Vasoactive intestinal polypeptide (VIP) and VPAC1 receptor in adult human dental pulp in relation to caries

Objective: To quantitatively measure VIP levels and to qualitatively study the distribution of VIP fibres and demonstrate the presence of the VPAC1 receptor in human dental pulp from carious and non-carious adult human teeth. Design: Dental pulp samples were collected from non-carious, moderately carious and grossly carious adult human teeth. VIP levels were determined using radioimmunoassay. The distribution of VIP fibres was studied using immunohistochemistry. The VPAC1 receptor protein expression was determined by Western blotting. Results: VIP levels were found to be significantly elevated in the dental pulp of moderately carious compared with non-carious (p = 0.0032) or grossly carious teeth (p = 0.0029). The distribution of VIP fibres was similar in non-carious and carious teeth, except that nerve bundles appeared thicker in the pulp samples from carious compared with non-carious teeth. Western blotting indicated that the VPAC1 receptor proteins were detected in similar levels in pooled dental pulp samples from both carious and non-carious teeth. Conclusion: It is concluded that quantitative changes in the levels of VIP in human dental pulp during the caries process and the expression of VPAC1 receptor proteins in membrane extracts from carious and non-carious teeth suggests a role for VIP in modulating pulpal health and disease. © 2006 Elsevier Ltd. All rights reserved.

Caries-induced changes in the expression of pulpal neuropeptide Y

Recent evidence suggests that the sympathetic nervous system may have a role in modulating neurogenic inflammation and bone remodelling. Neuropeptide Y (NPY) is a well-characterized neuropeptide transmitter in the peripheral sympathetic nervous system. NPY is known to be present in human dental pulp; however, quantitative data on NPY levels in pulpal health and disease in an adult population remain to be determined. The aims of the current study were to assess, quantitatively, NPY levels by radioimmunoassay and confirm the distribution of NPY fibres by immunocytochemistry in carious and non-carious adult human pulp tissue. Our results suggest changes in the levels and distribution of NPY in human dental pulp during the caries process, with significantly higher levels of NPY in carious compared with non-carious adult human teeth. Within the carious samples studied, our finding, that NPY levels were significantly elevated in mild/moderate caries, concurs with the hypothesis that NPY could have a modulatory role in pulpal inflammation and in reparative dentine formation. © 2006 Eur J Oral Sci.

PAR-2 Regulates Dental Pulp Inflammation Associated with Caries

Protease-activated receptors (PARs) are G-protein-coupled receptors that are activated enzymatically by proteolysis of an N-terminal domain. The cleavage and activation of PARs by serine proteases represent a novel mechanism by which such enzymes could influence the host inflammatory response. The aim of this study was to determine whether PAR-2 expression and activation were increased in dental caries. Using immunohistochemistry, we showed PAR-2 to be localized to pulp cells subjacent to caries lesions, but minimally expressed by healthy pulp tissue. Trypsin and the PAR-2 agonist (PAR2-AP) activated PAR-2 in an in vitro functional assay. Endogenous molecules present in pulp cell lysates from carious teeth specifically activated PAR-2, but those from healthy teeth failed to do so. The activation of PAR-2 in vitro was shown to increase the expression of the pro-inflammatory mediator cyclo-oxygenase-2 (COX-2), providing a mechanism whereby PAR-2 could modulate pulpal inflammation.

Minimal intervention dentistry and older patients Part 1: Risk assessment and caries prevention

Ten million people in the UK today are aged over 65. The latest projections estimate that there will be 5 1/2 million more people aged 65 and older in the next 20 years. This projected pattern of population ageing will have profound consequences for dentistry. Minimal intervention dentistry (MID) is a modern evidence-based approach to caries management in dentate patients that uses the 'medical model' whereby disease is controlled by the 'oral physician'. This approach offers considerable benefits over conventional dentistry for older patients. It encourages patients to be responsible for their oral health through the provision of both knowledge and motivation. MID encompasses risk assessment for dental disease, early detection and control of disease processes, and minimally invasive treatment. 

Clinical Relevance: Risk assessment tools can aid the general dental practitioner and the patient to develop a suitable caries prevention programme for that individual and reduce the need for future operative intervention.

