Consequences of Tooth Loss on Oral Function and need for Replacement of Missing Teeth Among Patients Attending Muhimbili Dental Clinic

Tanzanian oral health services constitute mainly of tooth extractions. Consequently, individuals susceptible to dental caries and periodontal diseases will have a substantial number of missing teeth, which can affect oral function. The main objective of this study was to determine the consequences of tooth loss on the oral function and need for replacement of lost teeth among patients seeking treatment at the School of Dentistry MUHAS. During a period of three months, patients seeking dental treatment at the School of Dentistry were recruited for the study. Criteria included age of 20 years and above with one or more missing teeth except for third molars. Participants were interviewed for demographic information, chewing ability, symptoms of temporomandibular disorder and perceived need for replacement of missing teeth. Afterwards the subjects were examined to asses: caries status, tooth mobility, occlusal tooth wear, over eruption of unopposed teeth, and signs of temporomandibular disorders. Data was analyzed using Statistical Package for Social Sciences SPSS 16. For comparison of proportions, chi-square analysis and t test were used. A linear regression analysis was performed, with the chewing ability score as the dependent variable and number of POP as the independent variable A total of 361 subjects with mean age of 40.2 years (s.d. = 14.2, range = 20-93 years) were recruited into the study. About half 175 (48.5%) of the subjects reported some difficulty with chewing. Generally the fewer the occluding pairs present the greater the difficulty in chewing observed. Subjects with more than 6 posterior occlusal pairs appeared to have little problem in chewing across the whole range of foods. The frequency of signs and symptoms of TMD and excessive tooth wear increased with decreasing number of posterior occluding pairs, being more evident in subjects with less than 3 posterior occlusal pairs remaining. Over a third of the participants had one or more teeth with severe overeruption but none reported impairment of oral function. More than half of the subjects needed replacement for missing teeth. From this study, it is concluded that tooth loss leading to a dentition of 5 to 6 occlusal pairs impairs chewing of hard foods but not soft foods. Extensive loss of teeth leading to less than 3 POP is associated with increased symptoms of TMD and excessive vii tooth wear of occluding teeth. Need for replacement of missing teeth is high for both anterior and posterior regions with the cost of dentures being the main barrier to replacement of missing teeth. Dental personnel should make an effort to identify individuals with risk of tooth loss in order to retain at least 6 well-distributed posterior occlusal pairs. Dental laboratory services need improvement in order to be able to provide quality replacement of missing teeth at affordable costs. Further long-term multicenter studies to evaluate the consequence of tooth loss and assist in giving a more accurate projection needs for dentures nationwide are required

The Randomized Shortened Dental Arch Study: Tooth Loss

The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant

Risk of Tooth Loss After Cigarette Smoking Cessation

INTRODUCTION. Little is known about the effect of cigarette smoking cessation on risk of tooth loss. We examined how risk of tooth loss changed with longer periods of smoking abstinence in a prospective study of oral health in men. METHODS. Research subjects were 789 men who participated in the Veterans Administration Dental Longitudinal Study from 1968 to 2004. Tooth status and smoking status were determined at examinations performed every 3 years, for a maximum follow-up time of 35 years. Risk of tooth loss subsequent to smoking cessation was assessed sequentially at 1-year intervals with multivariate proportional hazards regression models. Men who never smoked cigarettes, cigars, or pipes formed the reference group. Hazard ratios were adjusted for age, education, total pack-years of cigarette exposure, frequency of brushing, and use of floss. RESULTS. The hazard ratio for tooth loss was 2.1 (95% confidence interval [CI], 1.5-3.1) among men who smoked cigarettes during all or part of follow-up. Risk of tooth loss among men who quit smoking declined as time after smoking cessation increased, from 2.0 (95% CI, 1.4-2.9) after 1 year of abstinence to 1.0 (95% CI, 0.5-2.2) after 15 years of abstinence. The risk remained significantly elevated for the first 9 years of abstinence but eventually dropped to the level of men who never smoked after 13 or more years. CONCLUSION. These results indicate that smoking cessation is beneficial for tooth retention, but long-term abstinence is required to reduce the risk to the level of people who have never smoked.U.S. Department of Veterans Affairs Epidemiology (Merit Review grant); Massachusetts Veterans Epidemiology Research and Information Center; National Institutes of Health (R01 DA10073, R03 DE016357, R15 DE12644, K24 DE00419

