Tooth surface loss: an overview

Perception of oral health related quality of life and orofacial aesthetics following restorative treatment of tooth wear: A five-year follow-up

OBJECTIVES

Non-carious tooth wear often has a multifactorial etiology and may lead to functional or aesthetically related problems. The most common complaints associated with tooth wear are dissatisfaction with dental appearance and a negative impact on the experienced Oral Health Related Quality of Life (OHRQoL). The aim of this study was to investigate the change in OHRQoL and the perception of aesthetics, following restorative treatment of moderate to severe tooth wear patients, with a five-year follow-up.

METHODS

An explorative study, based on prospective data, was performed. OHRQoL and the perception of aesthetics were measured with the OHIP-NL and OES-NL. These questionnaires were completed before treatment, one month after treatment, and at 1-, 3- and 5-years post-treatment. Treatment involved full mouth reconstruction with composite resin restorations. The data was analysed as repeated measures by using a linear mixed-effects model.

RESULTS

One hundred and twenty-three tooth wear patients that received restorative rehabilitation were included (97 males, 26 females, 37.5 ± 8.8 years-old). Data showed a statistically significant increase in both experienced OHRQoL and orofacial appearance after restorative treatment. The OHIP-scores remained stable over time, while the OES-scores slightly decreased during the years after treatment. Regarding the seven domains of the OHIP, the largest difference in OHIP-score was found in the domain of 'Psychological Discomfort'. The mean overall OHIP-score was 1.8 at baseline and 1.3 at the 5-years recall. The mean OES score increased from 41.8 at baseline to 66.1 at the 5-years follow-up.

CONCLUSIONS

Tooth wear patients reported significant improvements in their OHRQoL and their perception of orofacial aesthetics after restorative treatment. This increase remained at least five years post-treatment.

CLINICAL SIGNIFICANCE

The clinical impact of restorative treatment for tooth wear patients is considerable. This paper emphasizes the need to include a discussion of the patient related outcome measures when planning care.

Where Is the Artificial Intelligence Applied in Dentistry? Systematic Review and Literature Analysis

This literature research had two main objectives. The first objective was to quantify how frequently artificial intelligence (AI) was utilized in dental literature from 2011 until 2021. The second objective was to distinguish the focus of such publications; in particular, dental field and topic. The main inclusion criterium was an original article or review in English focused on dental utilization of AI. All other types of publications or non-dental or non-AI-focused were excluded. The information sources were Web of Science, PubMed, Scopus, and Google Scholar, queried on 19 April 2022. The search string was “artificial intelligence” AND (dental OR dentistry OR tooth OR teeth OR dentofacial OR maxillofacial OR orofacial OR orthodontics OR endodontics OR periodontics OR prosthodontics). Following the removal of duplicates, all remaining publications were returned by searches and were screened by three independent operators to minimize the risk of bias. The analysis of 2011–2021 publications identified 4413 records, from which 1497 were finally selected and calculated according to the year of publication. The results confirmed a historically unprecedented boom in AI dental publications, with an average increase of 21.6% per year over the last decade and a 34.9% increase per year over the last 5 years. In the achievement of the second objective, qualitative assessment of dental AI publications since 2021 identified 1717 records, with 497 papers finally selected. The results of this assessment indicated the relative proportions of focal topics, as follows: radiology 26.36%, orthodontics 18.31%, general scope 17.10%, restorative 12.09%, surgery 11.87% and education 5.63%. The review confirms that the current use of artificial intelligence in dentistry is concentrated mainly around the evaluation of digital diagnostic methods, especially radiology; however, its implementation is expected to gradually penetrate all parts of the profession.

The consequences of living with a severe malocclusion: A review of the literature

AIM

To facilitate the orthognathic shared decision-making process by identifying and applying existing research evidence to establish the potential consequences of living with a severe malocclusion.

METHODS

A comprehensive narrative literature review was conducted to explore the potential complications of severe malocclusion. A systematic electronic literature search of four databases combined with supplementary hand searching identified 1024 articles of interest. A total of 799 articles were included in the narrative literature review, which was divided into 10 themes: Oral Health Related Quality Of Life; Temporomandibular Joint Dysfunction; Masticatory Limitation; Sleep Apnoea; Traumatic Dental Injury; Tooth Surface Loss; Change Over Time; Periodontal Injury; Restorative Difficulty; and Functional Shift and Dual Bite. A deductive approach was used to draw conclusions from the evidence available within each theme.

RESULTS

The narrative literature review established 27 conclusions, indicating that those living with a severe malocclusion may be predisposed to a range of potential consequences. With the exception of Oral Health Related Quality Of Life, which is poorer in adults with severe malocclusion than those with normal occlusions, and the risk of Traumatic Dental Injury, which increases when the overjet is >5 mm in the permanent and 3 mm in the primary dentition, the evidence supporting the remaining conclusions was found to be of low to moderate quality and at high risk of bias.

CONCLUSION

This article summarises the findings of a comprehensive narrative literature review in which all of the relevant research evidence within a substantive investigative area is established and evaluated. Notwithstanding limitations regarding the quality of the available evidence; when combined with clinical expertise and an awareness of individual patient preferences, the conclusions presented may facilitate the orthognathic shared decision-making process and furthermore, may guide the development of the high-quality longitudinal research required to validate them.

The design, development, and calibration of cervical abrasion index of treatment needs probe for measurement of cervical abrasion

Context:

Although a common dental problem, there are no simple instruments or reliable methods to measure cervical abrasion.

Aim:

To study the design, development, calibration, efficacy, and compliance of usage of a novel Cervical Abrasion Index of Treatment Need (CAITN) probe to measure cervical abrasion.

Settings and Design:

The ex-vivo study was conducted as a part of comprehensive study for the development of standardized CAITN probe and index with a standard methodology for recording the abrasion.

Materials and Methods:

The compliance and usage of the probe were assessed by a standardized set of questionnaires to the interns followed by an ex-vivo study in 100 subjects. Gold standard comparisons with Vernier caliper, inter-examiner, and intra-examiner reliability were analyzed using SPSS.

Results:

Data from the questionnaire indicate that 100% of examiners had no difficulty in handling the instrument or measuring and reading the values. Comparison between the CAITN probe and the gold standard was statistically significant indicating a correlation for cervical abrasion measurement between the two methods (p < 0.001). The mean difference between the two measurements using the CAITN probe and gold standard method was calculated with paired t-test and was insignificant (p > 0.05). High statistical significant correlation was also found for intra-examiner and inter-examiner reliability measurement of CAITN probe (p < 0.001).

