Objectives

The aim of this overview is to consider the problems that may be associated with making a diagnosis of dentin hypersensitivity (DHS) and to provide a basis for clinicians to effectively diagnose and manage this troublesome clinical condition.

Materials and methods

A PUBMED literature research was conducted by the author using the following MESH terms: (‘diagnosis’[Subheading] OR ‘diagnosis’[All Fields] OR ‘diagnosis’[MeSH Terms]) AND (‘therapy’[Subheading] OR ‘therapy’[All Fields] OR ‘treatment’[All Fields] OR ‘therapeutics’[MeSH Terms] OR ‘therapeutics’[All Fields]) AND (‘dentin Sensitivity’[MeSH Terms] OR (‘dentin’[All Fields] AND ‘sensitivity’[All Fields]) OR ‘dentin sensitivity’[All Fields]). Variations to the above MeSH terms using terms such as ‘cervical’, ‘dentine’ and ‘hypersensitivity’ as substitutes were also explored, but these searches failed to add any further information.

Results

The literature search provided only limited data on specific papers relating to the clinical diagnosis of DHS by dental professionals. Evidence from these published studies would therefore indicate that clinicians are not routinely examining their patients for DHS or eliminating other possible causes of dental pain (differential diagnosis) prior to subsequent management and may rely on their patients’ self-reporting of the problem. Furthermore, the findings of the Canadian Consensus Document (2003) would also suggest that clinicians are not confident of successfully treating DHS.

Conclusions

It is apparent from reviewing the published literature on the diagnosis of DHS that there are a number of outstanding issues that need to be resolved, for example, (1) is the condition under- or overestimated by dentists, (2) is the condition adequately diagnosed and successfully managed by dentists in daily practice, (3) is the impact of DHS on the quality of life of sufferers adequately diagnosed and treated and (4) is the condition adequately monitored by clinicians in daily practice. These and other questions arising from the workshop forum should be addressed in well-conducted epidemiological and clinical studies in order for clinicians to be confident in both identifying and diagnosing DHS and subsequent management that will either reduce or eliminate the impact of DHS on their patients’ quality of life.

Clinical relevance

Clinicians should be made aware not only of the importance of identifying patients with DHS but also of the relevance of a correct diagnosis that may exclude any confounding factors from other oro-facial pain conditions prior to the successful management of the condition.

Objectives

The aim of the article was to present an overview of the management strategies of dentin hypersensitivity (DHS) and summarize and discuss the therapeutic options.

Materials and methods

A PubMed literature search was conducted to identify articles dealing with dentin hypersensitivity prophylaxis and treatment. We focussed on meta-analyses of available or controlled clinical trials.

Results

DHS therapy should start with noninvasive individual prophylactic home-care approaches. In-office therapy follows with nerve desensitizing, precipitating, or plugging agents. If the hypersensitivity persists, depending on the hard and soft tissue components at reevaluation, i.e., presence or absence of cervical lesions and the gingival contour, adhesive restorations including sealing or mucogingival surgery may be an option. They allow for the establishment of a physicomechanical barrier. As the placebo effect may play an important role, adequate patient management strategies and positive reinforcement may improve the management of DHS in the future.

Conclusions

Lifelong maintenance under the premise of strict control of the causative factors is crucial in the management of DHS.

Clinical relevance

Clinicians are faced with a broad spectrum of therapeutic options. Therapy should not only focus on pain reduction or better elimination but also on the modification of the exposed cervical dentin area based on the defect type.

Objective

The objectives were to bring light on fluoride to control dentin hypersensitivity (DHS) and prevent root caries.

Materials and methods

Search strategy included papers mainly published in PubMed, Medline from October 2000 to October 2011.

Results

Fluoride toothpaste shows a fair effect on sensitive teeth when combined with dentin fluid-obstructing agents such as different metal ions, potassium, and oxalates. Fluoride in solution, gel, and varnish give an instant and long-term relief of dentin and bleaching hypersensitivity. Combined with laser technology, a limited additional positive effect is achieved. Prevention of root caries is favored by toothpaste with 5,000 ppm F and by fluoride rinsing with 0.025–0.1 % F solutions, as the application of fluoride gel or fluoride varnish three to four times a year. Fluoride measures with tablets, chewing gum, toothpick, and flossing may be questioned because of unfavorable cost effectiveness ratio.