Effectiveness of supportive periodontal therapy on tooth survival among patients with chronic periodontitis

INTRODUCTION: Prevention of tooth loss and maintaining favorable periodontal status are the ultimate goals of periodontal therapy. The aim of this study was to evaluate the effectiveness of non-surgical periodontal therapy and supportive periodontal care in arresting the progression of chronic periodontitis and in preventing tooth loss. MATERIALS AND METHODS: Periodontal charts, self-reported medical history, and interleukin-1 (IL-1) polymorphism genotypes of 100 patients were obtained from the University of Pittsburgh School of Dental Medicine Dental Registry and DNA Repository (DRDR) after screening of 4,825 subjects. In our study we have included third molars, teeth lost during active periodontal treatment (APT), and those lost during supportive periodontal care (SPC). We used tooth loss (TL) and clinical attachment loss (CAL) as outcomes of disease affection in our analysis. Fisher’s exact test was used to investigate the association between tooth loss and different risk factors. Paired t-test was conducted to detect the difference in means of CAL between baseline and final periodontal assessments. RESULTS: There were 59 patients (36 males and 23 females with an average age of 52 years) that lost at least one tooth. Tooth mortality rate declined in patients who attended supportive periodontal program for six years compared to those who received supportive periodontal therapy for one year only (0.52 and 3.4 teeth/patient/year, respectively). Increased risk of tooth loss was found to be associated with diabetes (P=0.01), as well as high blood pressure (P<0.0001). We did not find an association between tooth loss and polymorphisms in interleukin IL-1α/IL-1β (rs1800587, P=0.36 and rs1143634, P=0.51, respectively). During the first year of supportive periodontal treatment, the clinical attachment loss showed a significant reduction (CAL gain of 0.36 mm, P=0.0697). Moreover, a significant increase in CAL was noted in the group of patients who attended regular periodontal maintenance for six years (CAL progression of 0.38mm, P=0.037). CONCLUSION: Our findings suggested that supportive periodontal therapy is effective for the long-term stability of periodontal disease in high-risk patients in our sample

Effect of Pulp Protection Technique on the Clinical Performance of Amalgam Restorations: Three-Year Results

This study evaluated the influence of the pulp protection technique on clinical performance of amalgam restorations after three years, with particular reference to post-operative sensitivity and secondary caries. One hundred and twenty (120) Class II amalgam restorations (68 premolars, 52 molars; 78 MOD, 42 OD/MO) were placed in 30 participants (four restorations per participant).The restorations were divided into four groups according to the pulp protection technique used: copal varnish; 2% neutral sodium fluoride; adhesive resin and no pulp protection. The parameters evaluated were post-operative sensitivity, staining of the dental structure, tooth vitality, partial or total loss of the restoration and secondary caries. One hundred and eight (108)restorations were available for evaluation after three years. No partial or total loss of restorations had occurred; all teeth were vital, no tooth structure staining or secondary caries was detected in any of the restored teeth. Post-operative sensitivity was observed only in two restorations at baseline and at seven-days. The three year clinical performance of teeth restored with a high copper dispersed phase amalgam was not affected by the choice of pulp protection technique

Wear of human teeth: a tribological perspective

The four main types of wear in teeth are attrition (enamel-on-enamel contact), abrasion (wear due to abrasive particles in food or toothpaste), abfraction (cracking in enamel and subsequent material loss), and erosion (chemical decomposition of the tooth). They occur as a result of a number of mechanisms including thegosis (sliding of teeth into their lateral position), bruxism (tooth grinding), mastication (chewing), toothbrushing, tooth flexure, and chemical effects. In this paper the current understanding of wear of enamel and dentine in teeth is reviewed in terms of these mechanisms and the major influencing factors are examined. In vitro tooth wear simulation and in vivo wear measurement and ranking are also discussed