Conclusion:

The design and structure of the CAITN probe are standardized with a fair gold standard comparison and that the novel probe can be used as an effective tool to measure the depth of cervical abrasion and its treatment needs.

Rehardening and the Protective Effect of Gamma-Polyglutamic Acid/Nano-Hydroxyapatite Paste on Surface-Etched Enamel

Many revolutionary approaches are on the way pertaining to the high occurrence of tooth decay, which is an enduring challenge in the field of preventive dentistry. However, an ideal dental care material has yet to be fully developed. With this aim, this research reports a dramatic enhancement in the rehardening potential of surface-etched enamels through a plausible synergistic effect of the novel combination of γ-polyglutamic acid (γ-PGA) and nano-hydroxyapatite (nano-HAp) paste, within the limitations of the study. The percentage of recovery of the surface microhardness (SMHR%) and the surface parameters for 9 wt% γ-PGA/nano-HAp paste on acid-etched enamel were investigated with a Vickers microhardness tester and an atomic force microscope, respectively. This in vitro study demonstrates that γ-PGA/nano-HAp treatment could increase the SMHR% of etched enamel to 39.59 ± 6.69% in 30 min. To test the hypothesis of the rehardening mechanism and the preventive effect of the γ-PGA/nano-HAp paste, the surface parameters of mean peak spacing (Rsm) and mean arithmetic surface roughness (Ra) were both measured and compared to the specimens subjected to demineralization and/or remineralization. After the treatment of γ-PGA/nano-HAp on the etched surface, the reduction in Rsm from 999 ± 120 nm to 700 ± 80 nm suggests the possible mechanism of void-filling within a short treatment time of 10 min. Furthermore, ΔRa-I, the roughness change due to etching before remineralization, was 23.15 ± 3.23 nm, while ΔRa-II, the roughness change after remineralization, was 11.99 ± 3.90 nm. This statistically significant reduction in roughness change (p < 0.05) implies a protective effect against the demineralization process. The as-developed novel γ-PGA/nano-HAp paste possesses a high efficacy towards tooth microhardness rehardening, and a protective effect against acid etching.

McNamara's Fallacies in Dentistry. 2: Tooth Surface Loss Fallacies

Given the number of perceived myths and fallacies in relation to tooth substance loss, this article seeks to address these using a wide variety of clinical cases as examples and by way of scientific references.

CPD/Clinical Relevance: The incidence of tooth wear is increasing, so an understanding of the myths and truths surrounding its treatment is valuable.

Quantify the Protein-Protein Interaction Effects on Adsorption Related Lubricating Behaviors of α-Amylase on a Glass Surface

Dental ceramic material is one of the widely preferred restorative materials to mimic the natural tooth enamel surface. However, it has continuously been degraded because of low wear resistance during mastication in the oral cavity. The friction involved was reduced by introducing the lubricant saliva protein layers to improve the wear resistance of the dental materials. However, little is understood regarding how the protein-protein interactions (PPI) influence the adsorbed-state structures and lubricating behaviors of saliva proteins on the ceramic material surface. The objective of this study is to quantify the influences of PPI effects on the structural changes and corresponding oral lubrications of adsorbed α-amylase, one of the abundant proteins in the saliva, on the dental ceramic material with glass as a model surface. α-Amylase was first adsorbed to glass surface under varying protein solution concentrations to saturate the surface to vary the PPI effects over a wide range. The areal density of the adsorbed protein was measured as an indicator of the level of PPI effects within the layer, and these values were then correlated with the measurements of the adsorbed protein's secondary structure and corresponding friction coefficient. The decreased friction coefficient value was an indicator of the lubricated surfaces with higher wear resistance. Our results indicate that PPI effects help stabilize the structure of α-amylase adsorbed on glass, and the correlation observed between the friction coefficient and the conformational state of adsorbed α-amylase was apparent. This study thus provides new molecular-level insights into how PPI influences the structure and lubricating behaviors of adsorbed protein, which is critical for the innovations of dental ceramic material designs with improved wear resistance.

Effect of Commonly Consumed Beverages on Microhardness of Two Types of Composites

Objective

The objective of the present in vitro study was to assess the influence of commonly consumed beverages on the microhardness of microhybrid and nanofilled composite resins.

Materials and methods

Two hundred and forty cylindrical specimens were produced using circular aluminum molds of an internal diameter of 10 mm and a thickness of 2 mm, 120 samples each from microhybrid composite (Filtek Z250, 3M, ESPE, USA) and nanofilled composite (filtek Z250, 3M, ESPE, USA). They were divided into 4 subgroups of 30 specimens each. These specimens were immersed in distilled water, tea, coffee, and cola drink, respectively. Microhardness was calculated using Vickers microhardness tester (MMT-X7 Matsuzawa, Japan). Data were statistically analyzed using paired t-test and one-way analysis of variance (ANOVA) using Tukey’s correction was used for multiple subgroup comparison.

Results

Microhardness of both the composites reduced after immersing in different beverages compared to water. Nanofilled composites showed more change in microhardness than microhybrid composite. Cola caused a significant reduction in microhardness followed by coffee, tea, and water.

Conclusion

The beverages used have negative effects on the hardness of both the type of composites. The surface microhardness of nanofilled composite is significantly reduced when immersed in carbonated beverages like cola.

How to cite this article

Barve D, Dave PN, Gulve MN, et al. Effect of Commonly Consumed Beverages on Microhardness of Two Types of Composites. Int J Clin Pediatr Dent 2020;13(6):663–667.

Patient perceptions of healthy weight promotion in dental settings

INTRODUCTION

Excess weight is a risk factor for systemic and oral diseases. Since dental professionals are already involved in imparting overall health messages when certain conditions impact oral health, it should make sense that they also deliver related health messages such as promoting the maintenance of healthy weight for patients.

OBJECTIVES

This study evaluated the perceptions of adult patients attending private dental clinics on healthy weight promotion by dental professionals.

METHODS

A cross-sectional multicenter survey was designed and set in four private dental clinics (London/Hampshire) between April and July 2015. All eligible patients (≥ 18 years) completed a questionnaire. Body Mass Index (BMI; kg/m²) was calculated from height and weight measurements. Questionnaire content was centred on patient perceptions of 6 domains with the primary domain as to whether patients would accept healthy weight promotion by dental professionals.

RESULTS

213 adults (aged 20-85 years) participated in this study and 58.2% were females. Although the overwhelming majority endorsed healthy weight promotion by the dental team, the overweight/obese were significantly more sensitive (BMI screening χ2 trend = 6.840, p = 0.009; healthy weight information χ2 trend = 6.231, p = 0.013). Awareness of risk of periodontitis, carcinoma and overall adverse health outcomes associated with overweight or obesity was low.

