Impact of prosthodontic rehabilitation on the chewing efficiency of partially dentate older patients

Objectives: This study compared two tooth replacement strategies for partially dentate older patients namely; removable partial dentures (RPDs) and functionally orientated treatment based on the shortened dental arch (SDA) concept. Patients were compared in terms of chewing efficiency after prosthodontic rehabilitation. Methods: Chewing efficiency was assessed electronically by a two-colour gum-mixing test. Specimens were assembled from two different colours of chewing gums with a size of 30 x 18 x 3 mm. After participants chewed for 20 cycles, the gum was retrieved, flattened to a 1-mm-thick wafer, and digitized with a flatbed image scanner. The pixels of unmixed colour in the specimen were counted by means of Adobe Photoshop 2.0R software (Adobe Systems, San Jose, CA, USA), and the ratio to the pixels of the entire frame was computed. This ratio is called the Unmixed Fraction (UF). The more efficiently the specimen is chewed, the less unmixed colour remains, and the smaller the gum becomes. Consequently, a low unmixed fraction corresponds to good chewing efficiency. Results: 32 patients completed the chewing efficiency test (17 RPDs and 15 SDA). The mean UF recorded for the SDA group was not significantly different to that recorded for the RPD group (p>0.05, unpaired t-test). Conclusion: These results indicate that prosthodontic rehabilitation according to the principles of the SDA is equivalent to RPDs in terms of restoration of chewing ability for partially dentate older patients.

Relationships between Oral Health and Nutritional Status of Older Adults

Objectives: The World Health Organisation has highlighted the paucity of research into the oral health needs of older adults. In particular, the relationships between oral health and nutritional status require further investigation and analysis. This study aimed to describe some of the relationships between the number of remaining occluding tooth contacts, oral health related quality of life and nutritional status of partially dentate older adults.

Methods: 45 partially dentate patients aged 65 years and older were recruited to the study after visiting a university dental hospital. An initial dental examination charted the remaining teeth including the number of occluding contacts. Oral health related quality of life was recorded using the 14 item Oral Health Impact Profile. Nutritional status was measured using the Mini Nutritional Assessment (MNA) in addition to biochemical analysis of a haematological sample. Correlation between data values was measured using a Pearson's correlation coefficient (r).

Results: The patient sample was made up of 44% males and 56% females with a mean age of 72.4 years (range 65-84 years). With increasing age the patients' oral health related quality of life scores improved. (r=-0.25) Within the sample the number of occluding tooth contacts ranged from 6 to 11. It was found that as the number of occluding contacts increased, better oral health related quality of life scores were recorded. (r=-0.30) Generally mini nutritional assessment scores improved with increasing numbers of tooth contacts. (r=0.14) In addition, as the number of occluding teeth contacts increased total lymphocyte count (r=0.35), vitamin B12 (r=0.22) and serum folate (r=0.06) all increased.

Conclusions: In older patients increased numbers of tooth contacts are associated with better oral health related quality of life. Increasing numbers of occluding contacts are also associated with better MNA scores and some haematological indicators of nutritional status.

Aesthetic Perceptions - Is There a Difference?

Introduction: In recent times, the demand for aesthetic dentistry has increased, with patients presenting for treatment expecting an improvement in their aesthetics. Therefore, it is increasingly important for the dental profession to appreciate perceptions of dental aesthetics in order to provide a patient-centred service.

Objectives: The aim of this study is to quantify perceptions of aesthetics using a cross-sectional survey design. The hypotheses being tested were that differences exist in aesthetic perceptions of 1) dentists and dental students, 2) different age ranges and 3) gender.

Methods: A questionnaire was distributed to dental staff and students in the Cork University Dental School and Hospital. The questionnaire sought information relating to aesthetic perceptions by asking participants to compare photographs of smiles.

Results: 100 questionnaires were returned. It was found that differences existed in perceptions of dentists and dental students when certain aspects of a smile were evaluated, in particular when a minor flaw was present in a smile in addition to the major flaw being tested. Assuming that flaws were detected, more dental students (34%) than dentists (26%) were found to prioritise colour above more subtle flaws, such as a centreline shift. However, most results between the two groups are comparable in terms of their prioritising of importance of particular aspects of a smile, with no large significant differences.

Conclusion: Differences exist in aesthetic perceptions of dentists and dental students, especially with regard to tooth colour.