Conclusion

Most fluoride preparations in combination with dentin fluid obstruction agents are beneficial to reduce DHS. Prevention of root caries is favorable with higher fluoride concentrations in, e.g., toothpaste.

Clinical relevance

Fluoride is an effective agent to control DHS and to prevent root caries particularly when used in higher concentrations.

Objectives

Oral Health-Related Quality of Life (OHRQoL) can be considered as the scientific expression of that part of a person’s well-being that is affected by his/her oral health. The aim of this paper was to evaluate how to use the data available in the field of research to make a link between OHRQoL and dentin hypersensitivity (DHS) in the dental office.

Materials and methods

Research papers in the field of OHRQoL and DHS and reviews and research papers about OHRQoL were used for analysis in this short review, with a particular insight on the instruments used to evaluate OHRQoL.

Results

Various psychometric instruments have been used to measure OHRQoL that are more or less patient- or expert-centred. Some are generic, others are adapted to specific conditions/domains or populations. The impact of DHS or exposed cervical dentin (ECD) on OHRQoL has been assessed in very few studies. It is therefore of the upmost importance that the use of the OHRQoL as a quality control tool be established in robust clinical studies.

Conclusions/clinical relevance

Future studies evaluating the impact of the DHS/ECD on OHQoL or evaluating the efficacy of desensitising agents should respect some key points, including study design (randomization, placebo/control group, etc.), validated specific questionnaires and trained calibrated practitioners.

Introduction

Dentin hypersensitivity (DHS) is a problematic clinical entity that may become an increasing clinical problem for dentists to treat as a consequence of patients retaining their teeth throughout life and improved oral hygiene practices.

Objectives

The aim of this review was to develop a decision tree for the management of exposed cervical dentin (ECD) and DHS.

Material and methods

A brief PUBMED literature search was performed on dentin hypersensitivity using “MeSH” terms, “review”, and “management”. In addition, some websites and local guidelines were screened.

Results

From this review, it became clear that all dentate patients should routinely be screened for ECD and DHS. In this respect, underdiagnosis of the condition will be avoided and the preventive management can be initiated early.

Conclusion

A decision tree process and a flowchart for daily practice were designed which should be started up as soon as a patient present with ECD or suffers from DHS. This approach takes into account the possible improved quality of life of the patient and is further based on a hierarchy of treatment options. In this respect, active management of DHS will usually involve a combination of at-home and in-office therapies. Starting with the use of desensitizing toothpastes is strongly recommended.

Objectives

The paper’s aim is to review dentin hypersensitivity (DHS), discussing pain mechanisms and aetiology.

Materials and methods

Literature was reviewed using search engines with MESH terms, DH pain mechanisms and aetiology (including abrasion, erosion and periodontal disease).

Results

The many hypotheses proposed for DHS attest to our lack of knowledge in understanding neurophysiologic mechanisms, the most widely accepted being the hydrodynamic theory. Dentin tubules must be patent from the oral environment to the pulp. Dentin exposure, usually at the cervical margin, is due to a variety of processes involving gingival recession or loss of enamel, predisposing factors being periodontal disease and treatment, limited alveolar bone, thin biotype, erosion and abrasion.

Conclusions

The current pain mechanism of DHS is thought to be the hydrodynamic theory. The initiation and progression of DHS are influenced by characteristics of the teeth and periodontium as well as the oral environment and external influences. Risk factors are numerous often acting synergistically and always influenced by individual susceptibility.

Clinical relevance

Whilst the pain mechanism of DHS is not well understood, clinicians need to be mindful of the aetiology and risk factors in order to manage patients’ pain and expectations and prevent further dentin exposure with subsequent sensitivity.