CONCLUSION

The study cohort was well primed for healthy weight advice. Routine healthy weight promotion and BMI screening should be considered in the private dental clinic settings.

CLINICAL SIGNIFICANCE

This is an opportunity to collaborate with other health care professionals to support overall health monitoring/advice; a common risk factor strategy as recommended by the WHO. Future research is merited for this new initiative particularly perceptions of: dental teams' on healthy weight management, longitudinal interventions, NHS, children/parents and separate obese groups.

Influence of Er,Cr:YSGG laser, associated or not to desensitizing agents, in the prevention of acid erosion in bovine root dentin

This in vitro study evaluated the influence of the Er,Cr:YSGG laser, associated or not to desensitizing agents, in the prevention of acid erosion in bovine root dentin. Eighty dentin specimens were selected and divided into eight groups (n = 10): G1: negative control; G2: positive control (5% fluoride varnish-FV); G3: Er,Cr:YSGG laser; G4: FV + laser; G5: 3% potassium oxalate; G6: 3% potassium oxalate + laser; G7: biphasic calcium silicate/phosphate gel (gel); G8: gel + laser. Laser parameters: 0.5 W, 6.25 J/cm² at 1-mm distance. The erosive drink used was a cola soft-drink (pH = 2.42 at 4 °C), lasting 5 min, twice a day, with 6-h intervals between the challenges, during 14 days. Kolmogorov-Smirnov and Levene's tests were satisfied. The surface roughness data were submitted to ANOVA and Tukey post hoc tests. For the wear profile, Kruskal-Wallis and Dunn post hoc tests were used. Afterwards, the Spearman correlation test was performed. All statistical tests assumed a significance level of 5% (α = 0.05). G1 presented the highest surface roughness value after the erosive challenge (3.586 μm² ± 0.205 μm²) and the G7 presented the lowest surface roughness value after the erosive challenge (1.071 μm² ± 0.180 μm²). For the lost volume, G4 presented the lowest percentage (9.7% ± 0.9%), while G1 had the highest percentage (41.8% ± 2.5%), both with p < 0.05. There was a weak correlation between the response variables (ρ = 0.33). All groups presented lower values of surface roughness and loss of volume when compared to the negative control group. For the surface roughness, the biphasic calcium silicate/phosphate gel presented the best result. For volume loss, the 5% fluoride varnish + Er,Cr:YSGG laser showed the best results compared to the other groups.

The influence of management of tooth wear on oral health-related quality of life

Objective

The purpose of this study was to identify the level of oral health-related quality of life and orofacial appearance in patients with moderate to severe tooth wear. Patients with and without a request for restorative treatment were included.

Methods

One hundred twenty-four patients (98 men, 26 women, mean age: 40.5 ± 8.8 years) with moderate to severe tooth wear were included. Patients without a request for help received a non-restorative treatment of counseling and monitoring. Patients with a request for restorative treatment were treated with a full rehabilitation using composite resin restorations. Oral Health Impact Profile (OHIP-NL) and Orofacial Esthetic Scale (OES-NL) questionnaires were filled in at baseline and after 1 year.

Results

Counseling and monitoring group: baseline OHIP-NL score was 0.4 ± 0.3, baseline summary score of OES-NL was 48 ± 7.0, and baseline impression score was 7.1 ± 1.2. Scores had not changed significantly after 1 year (p = 1.00 after Bonferroni correction).Restoration group: baseline OHIP-NL score was 0.8 ± 0.6, baseline summary score of OES-NL was 38 ± 10, and baseline impression score was 5.9 ± 1.5. Scores had improved significantly after 1 year (p < 0.001 after Bonferroni correction).

Conclusions

Counseling and monitoring did not result in a significant deterioration and restorative treatment resulted in a significant improvement of oral health-related quality of life (OHRQoL) and orofacial appearance in this patient group.

Clinical significance

In patients with moderate to severe tooth wear, without functional and esthetical problems, counseling and monitoring may be an appropriate treatment option. Restorative treatment in patients with a need for treatment results in an improved OHRQoL. OHIP and OES questionnaires may be used to monitor changes in clinically relevant symptoms.

Establishing the Effect of Brushing and a Day's Diet on Tooth Tissue Loss in Vitro

To develop an in vitro model to mimic the effects of meals equivalent to a day’s diet on tooth tissue loss (TTL). To identify how diet effects tooth wear and to test the efficacy of dental products designed to reduce tooth wear in a more realistic environment. A typical Friday diet was devised comprising: Breakfast then brushing, lunch, dinner then brushing. Groups of enamel samples were exposed to one meal, or all three in series, a control group was exposed to water and brushed. The daily cycle was repeated to represent two days’ consumption; TTL was quantified by non-contact profilometry. This pilot study highlighted adaptions that could be made to the model such as human enamel and saliva to further replicate natural eating habits. The sum of the TTL measured after Breakfast, lunch and dinner (bovine enamel specimens exposed to single meals) was less than that exhibited by the group of samples exposed to the series of meals but this difference was not significant (p = 0.09).In the absence and presence of brushing, TTL caused by breakfast and dinner was similar, but significantly greater than that caused by lunch (p < 0.05). While brushing increased TTL, this increase was not significant. It is possible to model a daily diet in vitro, and the data obtained confirms that the combination of food and drink affects the degree of TTL. This supports the further development of an in vitro model that includes alternative foodstuffs. This would aid understanding of the effects different diets have on TTL and could test new products designed to prevent TTL.

The wear and tear of teeth

A review is presented of the mechanical damage suffered by tooth crowns. This has been the subject of much recent research, resulting in a need to revise some of the thinking about the mechanisms involved. Damage is classified here by scale into macro-, meso- and microfracture. The focus is on the outer enamel coat because this is the contact tissue and where most fractures start. Enamel properties appear to be tailored to maximize hardness, but also to prevent fracture. The latter is achieved by the deployment of developmental flaws called enamel tufts. Macrofractures usually appear to initiate as extensions of tufts on the undersurface of the enamel adjacent to the enamel-dentine junction and extend from there into the enamel. Cracks that pass from the tooth surface tend to be deflected by an enamel region of high toughness; if they find the surface again, a chip (mesofracture) is produced. The real protection of the enamel-dentine junction here is the layer of decussating inner enamel. Finally, a novel analysis of mechanical wear (microfracture) suggests that the local toughness of the enamel is very important to its ability to resist tissue loss. Enamel and dentine have contrasting behaviours. Seen on a large scale, dentine is isotropic (behaving similarly in all directions) while enamel is anisotropic, but vice versa on a very small scale. These patterns have implications for anyone studying the fracture behaviour of teeth.