The design and psychometric assessment of a TPB-based questionnaire suitable for use with primary school children

Despite the popularity of the Theory of Planned Behaviour (TPB) a lack of research assessing the efficacy of the model in understanding the health behaviour of children exists, with those studies that have been conducted reporting problems with questionnaire formulation and low to moderate internal consistencies for TPB constructs. The aim of this study was to develop and test a TPB-based measure suitable for use with primary school children aged 9 to 10 years. A mixed method sequential design was employed. In Stage 1, 7 semi-structured focus group discussions (N=56) were conducted to elicit the underlying beliefs specific to tooth brushing. Using content thematic analysis the beliefs were identified and a TPB measure was developed. A repeated measures design was employed in Stage 2 using test re-test reliability analysis in order to assess its psychometric properties. In all, 184 children completed the questionnaire. Test-retest reliabilities support the validity and reliability of the TPB measure for assessing the tooth brushing beliefs of children. Pearson’s product moment correlations were calculated for all of the TPB beliefs, achieving substantial to almost perfect agreement levels. Specifically, a significant relationship between all 10 of the direct and indirect TPB constructs at the 0.01 level was achieved. This paper will discuss the design and development of the measure so could serve as a guide to fellow researchers and health psychologists interested in using theoretical models to investigate the health and well-being of children.

Fasciola hepatica:the effect of the microtubule inhibitors colchicine and tubulozole-C on the ultrastructure of the adult fluke

The effect of the microtubule inhibitors colchicine (1 x 10(-3) M) and tubulozole-C(1 x 10(-6) M) on the ultrastructure of adult Fasciola hepatica has been determined in vitro by transmission electron microscopy (TEM), using both intact flukes and tissue-slice material. With colchicine treatment, the apical membrane of the tegument became increasingly convoluted and blebbed, while accumulations of T1 secretory bodies occurred in the basal region of the syncytium, leading to progressively fewer secretory bodies in the syncytium. In the tegumental cells there were distinct accumulations of T1 secretory bodies around the Golgi complexes, which remained active for up to 12 h incubation. Tubulozole-treated flukes showed more severe effects, with initial accumulations of secretory bodies, both at the tegumental apex and base. This was followed in the later time-periods by the sloughing of the tegumental syncytium. In the underlying tegumental cells, the granular endoplasmic reticulum (GER) cisternae were swollen and disrupted, becoming concentrated around the nucleus. The Golgi complexes were dispersed to the periphery of the cells and gradually disappeared from the cytoplasm. After treatment with both drugs, the cell population in the vitelline follicles was altered, with an abnormally large proportion of stem cells and relatively few intermediate type 1 cells. The nurse cell cytoplasm became fragmented and was no longer in contact with the vitelline cells, while the shell globule clusters within the intermediate type 2 and mature cells were loosely packed. In the mature vitelline cells, 'yolk' globules and glycogen deposits became fewer than normal and lipid droplets were observed. The results are discussed in relation to the different modes of action of the two drugs and potential significance of this to anthelmintic (benzimidazole) therapy.

Sector analysis provides additional spatial information on the permanent prostate brachytherapy learning curve

PURPOSE: To evaluate the permanent prostate brachytherapy (PPB) learning curve using postimplant multisector dosimetric analysis and to assess the correlation between sector -specific dosimetry and patient-reported outcome measures (PROMs).

METHODS AND METHODS: First 200 patients treated with (125)I PPB monotherapy (145 Gy) at a single institution were assessed. Postimplant dosimetry (PID) using CT was evaluated for whole prostate (global) and 12 sectors, assessing minimum dose to 90% of prostate (D90) and dose to 0.1 cm(3) of rectum (D0.1cc). Global and sector PID results were evaluated to investigate changes in D90 with case number. Urinary and bowel PROMs were assessed using the International Prostate Symptom Score and the Expanded Prostate Cancer Index Composite questionnaire. The correlation between global and individual sector PID and urinary/bowel PROMs was also evaluated.

RESULTS: Linear regression confirmed a significant improvement in global D90 with case number (r(2) = 0.20; p = 0.001) at a rate of 0.11 Gy/case. Postimplant D90 of base sectors increased at a rate of 0.11-0.15 Gy/case (p = 0.0001) and matched global improvement. The regression lines of midgland and apex sectors were significantly different from global D90 (p = 0.01). Posterior midgland sectors showed a significant reduction in D90 with case number at a rate of 0.13-0.19 Gy/case (p = 0.01). Dose to posterior midgland sectors correlated with rectal D0.1cc dose but not bowel PROMs. Dose to posterior midgland sectors correlated with urinary International Prostate Symptom Score change, which was not apparent when global D90 alone was considered.