Oral Inflammation, Tooth Loss, Risk Factors, and Association with Progression of Alzheimer’s Disease

Periodontitis is a polymicrobial chronic inflammatory disease of tooth-supporting tissues with bacterial etiology affecting all age groups, becoming chronic in a subgroup of older individuals. Periodontal pathogens Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola are implicated in the development of a number of inflammatory pathologies at remote organ sites, including Alzheimer’s disease (AD). The initial inflammatory hypothesis proposed that AD hallmark proteins were the main contributors of central nervous system (CNS) inflammation. This hypothesis is expanding to include the role of infections, lifestyle, and genetic and environmental factors in the pathogenesis of AD. Periodontal disease (PD) typifies a condition that encompasses all of the above factors including pathogenic bacteria. These bacteria not only are the source of low-grade, chronic infection and inflammation that follow daily episodes of bacteremia arising from everyday tasks such as brushing, flossing teeth, chewing food, and during dental procedures, but they also disseminate into the brain from closely related anatomical pathways. The long-term effect of inflammatory mediators, pathogens, and/or their virulence factors, reaching the brain systemically or otherwise would, over time, prime the brain’s own microglia in individuals who have inherent susceptibility traits. Such susceptibilities contribute to inadequate neutralization of invading agents, upon reaching the brain. This has the capacity to create a vicious cycle of sustained local inflammatory milieu resulting in the loss of cytoarchitectural integrity and vital neurons with subsequent loss of function (deterioration in memory). The possible pathways between PD and AD development are considered here, as well as environmental factors that may modulate/exacerbate AD symptoms

Stator iron loss of tubular permanent-magnet machines

While methods of determining the iron loss in rotating permanent-magnet (PM) machines have been investigated extensively, the study of iron loss in linear machines is relatively poorly documented. This paper describes a simple analytical method to predict flux density waveforms in discrete regions of the laminated stator of a tubular PM machine, and employs an established iron loss model to determine the iron loss components, on both no load and on load. Analytical predictions are compared with the iron loss deduced from finite-element analyses for two tubular PM machine designs, and it is shown that if a machine has a relatively high electrical loading, the on-load iron loss can be significantly higher than the no-load value

Associations between tooth loss and prognostic biomarkers and the risk for cardiovascular events in patients with stable coronary heart disease

Background: Underlying mechanisms behind the hypothesized relationship between periodontal disease (PD) and coronary heart disease (CHD) have been insufficiently explored. We evaluated associations between self-reported tooth loss- a marker of PD- and prognostic biomarkers in 15,456 (97%) patients with stable CHD in the global STABILITY trial. Methods and results: Baseline blood samples were obtained and patients reported their number of teeth according to the following tooth loss levels: “26–32 (All)” [lowest level], “20–25”, “15–19”, “1–14”, and “No Teeth” [highest level]. Linear and Cox regression models assessed associations between tooth loss levels and biomarker levels, and the relationship between tooth loss levels and outcomes, respectively. After multivariable adjustment, the relative biomarker increase between the highest and the lowest tooth loss level was: high-sensitivity C-reactive protein 1.21 (95% confidence interval, 1.14–1.29), interleukin 6 1.14 (1.10–1.18), lipoprotein-associated phospholipase A2 activity 1.05 (1.03–1.06), growth differentiation factor 15 1.11 (1.08–1.14), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) 1.18 (1.11–1.25). No association was detected for high-sensitivity troponin T 1.02 (0.98–1.05). Some attenuation of the relationship between tooth loss and outcomes resulted from the addition of biomarkers to the multivariable analysis, of which NT-proBNP had the biggest impact. Conclusions: A graded and independent association between tooth loss and several prognostic biomarkers was observed, suggesting that tooth loss and its underlying mechanisms may be involved in multiple pathophysiological pathways also implicated in the development and prognosis of CHD. The association between tooth loss and cardiovascular death and stroke persisted despite comprehensive adjustment including prognostic biomarkers