SEM-EDX analysis of brushing abrasion of chitosan and propolis based toothpastes on sound and artificial carious primary enamel surfaces

PURPOSE

The objective of this study was to assess the brushing abrasion effects of toothpastes containing chitosan and propolis on sound and demineralized primary tooth enamel.

METHODS

Pairs of enamel specimens were prepared from human extracted primary teeth, embedded in epoxy resin and polished. An artificial subsurface lesion was created in one specimen from each pair. All samples were divided into four groups (Chitodent, Aagaard propolis, Elmex, and Control) and brushed with slurry of toothpastes and artificial saliva in a brushing machine. The brushing abrasion depths were evaluated using computer-guided optical profilometry.

RESULTS

No significant differences existed in terms of brushing depths between artificial carious enamel and brushed sound enamel specimens (P>0.05). The abrasion values of the sound enamel samples brushed with Aagaard propolis and control samples were significantly lower than the Elmex group (P<0.05). The lowest brushing abrasion values of demineralized enamel specimens were observed in the Chitodent group (P>0.05).

CONCLUSIONS

The tested toothpastes exhibited similar effects in terms of brushing abrasion on both sound and artificially demineralized enamel. Based on mean values without statistical significance, the lowest brushing abrasion values in the demineralized brushed enamel samples were detected in the Chitodent group.

Predicting tooth surface loss using genetic algorithms-optimized artificial neural networks

Our aim was to predict tooth surface loss in individuals without the need to conduct clinical examinations. Artificial neural networks (ANNs) were used to construct a mathematical model. Input data consisted of age, smoker status, type of tooth brush, brushing, and consumption of pickled food, fizzy drinks, orange, apple, lemon, and dried seeds. Output data were the sum of tooth surface loss scores for selected teeth. The optimized constructed ANN consisted of 2-layer network with 15 neurons in the first layer and one neuron in the second layer. The data of 46 subjects were used to build the model, while the data of 15 subjects were used to test the model. Accepting an error of ±5 scores for all chosen teeth, the accuracy of the network becomes more than 80%. In conclusion, this study shows that modeling tooth surface loss using ANNs is possible and can be achieved with a high degree of accuracy.

Tooth wear in aging people: an investigation of the prevalence and the influential factors of incisal/occlusal tooth wear in northwest China

Background

The aim of this study was to estimate the prevalence of tooth wear in the aging population of northwest China and to investigate the factors associated with such tooth wear.

Methods

Cross-sectional analytic clinical and questionnaire study was performed in 704 participants who had a mean age of 46.5 ± 0.2 SD and of which 367(52.13%) were males and 337(47.87%) female. These participants were invited when they attended the hospital which located in northwest China for routine oral examination.

Results

In the maxilla of the examined patients, the rate of tooth wear varied from 85.51% for molar group, 89.77% for premolar group, 100.0% for canine group to 87.22% for incisor group. In the mandible, the rates were 86.36%, 88.92%, 100.0% and 91.19% for the four groups respectively. Moreover, both the incisor and canine groups of these patients showed median scores of 3, the premolar group showed a median score of 1, and the molar group had a median score of 2. Additionally, multiple factors were considered to contribute to these patterns of tooth wear, especially the habitual consumption of a hard or sour diet (P < 0.05,odds ratio 1.21, 95% confidence intervals 1.04-1.49).

Conclusions

Tooth wear is a common disease in which the anterior teeth exhibit greater wear than posterior teeth. The data support an association between tooth wear and dietary patterns.

Dental Erosion and Medical Conditions: An Overview of Aetiology, Diagnosis and Management

Tooth wear or tooth surface loss is a normal physiological process and occurs throughout life but is considered pathological when the degree of destruction is excessive or the rate of loss is rapid, causing functional, aesthetic or sensitivity problems. The importance of tooth wear as a dental problem has been increasingly recognized. The findings of a study in Trinidad indicate that the prevalence of tooth wear in a Trinidadian population is comparable to the United Kingdom (UK) and, indeed, that the level of moderate and severe wear is in fact nearly twice as high. The aetiology of tooth wear is attributed to four causes: erosion, attrition, abrasion and abfraction. Erosion is generally considered to be the most prevalent cause of tooth wear in the UK and Europe. Acids that cause dental erosion originate mainly from the diet or the stomach and to a lesser extent, the environment. Underlying medical problems can contribute to the progress of tooth wear due to erosion and the patient may not be aware of these conditions. Moderate to severe tooth wear poses a significant clinical challenge to dental practitioners and may result in treatment that is more complex and costly to the patient both in terms of finances and time spent in the dental chair. This paper provides an overview of aetiology and diagnosis of tooth wear, in particular tooth wear due to erosion, so that medical and dental practitioners may recognize tooth wear early, institute preventive measures and manage patients appropriately.

An Investigation Into the Relationship Between Noncarious Cervical Lesions and Premature Contacts

The aim of the present study was to investigate the relationship between noncarious cervical lesions (NCCL) and dental premature contacts (PC). Following examination of 1,974 teeth from 77 patients referred to the Department of Oral Medicine, Faculty of Dentistry, Mashad University of Medical Science, Iran, a total of 167 teeth were identified to have the criteria set for noncarious cervical lesions (regarded as NCCL group). Also, 167 teeth exhibiting no such lesions were selected randomly from the same population (regarded as control group). The results indicated that within the NCCL group, the frequency of noncarious cervical lesions differed significantly among the various teeth; the first premolar teeth showed the greatest number of cervical lesions, followed by the canine teeth, and the second molar teeth had the least number of lesions. A similar trend was detected in the total number of premature contacts among the seven types of teeth. The results revealed a highly significant and positive correlation between the incidence of NCCL and the PC. The NCCL group and the control group differed significantly in the number of premature contacts in centric relation (CR) and working side, but not in balancing and protrusion.

The management of anterior tooth wear using gold palatal veneers in canine guidance

Localised anterior tooth wear can be managed using minimally invasive techniques with conservation of tooth structure and preservation of pulp vitality. This article describes and illustrates with two clinical cases, the management of localised tooth wear, with the restoration of canine guidance by a combination of gold palatal veneers and direct composite restorations.

A preliminary study to find a possible association between occlusal wear and maximum bite force in humans

OBJECTIVE

The objective of the study was to investigate whether moderate-to-severe attrition is associated with maximum bite force in the first molar region.