CONCLUSIONS: Sector analysis provided increased spatial information regarding the PPB learning curve. Furthermore, sector analysis correlated with urinary PROMs and rectal dose.

Investigating Intra-individual Dietary Changes and Radiocarbon Ages Using High Resolution δ13C, δ15N Isotope Ratios and 14C Ages Obtained From Dentine Increments

Ten medieval permanent teeth were subjected to incremental dentine sectioning and stable isotope analysis to investigate dietary changes in high resolution. In addition to this, eight increments were also selected for 14C measurements to examine possible intra-individual age differences. Results reveal the cessation of weaning, various dietary profiles and in some cases significantly different 14C ages obtained from a single tooth. This case study illustrates how 14C measurements can function as a proxy alongside the commonly used carbon and nitrogen stable isotope values to interpret the diet of past individuals

A systematic review and meta-analysis of the survival of feldspathic porcelain veneers over 5 and 10 years

PURPOSE: This systematic review reports on the survival of feldspathic porcelain veneers.

MATERIALS AND METHODS: The Cochrane Library, MEDLINE (OVID), Embase, Web of Knowledge, selected journals, clinical trials registers, and conference proceedings were searched independently by two reviewers. Academic colleagues were also contacted to identify relevant research. Inclusion criteria were human cohort studies (prospective and retrospective) and controlled trials assessing outcomes of feldspathic porcelain veneers in more than 15 patients and with at least some of the veneers in situ for 5 years. Of 4,294 articles identified, 116 studies underwent full-text screenings and 69 were further reviewed for eligibility. Of these, 11 were included in the qualitative analysis and 6 (5 cohorts) were included in meta-analyses. Estimated cumulative survival and standard error for each study were assessed and used for meta-, sensitivity, and post hoc analyses. The I2 statistic and the Cochran Q test and its associated P value were used to evaluate statistical heterogeneity, with a random-effects meta-analysis used when the P value for heterogeneity was less than .1. Galbraith, forest, and funnel plots explored heterogeneity, publication patterns, and small study biases.

RESULTS: The estimated cumulative survival for feldspathic porcelain veneers was 95.7% (95% confidence interval [CI]: 92.9% to 98.4%) at 5 years and ranged from 64% to 95% at 10 years across three studies. A post hoc meta-analysis indicated that the 10-year best estimate may approach 95.6% (95% CI: 93.8% to 97.5%). High levels of statistical heterogeneity were found.

CONCLUSIONS: When bonded to enamel substrate, feldspathic porcelain veneers have a very high 10-year survival rate that may approach 95%. Clinical heterogeneity is associated with differences in reported survival rates. Use of clinically relevant survival definitions and careful reporting of tooth characteristics, censorship, clustering, and precise results in future research would improve metaanalytic estimates and aid treatment decisions.

Oral rehabilitation for partially dentate elders: a qualitative analysis

Aims: This study aimed to gain insight into patient’s perceptions of natural tooth loss and explored their experiences of oral rehabilitation according to a functionally orientated approach (SDA) and Removable Partial Dentures (RPD).
Study Design: For this qualitative study, a purposive sample of 15 partially dentate older patients
were recruited from Cork Dental School and Hospital. These patients had previously participated in a randomised controlled clinical trial (RCT) where they were provided with either SDA treatment using adhesive bridgework or provided with Cobalt Chromium framework RPDs. In- depth interviews were undertaken and thematic analysis was utilised to interpret the data.
Results: The findings of this study indicated strong satisfaction with SDA treatment. Patients referred to the ease in which they adapted to the adhesive prostheses as they were “lightweight”, “neat” and “fixed”. Irrespective of treatment option, patients indicated that they felt
their new prostheses were durable and an improvement on previous treatments. Most patients indicated that, previous to the RCT, they had not attended a general dentist for a number of years and only then for acute issues. They had concerns that treatment which was provided to them as part of the RCT would not be available to them in primary care. Interestingly, although they do not want their condition to dis-improve, if their prostheses failed they stated that they would not seek alternative treatment but would revert back
to adopting previous coping mechanisms.
Conclusion: This study illustrates that partially dentate older patients were very satisfied with oral rehabilitation according to a functionally orientated approach. Unfortunately they did not believe that this treatment would currently be made available to them in a primary care setting.

Comparison of Composite Placement Techniques by Recently Qualified Dental Practitioners.

Objectives: To evaluate the placement of composite materials by new graduates using three alternative placement techniques.Methods: A cohort of 34 recently qualified graduates were asked to restore class II interproximal cavities in plastic teeth using three different techniques.