Caries and the older patient

Ageing of the population, together with prolonged retention of teeth, has brought new challenges to dentistry. Whereas in the past oral care for the elderly was restricted to provision of dentures, older patients are now presenting with dental caries and failed restorations. These problems may have an impact on their general health and quality of life. Poor oral hygiene, xerostomia and diet are among the risk factors for caries in older patients and need to be addressed in order to achieve control of the disease. Carious lesions can be treated conservatively in many cases or may need surgical management.

CLINICAL RELEVANCE: Caries is an oral health issue among older patients and can result in tooth loss. Oral health has a great impact on general health and quality of life of elderly people.

Caries incidence following tooth replacement for partially dentate elders

Objective: To compare caries incidence following two different tooth replacement strategies for partially dentate older patients; namely functionally orientated treatment according to the principles of the Shortened Dental Arch (SDA) and conventional treatment using Removable Partial Dentures (RPDs). Method:A randomised controlled clinical trial (RCT) was conducted of partially dentate patients aged 65 years and older. Patients were randomly allocated to two different treatment groups: the RPD group and the SDA group. Each member of the RPD group was restored to complete arches with cobalt-chromium RPDs used to replace missing teeth. Patients in the SDA group were restored to a shortened arch of 10 occluding pairs of natural and replacement teeth using adhesive bridgework. All of the operative treatment was completed by a single operator. Caries incidence was measured over a 2-year period following treatment intervention and recorded using the International Caries and Detection System (ICDAS). Result:In total, 89 patients completed the RCT (45 SDAs and 44 RPDs). Patients in the RPD group recorded a significantly higher incidence of new carious lesions (p<0.001) and recurrent carious lesions (p<0.001) compared to the SDA group. A mixed model of covariance (ANCOVA) revealed that treatment group (p<0.001) and co-morbidity (p<0.001) were significant predictors of caries incidence. Conclusion:Two years after provision of prosthodontic treatment there was a significantly higher incidence of new and recurrent caries lesions in subjects provided with RPDs compared with SDA treatment. This will have a significant impact on the ongoing maintenance costs for these two treatment groups.

Protease activated receptor 2 expression and functionality in caries

Introduction: Protease activated receptors (PARs) are G-protein-coupled transmembrane receptors that are expressed on many cell types and implicated in various inflammatory processes in vivo. The induction of PAR2 as a result of the inflammatory response associated with dental caries remains to be determined. Objectives: The aim was to localise the expression of PAR2 in human dental pulp from carious teeth and to confirm receptor functionality using an in vitro assay. Methods: Dental pulp sections from decalcified carious teeth were examined by immunocytochemsitry. Membrane preparations from cultured pulp fibroblasts were subject to SDS-PAGE and immunoblotting to confirm fibroblast-associated immunoreactivity. The functionality of PAR2 on dental pulp fibroblasts was studied using calcium imaging in the presence of several potential activators including a PAR2 agonist (PAR2-AP), trypsin and pulpal enzymes from a carious tooth. Results: Immunocytochemistry revealed intense PAR2 immunoreactivity on pulpal fibroblasts subjacent to carious lesions but not in surrounding regions of the dental pulp. Pulp specimens from a dental injury model showed no expression of PAR2, suggesting its expression was related to cellular changes associated with ongoing caries. The localisation of PAR2 staining to pulpal fibroblasts in carious teeth was confirmed by Western blotting which revealed PAR2 immunoreactive bands in membrane fractions prepared from pulp fibroblasts. In functional studies, challenge of cultured pupal fibroblasts with PAR2-AP, trypsin and an extract of proteolytic enzymes from a carious dental pulp, showed specific activation of PAR2. Conclusions: This work demonstrates that PAR2 is functional and inducible in human dental pulp fibroblasts in response to caries and that endogenous pulpal enzymes can activate PAR2.