METHODOLOGY

Maximum bite force in the first molar region was measured for a total of 60 subjects having moderate-to-severe attrition of occlusal surface (experimental group) using a specially-designed piezoelectric sensor based bite force measuring device. An equal number of age, gender, height and weight matched controls (control group) were also subjected to bite force measurement for comparison.

RESULTS

The maximum bite force was found to be significantly lower (p < 0.05) in the experimental group [480.32 (153.40)] as compared to the controls [640.63 (148.90)]. While analyzing the possible etiology for occlusal wear mainly two reasons were elicited, i.e. history of parafunctional habits like use of known abrasive tooth powder (sub-group A) and Bruxism (sub-group B). However, there were many subjects in which no known definite etiological factors be attributed to occlusal wear (sub-group C). On analysing further with respect to the possibly correlated etiological factors with maximum bite force, no significant difference was found within the experimental sub-group. However, all three experimental sub-groups had significantly lower maximum bite force as compared to age, gender and BMI matched controls.

CONCLUSION

A significantly lower maximum bite force was found to be associated with moderate-to-severe attrition as compared to subjects without attrition. However, no specific relation could be found between bite force and possible etiological factors like history of parafunctional habits, history of use of known abrasive tooth powder, etc.

Tooth surface loss and associated risk factors in northern saudi arabia

Aim. To evaluate tooth surface loss (TSL) severity and associated risk factors in a representative sample of Saudi adults. Materials and Methods. Four hundred TSL patients (200 females and 200 males) participated in this study. Each patient completed a comprehensive questionnaire interview (using a modified Tooth wear Assessment Questionnaire) and then examined for the severity of TSL (using ordinal scale). Results. Seventy-five percent of participants demonstrated attrition, 90% had erosion, 15% had abrasion, and 95% had more than one type of TSL. The most common risk factors were consumption of acidic food/drinks (78%), parafunctional habits (70%), and unilateral chewing (50%). 77% of participants demonstrated grade 2 TSL. Males demonstrated greater TSL severity (P ≤ 0.05). Age, systemic disease, number of remaining teeth, acidic food/drinks, bruxism/parafunction, biting objects, facial pain/tenderness, sour taste, exposure to dust, unilateral chewing, using dental abrasives, and brushing frequency/technique had significant relationship with TSL severity (P ≤ 0.05). Conclusions. TSL has a multifactorial aetiology. Parafunction, gastrointestinal problems, and diet were the most common aetiological factors reflecting changes to stressful modern life-styles, eating/drinking habits, and behaviours. Gender didn't influence the aetiology of TSL; however males demonstrated more TSL severity. Patients' age had significant correlation to TSL severity.

Biologically based restorative management of tooth wear

The prevalence and severity of tooth wear is increasing in industrialised nations. Yet, there is no high-level evidence to support or refute any therapeutic intervention. In the absence of such evidence, many currently prevailing management strategies for tooth wear may be failing in their duty of care to first and foremost improve the oral health of patients with this disease. This paper promotes biologically sound approaches to the management of tooth wear on the basis of current best evidence of the aetiology and clinical features of this disease. The relative risks and benefits of the varying approaches to managing tooth wear are discussed with reference to long-term follow-up studies. Using reference to ethical standards such as “The Daughter Test”, this paper presents case reports of patients with moderate-to-severe levels of tooth wear managed in line with these biologically sound principles.

Tooth wear and wear investigations in dentistry

Tooth wear has been recognised as a major problem in dentistry. Epidemiological studies have reported an increasing prevalence of tooth wear and general dental practitioners see a greater number of patients seeking treatment with worn dentition. Although the dental literature contains numerous publications related to management and rehabilitation of tooth wear of varying aetiologies, our understanding of the aetiology and pathogenesis of tooth wear is still limited. The wear behaviour of dental biomaterials has also been extensively researched to improve our understanding of the underlying mechanisms and for the development of restorative materials with good wear resistance. The complex nature of tooth wear indicates challenges for conducting in vitro and in vivo wear investigations and a clear correlation between in vitro and in vivo data has not been established. The objective was to critically review the peer reviewed English-language literature pertaining to prevalence and aetiology of tooth wear and wear investigations in dentistry identified through a Medline search engine combined with hand-searching of the relevant literature, covering the period between 1960 and 2011.

Evaluation of Microleakage of RMGIC and Flowable Composite Immersed in Soft Drink and Fresh Fruit Juice: An in vitro Study

Aim : The objective of the study was to evaluate and compare the effect of a soft drink and a fresh fruit juice on the microleakage of flowable composite and resin modified glass lonomer cement (RMGIC).

Methods and materials : 70 non-carious human premolars were collected and stored in saline until further use. Class-V cavities were prepared and restored with RMGIC on the buccal surface and flowable composite on the lingual surface for evaluating microleakage. The experimental groups (Group I and II ) comprised of 60 teeth, while the remaining 10 formed the control group (Group III―Water). The experimental groups were further divided into 2 groups (Group I―Cola drink and Group II―Fresh orange fruit juice) of 30 teeth each. Each group was then further divided into 3 subgroups (Short, Medium and Long-immersion) containing 10 teeth as shown in flow chart.

Immersion regime was followed according to Maupome G et al and microleakage was evaluated by using Rhodamine B dye and examined under stereomicroscope.

Results : Microleakage data obtained was statistically analyzed by Chi-square test. The teeth showed statistically significant microleakage as the immersion regime increased.

Interpretation and Conclusion : Low pH soft drink caused highly significant microleakage at the tooth and restorative material interface in medium and high immersion regimes signifying that the leakage pattern was directly proportional to the number of immersions. Thus, the study conclusively proves that the ‘sipping habit’ associated with commonly available low pH beverages is detrimental to the longevity of restorations.

Erosive tooth wear among children in the United States: relationship to race/ethnicity and obesity

OBJECTIVE

The study aims were to estimate the prevalence of erosive tooth wear (ETW) in children and to specifically examine its association with race/ethnicity and obesity in the United States.

DESIGN

We analysed data from the National Health and Nutrition Examination Survey (NHANES), 2003-2004. ETW was measured using the modified Smith and Knight Tooth Wear Index derived from the 1998 United Kingdom Adult Health Survey.

RESULTS

This study shows that 45.9% of children aged 13-19 years had evidence of ETW in at least one tooth. The prevalence of ETW was bilaterally symmetrical in all teeth examined and was most prevalent in mandibular [corrected] teeth. Females had significantly lower rates of ETW of any tooth compared to males. African Americans had significantly lower rates of ETW (except in the canines), and Hispanics had similar rates compared to whites. Compared to 'healthy weight' children, those 'at risk for overweight' had lower rates of ETW and the 'overweight' groups had higher rates, but results were not significant.

