparation that make food easier to eat. Chicken illustrated the importance of specifying the method of cooking when questioning eating difficulties. Roast meats provided insight into the more difficult end of the food range. Raw vegetables were rated difficult. Apples and oranges were also food of particular interest.

CONCLUSIONS

The semi-structured interview method provides a successful method to identify eating difficulty and food choices by older Greek complete denture wearers. Differences, probably largely cultural, were identified between Greek island rural and mainland urban communities. Greek food choices differed favourably from an English sample, strikingly in that Greek patients report continuing to eat difficult foods despite difficulty eating them. This may be relevant to health data on Greek populations that show better mortality statistics despite adverse factors such as high prevalence of smoking.

Validation of indices for functional assessment of dentures

AIMS

To validate an assessment of qualities of complete dentures that may relate to functional success.

SUBJECTS

A consecutive sample of 131 complete denture wearers took part in the study.

SETTING

a Greek department of prosthetic dentistry.

INTERVENTION

All participants and their dentures underwent clinical examination.

DESIGN

The Functional Assessment of Dentures (FAD) 10-item criteria' describing clinical factors of denture quality was used. The rationale for selecting these particular criteria was to include a range of clinical factors to produce an overall assessment of complete dentures. The 10-item scale was examined for Internal Consistency and Construct Validity providing a summated rating scale whose total score could be used as an index for the quality of dentures.

RESULTS

Both intra- and inter-examiner agreement for all 10 dichotomous scale criteria were all good or very good; the intra-examiner Kappa values were 0.72 to 0.91 and the inter- examiner values were 0.72 to 0.99. Statistical analysis revealed that a 7-item summated rating scale could be constructed which has marginally better internal consistency (reliability) and Construct Validity with fewer questions.

CONCLUSIONS

The FAD criteria' can be used to give good repeatability. The adjustments made to the original summation scale, if confirmed by new studies, would further increase the practical utility of a FAD index for general dentists. In due course with data from future studies, discrimination on weighting of items will be appropriate to relate the impact of denture quality on quality of life.

Evaluating dental status and prosthetic need in relation to medical findings in Greek patients suffering from idiopathic Parkinson's disease

Parkinson's disease is one of the common neurological conditions which predominantly affects the elderly but increasingly also younger people. Sufferers present persistent problems with oral health aggravated by extensive tooth loss leading to an impaired dentition. Greece and other countries experiencing the same demographic trends, face growing numbers of sufferers. This study surveyed the dental status and the need for dental treatment of a sample of Greek patients with Parkinson's disease. A structured questionnaire was used. 30% of the participants were younger sufferers. 80% of the elderly group were young elderly. 98% of the participants were denture wearers. Extensive oral problems were recorded in all participants.

The development of a simple objective test of mastication suitable for older people, using chewing gums

AIMS

To develop and assess a simple test for evaluating the mastication of visco-elastic foods and prosthodontic success subsequent to treatment of older people.

METHOD

The weight lost from chewing gum during mastication tests and the saliva secreted is weighed. The percentage of the original gum weight that is chewed out in a defined number of strokes is termed the Masticatory Effectiveness (ME) MATERIAL: Five edentate and three dentate volunteers were selected to provide a range of dental states and age. Four commercially available chewing gums of different origins and perceived hardness were tested, one without sweetener acted as a control for salivary stimulation.

INTERVENTION

Pre-weighed samples of each gum were chewed, each for defined numbers of strokes. The saliva secreted was collected and weighed. The chewed gum was desiccated and the total weight loss of sweeteners chewed out provided an objective measure of chewing performance.

RESULTS

Weight loss showed large differences between gums, between subjects and the number of strokes. ME was significantly correlated with salivary secretion rates for two subjects. The interaction between subject and gum was statistically significant, established by an ANOVA model, the value of which is shown for multivariate studies. Differential success between gums of different thickness may provide evaluation of denture stability.

CONCLUSIONS

Measuring the weight lost from gums during chewing provides a simple test of masticatory effectiveness of visco-elastic foods. This has particular value both in functional assessment of older people and in physiological research.

X-ray diffraction study of crystalline phases of calcium sulphate in alginate impression materials

In the present study the crystalline phases of calcium sulphate present in various commercially available alginate impression materials were identified by means of x-ray diffraction. The diffractograms obtained indicated that the predominant crystalline phase in most materials was calcium sulphate dihydrate and confirmed the presence of calcium sulphate hemihydrate in some products.

Relationship between pH changes and dimensional stability in irreversible hydrocolloid impression material during setting

This study investigated the relationship between pH changes and dimensional stability during setting of irreversible hydrocolloid impression materials. Twelve specimens of seven irreversible hydrocolloid materials were used; pH readings for 20 minutes and dimensional (mass and linear) measurements for a 24-hour period were taken after mixing. The study of the curves and the comparison between them in range and in variance, together with the application of the t test, showed that pH changes were strongly related to the linear and mass changes derived from the variety and the chemistry of the included components and their amounts.

The effect of pH changes at the impression-stone cast interface during setting

It is of great clinical significance to obtain a cast that reflects the optimal reproducibility of the irreversible hydrocolloid materials. This study investigated whether pH changes that occur during setting (as a single sequence of the chemical reactions that lead to gelation and the formation of the impression) are related to the reproducibility of irreversible hydrocolloids. The results indicated that as the pH range was increased for materials with alkaline pH values, the reproducibility improved. The opposite effect was noticed in materials with acidic pH values. It was also demonstrated that when the pH curve was in the acidic range, it was closer to the neutral pH values, and the reproducibility of the irreversible hydrocolloid was better.

The relation between thermal and pH changes in alginate impression materials

OBJECTIVES

The purpose of this study was to determine if pH changes are related to thermal changes during setting in alginate impression materials, and to investigate the possibility of establishing a mathematical model between thermal and pH changes.

METHODS

Thermal and pH changes were recorded during the 20 min gelation period following the mixing of five commercial alginate materials. The data obtained were plotted and statistically analyzed using a student's T-test, multiplicative, linear and reciprocal analyses at a significance level of p<0.05. These analyses were used to determine the differences between various materials and to establish regression models between thermal and pH changes for each of the materials tested.

RESULTS

For all samples, the pH values fell within the first minutes from the alkaline range into the neutral and even into the acidic range, while the initial sharp fall in temperature was followed by a subsequent gradual increase. Differences in the final gel structures of the alginate materials were shown to be related to the differences in thermal and pH changes during setting. This could be expected from their various chemical compositions such as the variety of components, the chemical forms of principal components and the proportion of each component.

SIGNIFICANCE

This work contributes to the development of a mathematical model relating pH changes and thermal changes to form a basis for the correlation between chemical properties and characteristics in practical use.