(i) A conventional incremental filling technique (Herculite XRV) using increments no larger than 2-mm with an initial layer on the cervical floor of the box of 1-mm.
(ii) Flowable bulk fill technique (Dentsply SDR) bulk fill placement in a 3-mm layer followed by an incremental fill of a microhybrid resin
(iii) Bulk fill (Kerr Sonicfill) which involved restorations placed in a 5-mm layer.

The operators were instructed in each technique, didactically and with a hands-on demonstration, prior to restoration placement.
All restorations were cured according to manufacturer’s recommendations. Each participant restored 3 teeth, 1 tooth per treatment technique.
The restorations were evaluated using modified USPHS criteria to assess both the marginal adaptation and the surface texture of the restorations. Blind evaluations were carried out independently by two examiners with the aid of magnification (loupes X2.5). Examiners were standardized prior to evaluation.
Results: Gaps between the tooth margins and the restoration or between the layers of the restoration were found in 13 of Group (i), 3 of Group (ii), and 4 of Group (iii)
Statistical analysis revealed a significant difference between the incrementally filled group (i) and the flowable bulk-fill group (ii) (p=0.0043) and between the incrementally filled (i) and the bulk fill groups (iii) (p=0.012) and no statistical difference (p=0.69) between the bulk filled groups Conclusions: Bulk fill techniques may result in a more satisfactory seal of the cavity margins when restoring with composite.

The welfare implications of large litter size in the domestic pig II:Management factors

Increasing litter size has long been a goal of pig (Sus scrofa domesticus) breeders and producers in many countries. Whilst this has economic and environmental benefits for the pig industry, there are also implications for pig welfare. Certain management interventions are used when litter size routinely exceeds the ability of individual sows to successfully rear all the piglets (ie viable piglets outnumber functional teats). Such interventions include: tooth reduction; split suckling; cross-fostering; use of nurse sow systems and early weaning, including split weaning; and use of artificial rearing systems. These practices raise welfare questions for both the piglets and sow and are described and discussed in this review. In addition, possible management approaches which might mitigate health and welfare issues associated with large litters are identified. These include early intervention to provide increased care for vulnerable neonates and improvements to farrowing accommodation to mitigate negative effects, particularly for nurse sows. An important concept is that management at all stages of the reproductive cycle, not simply in the farrowing accommodation, can impact on piglet outcomes. For example, poor stockhandling at earlier stages of the reproductive cycle can create fearful animals with increased likelihood of showing poor maternal behaviour. Benefits of good sow and litter management, including positive human-animal relationships, are discussed. Such practices apply to all production situations, not just those involving large litters. However, given that interventions for large litters involve increased handling of piglets and increased interaction with sows, there are likely to be even greater benefits for management of hyper-prolific herds. © 2013 Universities Federation for Animal Welfare.

Occlusal considerations in periodontics

Periodontal disease does not directly affect the occluding surfaces of teeth, consequently some may find a section on periodontics a surprising inclusion. Trauma from the occlusion, however, has been linked with periodontal disease for many years. Karolyi published his pioneering paper, in 1901 'Beobachtungen uber Pyorrhoea alveolaris' (occlusal stress and 'alveolar pyorrhoea'). (1) However, despite extensive research over many decades, the role of occlusion in the aetiology and pathogenesis of inflammatory periodontitis is still not completely understood.

TNF-α Sensitizes Mechanoreceptors in Human Odontoblasts

Background: Mechanotransduction in the dental pulp is mediated by mechano-sensitive trigeminal afferents but accumulating evidence suggests odontoblasts also contribute to mechano-sensory functions of the pulp as evidenced by expression of TRP channels, calcium-activated potassium channels and TREK-1 potassium channels. Activation of these mechano-sensitive channels is considered critical for the mechanotransduction of fluid movement within dentinal tubules into electrical signals transmitted by the pulpal afferents to elicit tooth sensitivity and pain. Since tooth pain and sensitivity are potentiated by inflammation we hypothesise that the inflammatory cytokine TNF-α sensitizes odontoblast responses to mechanical stimuli. Objective: To investigate the effect of TNF-α on the response of odontblast-like cells to mechanical stimuli. Method: Odontoblast-like cells were derived from dental pulp cells of immature third molars as previously described (El-karim et al 20112011 Pain, 152, 2211-2223). Odontoblast response to mechanical stimuli (application of hypotonic solution) was determined using ratiometric calcium imaging. Cells were treated with TNF-α for either 24hrs or short application for 10 mins prior to calcium imaging. Result: Odontoblast-like cells responded to hypotonic solution (230 mOSM) by increase in cytoplasmic Ca2+ concentration [Ca+2]i that was reduced to near base line in the presence of the TRPV4 antagonist RN-1734. Incubation of odontoblast -like cells with TNFα for 24 hrs resulted in a significant increase in cytoplasmic Ca2+ concentration in response to hypotonic stimuli compared to untreated cells. Similar results were obtained when cells were treated with TNF-α for 10 mins prior to imaging. Conclusion: Both short and long term treatment of odontoblasts-like cells with TNF-α resulted in enhanced responses to mechanical stimuli mediated via TRPV4 channel suggesting a role for this channel in inflammatory dental pain.