CONCLUSIONS

Substantial proportions of children in the US are affected by ETW. Compared to whites, African American children had significantly lower rates of ETW. Although not significant, 'overweight' (obese) children had increased odds of having ETW and those at 'risk for overweight' had lower odds compared to 'healthy weight' children.

The evaluation of direct composite restorations for the worn mandibular anterior dentition ? clinical performance and patient satisfaction

This prospective split-mouth clinical trial evaluated the performance and patient satisfaction of 168 Herculite XRV direct composite restorations bonded to the worn anterior dentition of 18 patients with localized anterior tooth surface loss. One hundred and six of these restorations were placed on the mandibular anterior teeth. The restorations increased the anterior occlusal vertical dimension between 0.5 and 5 mm and the posterior occlusal contacts were restored after a mean duration of 6.2 months (range: 3-13 months) in 14 out of the 15 'Dahl' sub-group patients. The restorations were evaluated after 2.5 years of service by five examiners. Four patients and 23 mandibular restorations were lost to follow-up. Multiple clinical and restorative variables were assessed to determine their influence on restoration performance. Complete failure occurred in 6% of the restorations. Circumferential preparation and height of the restorative addition did not influence the performance of the restorations. A Visual Analogue Scale (VAS) was used to assess the patient's opinion regarding sensitivity, aesthetics, longevity and function of the worn mandibular anterior teeth. A statistically significant difference (95% CI) was found between the pre-operative and 1-month review VAS responses for aesthetics and longevity and this was maintained at the 2.5-year review. Direct composite restorations placed at an increased occlusal vertical dimension are a simple and time-efficient method of managing the worn mandibular anterior dentition. Patient's acceptance and adaptation to the technique is good and the results are accompanied with a high level of patient satisfaction that is maintained for the medium-term.

The outlook for implants and endodontics: a review of the tissue engineering strategies to create replacement teeth for patients

Ideally, root canal therapy involves the removal of diseased pulp tissues and permanent replacement with healthy pulp to revitalize teeth. Rather than placing implants, the ideal solution is to grow new replacement teeth. Success rates of implants and endodontic treatments can exceed 90%, which presents a formidable challenge to tissue engineering researchers to ensure that future dental treatments are even more successful. The purpose of this article is to explain how tissue engineering can be used to create replacement teeth. The science of tissue engineering has evolved from growing simple tissues in cell culture incubators to a multistep process. Although the problems of introducing tissue engineering therapies as part of routine dental treatments are substantial, the potential benefits are equally ground breaking.

Non-carious tooth conditions in children in the UK, 2003

BACKGROUND

The 2003 Children's Dental Health Survey is the fourth of the 10-yearly surveys of children's oral health.

AIM

To report the prevalence of three non-carious tooth conditions in children in the UK.

METHOD

A representative sample of children five, eight, 12 and 15 years of age were examined by calibrated examiners in schools across the UK. The dental examination included accidental damage to incisors, tooth surface loss (TSL) and enamel opacities (age 12 only). A postal questionnaire sought parental and child views on marks on teeth which could not be removed by brushing.

RESULTS

The proportion of children sustaining accidental damage to permanent incisors decreased to 11% of 12 and 13% of 15-year-olds, but the majority of accidental damage remained untreated. TSL was found on 53% of five-year-olds and on approximately a third of 12 and 15-year-olds. There was a statistically significant change for TSL on permanent teeth at age 15 where 27% upper incisors had TSL palatally in 1993 compared to 33% in 2003. Thirty-four per cent of 12-year-old children had enamel opacities on one or more of their teeth compared with 36% in 1993.

CONCLUSIONS

Tooth surface loss remains a common finding in children in the UK. A large proportion of accidental damage to teeth remains untreated.

Tooth wear: diet analysis and advice

Diet analysis and advice for patients with tooth wear is potentially the most logical intervention to arrest attrition, erosion and abrasion. It is saliva that protects the teeth against corrosion by the acids which soften enamel and make it susceptible to wear. Thus the lifestyles and diet of patients at risk need to be analysed for sources of acid and reasons for lost salivary protection. Medical conditions which put patients at risk of tooth wear are principally: asthma, bulimia nervosa, caffeine addiction, diabetes mellitus, exercise dehydration, functional depression, gastroesophageal reflux in alcoholism, hypertension and syndromes with salivary hypofunction. The sources of acid are various, but loss of salivary protection is the common theme. In healthy young Australians, soft drinks are the main source of acid, and exercise dehydration the main reason for loss of salivary protection. In the medically compromised, diet acids and gastroesophageal reflux are the sources, but medications are the main reasons for lost salivary protection. Diet advice for patients with tooth wear must: promote a healthy lifestyle and diet strategy that conserves the teeth by natural means of salivary stimulation; and address the specific needs of the patients' oral and medical conditions. Individualised, patient-empowering erosion WATCH strategies; on Water, Acid, Taste, Calcium and Health, are urgently required to combat the emerging epidemic of tooth wear currently being experienced in westernised societies.

Stem Cell Responses in Tooth Regeneration

Scientific advances in the creation of restorative biomaterials, in vitro cell culture technology, tissue grafting, tissue engineering, molecular biology, and the human genome project provide the basis for the introduction of new technologies into dentistry. This review is intended to facilitate the development of stem cell therapy for use with established therapeutic modalities to restore and regenerate oral tissues. Teeth have been shown to mineralize in response to injury for many decades, but only in recent years has the position of the stem cells been localized around blood vessels. The cells have been identified as myofibroblastoid pericytes. The ability to control the differentiation and proliferation of these cells is being examined to create stem cell therapies that can solve dental problems more effectively than current treatment regimes. Although the problems of introducing these technologies are substantial, the potential benefits to patients and the profession are equally promising - a cure for caries and diseases, a cure for oral cancer, correction of congenital defects, and the regeneration of teeth and tissues to restore oral functions. The purpose of this review is to describe how these new technologies can most usefully be employed in dentistry to enable clinicians to satisfy patient demand for a nondefective dentition.