Root caries development in older adults- a prospective cohort study

Objectives: To identify factors associated with root caries development during a two year period in a population of independently living older adults. Methods: A prospective cohort study was carried out with 334 independently living volunteers aged 65 and older. At baseline (t0), each participant completed a questionnaire which recorded age, gender, medical history, fluoride exposure, oral and denture hygiene practices, smoking and alcohol consumption, diet information, and socio economic information. Clinical examinations were performed and stimulated saliva samples were collected. Patients were reviewed 12(t1) and 24(t2) months later to determine the root caries increment. Results: 307 adults were assessed at t1 and 280 were assessed at t2 with 83.8% of participants examined at 24 months. Incidence of root caries in this cohort was 17.4% at t1 and 21.6% at t2. The mean root caries increment was 0.43 (SD 1.45) surfaces at t1 and 0.70 (SD 1.86) surfaces at t2. Age >70 years, completing education at primary level, poor oral hygiene, xerostomia, coronal decay at baseline, higher root caries index at baseline and number of exposed root surfaces showed a statistically significant association (P < 0.05) with root caries development. Conclusion: Root caries is a substantive dental health problem for our older population. Root caries prevention strategies should be targeted at older adults who have poor plaque control and high levels of caries experience. In particular patients with xerostomia should be targeted with preventive measures.

The prevalence of caries in patients referred for orthodontic assessment in Northern Ireland – A retrospective study

Objectives: To determine the prevalence of untreated carious lesions in permanent teeth in patients (under the age of 18) referred for an orthodontic assessment in specialist practice. In addition, the figures shall be compared with national data for Northern Ireland (as outlined in the recent Child Dental Health Survey 2013)
The Gold standard would be that 100% of patients would be caries free upon presentation.

Methods: The clinical records and radiographs (OPT of quality grading 1 or 2) of 337 patients were reviewed. This encompassed patients who had an orthodontic assessment carried out in specialist practice over a 6 month period (following referral from their general dental practitioner)

Results: A total of 337 patient records were examined. Of these, 149 were male (44.2%) and 188 were female (55.8%), with an age range of 7-17 years at the time of new patient assessment. It was found that 36 patients (10.7%) had evidence (clinical and/or radiographic) of active and untreated dental caries. Of those affected, 14 were male and 22 were female.
Breaking the data down in terms of age, we can also get some indication as to how this cohort compares with national data for Northern Ireland :⃰

7-10 years (Mean = 9.3) = 14.3% caries (versus NI average of 6% for 8 year olds)
11-13 years (Mean = 12.1) = 10.1% caries, (versus NI average of 16% for 12 year olds)
14-17 years (Mean = 15.2) = 9.1% caries (versus NI average of 15% for 15 year olds)

⃰using the diagnostic threshold “Decay into dentine (visual dentine caries excluded)”


Conclusion: In this sample group, a total of 10.7% of patients (9.4% of males, 11.7% of females) presented with evidence of undiagnosed caries upon being assessed as a new patient in specialist orthodontic practice. Hence, the gold standard was not met.

Neuropeptide YY1 receptor in human dental pulp cells of noncarious and carious teeth

Aim To determine the distribution of the NPY Y1 receptor in carious and noncarious human dental pulp tissue using immunohistochemistry. A subsidiary aim was to confirm the presence of the NPY Y1 protein product in membrane fractions of dental pulp tissue from carious and noncarious teeth using western blotting. Methodology Twenty two dental pulp samples were collected from carious and noncarious extracted teeth. Ten samples were processed for immunohistochemistry using a specific antibody to the NPY Y1 receptor. Twelve samples were used to obtain membrane extracts which were electrophoresed, blotted onto nitrocellulose and probed with NPY Y1 receptor antibody. Kruskal-Wallis one-way analysis of variance was employed to test for overall statistical differences between NPY Y1 levels in noncarious, moderately carious and grossly carious teeth. Results Neuropeptide Y Y1 receptor immunoreactivity was detected on the walls of blood vessels in pulp tissue from noncarious teeth. In carious teeth NPY Y1 immunoreactvity was observed on nerve fibres, blood vessels and inflammatory cells. Western blotting indicated the presence and confirmed the variability of NPY Y1 receptor protein expression in solubilised membrane preparations of human dental pulp tissue from carious and noncarious teeth. Conclusions Neuropeptide Y Y1 is expressed in human dental pulp tissue with evidence of increased expression in carious compared with noncarious teeth, suggesting a role for NPY Y1 in modulation of caries induced pulpal inflammation. © 2008 International Endodontic Journal.