Functional expression of thermo-sensitive TRP channels in human odontoblasts

Introduction: Accumulating evidence supports a role for odontoblasts in initiating tooth pain, however direct ionic mechanisms underlying dentine nociceptive function remain unclear. The transient receptor potential (TRP) ion channels are directly related to cellular mechanisms of nociception and thermo-sensitive function but their expression by human odontoblasts remains to be determined. Objectives: To investigate the expression and functionality of the thermo-sensitive TRP channels TRPV1, TRPV4, TRPM8 and TRPA1 in human odontoblasts. Methods: Human odontoblasts were derived from dental pulp of immature permanent third molars by explant method. Cell lysates of odontoblasts were subject to SDS- polyacrylamide gel electrophoresis and proteins were blotted onto nitrocellulose membranes. Blots were probed with primary antibodies to TRPA1, TRPM8, TRPV4 and TRPV1. Detection of bound primary antibodies was achieved using appropriate anti-species antibody conjugates and chemiluminescent substrates. Functionality of the channels was determined with Ca2+ microfluorimetry, where cells grown in cover slips and incubated with Fura 2AM prior to stimulation with capsaicin (TRPV1 agonist), 4 alpha-phorbol 12,13-didecanoate (4áPDD) (TRPV4 agonist), icilin (TRPA1 agonist) and menthol (TRPM8 agonist). Emitted fluorescence was measured and the fluorescence ratio (R) was calculated as F340/F380 to determine the level of [Ca2+]i. Results: Western blotting confirmed the molecular localisation of thermo-sensitive TRP channels in human odontoblasts. Functionality assays revealed increase in [Ca2+]i in response to capsacin, icillin, methanol and 4áPDD indicating functional expression of TRPV1, TRPA1, TRPM8 and TRPV4 respectively. Conclusions: Functional expression of thermo-sensitive TRP channels in human odontoblasts may indicate a crucial role for odontoblasts in thermally induced dental pain. (Supported by a Research Grant from the Royal College of Surgeons of Edinburgh)

Neuropeptides regulate expression of angiogenic growth factors in pulpal fibroblasts

In the dental pulp angiogenesis is crucial for tooth development and a prerequisite for successful repair following injury and inflammation. The role of neuropeptides in pulpal inflammation has been well documented but their role in the regulation of angiogenesis in the dental pulp has not been elucidated. Objectives: The aim was to profile the expression of angiogenic growth factors produced by pulp fibroblasts and to study the effects of neuropeptides on their expression. Methods: Human pulp fibroblasts derived from healthy molar teeth were stimulated with neuropeptides previously identified in dental pulp, namely, Substance P (SP), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and calcitonin related gene peptide (CGRP) for 24 and 48 hrs. Simultaneous expression of ten growth factors was quantified using a novel human angiogenesis array (Ray Biotech, USA). Results: Pulp fibroblasts expressed human angiogenic growth factors, VEGF, bFGF, PDGF-BB, HGF, ANG2, HB-EGF, PIGF, angiogenin and leptin. Among the growth factors expressed VEGF, angiogenin and HGF were abundantly expressed compared to others. Neuropeptides induced variable effects on the expression of the angiogenic factors: CGRP potently up-regulated VEGF, bFGF, HGF and PIGF after 24 hr, while NPY tended to down regulate growth factors after 24 hr in culture but markedly up regulated ANG2, bFGF and leptin after 48 hr. SP down regulated expression of all angiogenic growth factors except for leptin, while VIP induced a small increase in expression of each growth factor, irrespective of time. Conclusion: Pulp fibroblasts express a range of angiogenic growth factors including angiogenin and leptin. Neuropeptides regulate the expression of these factors, suggesting an additional role for neuropeptides in the regulation of inflammation and healing in the dental pulp.
This work is supported by TC White Research Fund