Effects of occlusal load on cervical lesions

Toothbrush abrasion has been considered to cause cervical lesions. However, some investigators have proposed that occlusal loading factors direct tensile stresses at the cervical area, resulting in wedge-shaped abfraction defects. The purpose of this study is to investigate the role of axial and non-axial load on the development of cervical lesions. Matched paired premolars, extracted for orthodontic purposes, were used in a custom-fabricated toothbrushing apparatus. A periodontal sulcus width of 0b1 mm with 1 mm gingival recession was simulated with denture base resin. In phase 1, eight matched premolar pairs were subjected to 80 h (1b4 million strokes) of brushing and 300 g of toothbrush force. Toothpaste slurry was applied continuously through the toothbrush. One specimen in each pair was subjected to 250 h and 45 kg of continuous axial load, while the other unloaded tooth served as a negative control. In phase 2, 10 matched premolar pairs were subjected to the same conditions; however, the experimental teeth were subjected to 250 h and 45 kg of intermittent non-axial load, directed at a 45 degrees angle to the buccal cusp. Rubber impressions were made of the cervical lesions, then trimmed, weighed, and compared to determine the amount of tooth material lost. When teeth were loaded axially, there was significantly less tooth material loss (P < 0b02); however, when teeth were loaded non-axially, there was no significant difference (P =0b80) when compared with controls. Optical and scanning electron microscopy did not reveal any significant differences in the morphology between pairs. Our data suggest that the application of occlusal load may not necessarily play a significant role in the progression of cervical tooth wear commonly referred to as abfraction.

In vitro microleakage of adhesive-sealed dentin with lactic acid and saliva exposure: a radio-isotope analysis

OBJECTIVES

The aim of this study was to evaluate the dentin-protective potential of two dentin-bonding systems (Syntac and Clearfil SE Bond) on artificial saliva and lactic acid exposure.

METHODS

Radiochemical analysis in combination with polarization-microscopy was used in the current study. Different applications in MOD preparations in irradiated human molars were compared. Untreated cavities and cavities covered with flowable resin served as controls. Forty-eight specimens were immersed in artificial saliva (pH 7.5), 48 in lactic acid (pH 4). Activity of (32)P was measured between days 1 and 21 and loss of mineralized tissue was estimated.

RESULTS

In lactic acid, cavities sealed with single bond, double bond or bond plus cavity sealer application resulted in significantly lower mineralized tissue loss compared to negative controls (p < 0.05). Upon both saliva and lactic acid exposure, bonding plus sealer application proved to be the most protective treatment (p < 0.05).

CONCLUSIONS

Based on these in vitro findings it may be advisable to use a filled cavity sealer or a flowable resin to protect dentin from demineralization. The radiochemical analysis appeared to be valuable in evaluating the protective potential of bonding agents against dentin demineralization.

The survival and clinical performance of resin-based composite restorations used to treat localised anterior tooth wear

OBJECTIVE

To examine the clinical performance of resin-based composite restorations placed at an increased vertical dimension when used to manage localised anterior tooth wear.

DESIGN

A retrospective analysis of cases treated at a single centre.

SETTING

UK Hospital setting in the year 2000.

SUBJECTS AND METHODS

Two hundred and twenty five restorations placed in 31 subjects were included. Assessment was made following examination of study casts and projected slides. Modified United States Public Health Services criteria were used and data analysed using the software Statistical Programme for Social Sciences (SPSS). Survival analysis was carried out at two levels, major failure only and all types of failure. Kaplan-Meier survival plots were produced against different variables and modes of failure were also noted.

RESULTS

Major failure requiring replacement of the restoration was uncommon within the first five years. Minor failure requiring repair or refinishing presented mainly as wear, marginal discolouration or marginal fracture. Median survival was 4 years 9 months when all types of failure were considered. The restorations have good appearance and are well tolerated.

CONCLUSION

Placement of resin-based composite restorations at an increased vertical dimension to treat localised anterior tooth wear, has good short to medium term survival. The technique is conservative and relatively easy to maintain.

Influence of abrasion in clinical manifestation of human dental erosion

The influence of abrasion from oral soft tissues on softened enamel lesion remineralization and erosion development was investigated. Using orange juice, softened enamel lesions were produced on 20 human premolars assigned randomly to 10 volunteers. Sections used as control and two test slabs were cut from each tooth. One of the two slabs from each tooth had an appliance built on it, which protected the lesion from abrasion. The two slabs (with/without appliance) were bonded to the palatal surfaces of upper right and left lateral incisor teeth of the participants who chewed sugar-free gum four times daily. After 28-day intra-oral exposure, mineral loss (Delta Z) and lesion depth (ld) in both control and test samples were quantified using transverse microradiography, and the data was analysed by paired t-test. Delta Z was significantly lower in lesions with appliance (protected), but higher in lesions without appliance (unprotected) when compared with control (unexposed). Similar pattern was observed with lesion depth. In unprotected slabs the lesions were abraded resulting in eroded enamel lesions. It was concluded that erosion observed clinically is the combined effect of demineralization of the tooth surface by an erosive agent and abrasion of the demineralized surface by surrounding oral soft tissues and through food mastication. Abrasion from oral soft tissues can contribute to site-specificity of dental erosion.

Acidic diet and dental erosion among athletes

BACKGROUND

The consumption of acidic foods and drinks is increasing in popularity. The purposes of the present study were to investigate the consumption patterns of acidic foods and drinks among several sport groups and to examine any relationships between consumption patterns and dental erosion.

METHODS

A questionnaire of oral health habits, diet and dental health was developed. Thirty-two sports clubs (690 members) of the University of Melbourne participated in a survey. A total of 508 usable questionnaires were received (74.9 per cent response). Descriptive statistics were prepared and logistic regression was used to explore relationships between dental erosion (dependent variable) and the independent variables.

RESULTS

Dental erosion was reported by 25.4 per cent of respondents, particularly among athletes of the Martial arts (affecting 37.4 per cent). The consumption of acidic foods and drinks was frequent among most athletes. No significant associations were identified between dental erosion and the frequency of drinking soft drinks or sports drinks. Statistically significant associations were found between dental erosion and age group (p=0.004), frequency of drinking juices (p=0.05), and tooth sensitivity (p=0.001).

CONCLUSION

Athletes may be placing themselves unintentionally at risk of dental erosion and dentists could counsel athletes to control and reduce the effect of potentially erosive foods and drinks.

The prevalence, aetiology and clinical appearance of tooth wear: the Nigerian experience

OBJECTIVE

To establish the prevalence and severity of tooth wear among Nigerians and to compare the pattern and aetiology with findings of earlier studies in Western populations.

DESIGN

Clinical examinations for tooth wear using the tooth wear index (TWI).

SETTING

The Federal Republic of Nigeria.

PARTICIPANTS

Patients attending the Dental Hospital, Obafemi Awolowo University Teaching Hospital's Complex Ile-Ife.

OUTCOME MEASURES

Attrition, abrasion and erosion.

RESULTS

Of the 126 patients with tooth wear 81 had attrition, 20 had abrasion, 9 had erosion and 16 had attrition and abrasion combined. A total of 15,480 tooth surfaces were examined. 2,229 (14.4%) surfaces had tooth wear out of which 1,007 (6.5%) were pathologically worn down. The frequency of tooth wear increased with the age of patients. Most of the pathologically worn surfaces were just one point above maximum acceptable value.

CONCLUSIONS

The aetiological factors associated with tooth wear are not different from those encountered in Western cultures but the pattern of wear differs. Pathological tooth wear presents as an age related phenomenon and is probably more severe in Nigerians.

Resistance of an enamel-bonding agent to saliva and acid exposure in vitro assessed by liquid scintillation

OBJECTIVES

To determine the leakage and resistance of a bonding agent and a light-curing fine hybrid composite when exposed to saliva or lactic acid (pH 4) in vitro.

METHODS

Twenty discs in each of four groups of selected irradiated bovine lower central incisors were treated with one of three sealing options: an enamel bond (Heliobond, Vivadent, Schaan, Liechenstein) in a single-step application; Heliobond in a two-step application; and Tetric Flow (Vivadent) as the negative control. One group served as the positive control and remained unsealed. Loss of apatite was determined using the radiochemical method of liquid scintillation. The Cherenkov radiation was assessed in order to evaluate the acid resistance and leakage of smooth surface enamel bonding after exposure to saliva and lactic acid. In addition, replicas were made for SEM analysis of micromorphologic surface changes.

RESULTS

A mean loss of 416.5 g (s.d. 57.0) apatite was observed over the unsealed sites following 14 days of exposure to lactic acid. The application of Heliobond in a one- and two-step application still revealed a remarkable degree of leakage, and substance losses of 196.5 g (s.d. 38.9) and 161.8 g (s.d. 39.7), but a protective potential was evident. In saliva, untreated, as well as sealed teeth, showed a modest leakage that was less than 20 g. When Tetric Flow was used (negative control) leakage was reduced to a minimum of 2.4 g (s.d. 1.0) in saliva and 12.8 g (s.d. 19.6) in lactic acid. These results were confirmed by SEM analysis.

SIGNIFICANCE

The method of liquid scintillation was revealed to be of considerable value in evaluating leakage and acid resistance of potential smooth enamel sealing options. Sealing with an unfilled resin still demonstrated remarkable levels of acid dissolution, although a protection tendency could be observed. This leads to the conclusion that there is a need for further investigation to establish more acid-resistant enamel sealing agents.

Management of tooth surface loss

This part of the series is devoted to tooth surface loss (TSL) not caused by caries or trauma. The management of this form of generalised TSL is included in this series because knowledge of occlusion is needed for both the diagnosis and, when indicated, treatment. There are, however, many other factors involved in the management of generalised TSL other than those associated with 'occlusion'. These will also be discussed.

Dental erosion in a group of British 14-year-old, school children. Part I: Prevalence and influence of differing socioeconomic backgrounds

OBJECTIVES

To establish the prevalence of erosion in a cluster random sample of 14- year-olds in Birmingham UK. To determine whether socioeconomic group influences the prevalence of erosion.

METHODS

The study group consisted of a cluster random sample of 14-year-old school children in Birmingham UK: 418 children were examined from 12 different schools; 209 were male and 209 female. The level of tooth wear was recorded using a modification of the (TWI) index of Smith and Knight (1984). The ACORN classification was used to assess the socioeconomic status of all children.

RESULTS

Results showed that 48% of the children had low erosion, 51% had moderate erosion and only 1% had severe erosion. There were statistically significant differences between males and females; more males had buccal/labial and lingual/palatal tooth surface erosion than females (Chi-square analysis P < 0.001). There was also significantly more erosion observed in teenagers in the lowest socioeconomic categories.

CONCLUSION

It was concluded that moderate levels of dental erosion are common in 14-year-old school children and this may lead to increasing clinical problems. There was significantly more erosion in children from low socioeconomic groups. Possible aetiological factors need to be investigated further.

Resistance of two dentin-bonding agents and a dentin densensitizer to acid erosion in vitro

OBJECTIVES

To determine the resistance of two dentin-bonding agents (DBAs) and a dentin desensitizer to simulated dental erosion.

METHODS

Twenty teeth in each of three groups of selected premolars, with exposed cervical dentin, were treated with one of three dentin surface treatment systems: Gluma Desensitizer (Heraeus Kulzer (UK) Ltd), One Coat Bond (Whaledent (UK) Ltd), and Optibond FL (Kerr (UK) Ltd) and exposed to water (control) and an erosive challenge (Coca Cola) for 14 days. Sequential tracings of the specimens were taken, superimposed and the mean reduction in densensitizer or DBA thickness and or tooth loss determined.

RESULTS

A mean loss of 77 microns (s.d. 14.6 microns) of tooth tissue over the untreated sites following 14 days exposure to Coca Cola was observed. The application of DBAs, as opposed to Gluma Desensistizer alone, over exposed dentin surfaces afforded substantial protection against erosion by Coca Cola over the period of study. The mean change in vertical profile of teeth treated with a DBA was 20 microns (s.d. 14.7 microns), almost four times less than that seen over untreated sites.

SIGNIFICANCE

With the exception of Gluma Desensitizer, which was lost completely, One Coat Bond and Optibond FL demonstrated levels of acid dissolution resistance, which would be of potential value clinically.

Need for occlusal therapy and prosthodontic treatment in the management of temporomandibular disorders. Part II: Tooth loss and prosthodontic treatment

The second part of this review, evaluating the literature on the relationship between dental occlusion and temporomandibular disorders (TMDs), focuses on the aetiological importance of tooth loss and the place of prosthodontic replacement in the treatment of TMD. Loss of teeth and lack of posterior occlusal support seem to have little influence on the development of TMD, which calls into question the use of prosthodontic restoration as prevention or treatment for TMD. In addition, there are practically no studies assessing the benefit of instrumental analysis in diagnosis or comparing the outcome of prosthodontic treatment with simple reversible methods in the management of TMD. There is a trend in the current literature to abandon any treatment, including positioning appliances and prosthodontic measures, to 'recapture the disk' in patients with disk displacements because of the favourable, long-term results achieved after using more simple methods. It is concluded that prosthetic therapy in TMD patients is not appropriate for initial TMD treatment and should only be carried out on prosthodontic indications after reversible treatment has alleviated pain and dysfunction.