Objective

In contrast to the well-established caries epidemiology, data on dentin hypersensitivity seem to be scarce and contradictory. This review evaluates the available literature on dentin hypersensitivity and assesses its prevalence, distribution, and potential changes.

Materials and methods

The systematic search was performed to identify and select relevant publications with several key words in electronic databases. In addition, the articles’ bibliographies were consulted.

Results

Prevalence rates range from 3 to 98 %. This vast range can be explained partly by the differences in the selection criteria for the study sample and also the variety in diagnostic approaches or time frames. Women are slightly more affected than men and an age peak of 30–40 years has been reported. Still, the prevalence of erosions with dentin exposure seems to increase in younger adults, often resulting in hypersensitivity. In older patients, root surfaces are frequently exposed due to periodontal disease which is associated with a high rate of dentin hypersensitivity, especially after periodontal treatment and intensified brushing activity. On the other hand, the number of affected seniors with tooth loss or even edentulism is reduced. About 25–30 % of the adult population report dentin hypersensitivity. Most dentists also consider it to be a relevant problem in their practice, but they request more information on this topic. Maxillary teeth are affected to a higher extent, but the different teeth show very similar rates. Buccal surfaces clearly show the highest prevalence rates.

Conclusion

In spite of the advances regarding management of dentin hypersensitivity, it still remains an epidemiologically understudied field.

Clinical relevance

Although great variations have been observed in the prevalence of dentin hypersensitivity, this issue is often observed by dentists and related by patients. However, further studies are necessary to find the cause of this condition and refine its management.

Objectives

Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of several different external stimuli, it is often inadequately understood. The purpose of this paper is to discuss different available diagnostic approaches and assessment methods used in order to suggest a basis to diagnose, monitor, and measure these challenging painful conditions related to dentin hypersensitivity in daily practice and scientific projects properly.

Material and methods

A PubMed literature search strategy including the following MeSH terms were used as follows: “dentin sensitivity”[MeSH Terms] OR “dentin”[All Fields] AND “sensitivity”[All Fields] OR “dentin sensitivity”[All Fields] OR “dentin”[All Fields] AND “hypersensitivity”[All Fields] OR “dentin hypersensitivity”[All Fields] AND “diagnosis”[Subheading] OR “diagnosis”[All Fields] OR “diagnosis”[MeSH Terms] AND “assessment”[All Fields] AND (“methods”[Subheading] OR “methods”[All Fields] OR “methods”[MeSH Terms]. Furthermore, alternative terms such as “validity,” “reliability,” “root,” “cervical,” “diagnostic criteria,” and “hypersensitivities” were additionally evaluated.

Results

The literature search, also including the alternative terms and journals, revealed only a small number of specific papers related to valid diagnosis, diagnostic criteria, and assessment methods of dentin hypersensitivity. Outcomes from these publications showed that the response to different stimuli varies substantially from one person to another and is, due to individual factors, often difficult to assess correctly. Furthermore, the cause of the reported pain can vary, and the patient’s description of the history, symptoms, and discomfort might be different from one to another, not allowing a reliable and valid diagnosis.

Conclusions

The dental practitioner, using a variety of diagnostic and measurement techniques each day, will often have difficulties in differentiating dentin hypersensitivity from other painful conditions and in evaluating the success of a conducted therapy in a reliable way.

Clinical relevance

Correct diagnosis of dentin hypersensitivity including a patient’s history screening and a brief clinical examination in combination with the identification of etiologic and predisposing factors, particularly dietary and oral hygiene habits associated with erosion and abrasion, is essential. The relevant differential diagnosis should be considered to exclude all other dental conditions with similar pain symptoms.

Objectives

Oral health-related quality of life is a relatively new but rapidly growing concept in dentistry. It is an aspect of dental health addressing the patient’s perception of whether his/her current oral health status has an impact upon his/her actual quality of life. Dentine hypersensitivity (DHS), which is a common condition of transient tooth pain associated with a variety of exogenous stimuli, may disturb the patient during eating, drinking, toothbrushing and sometimes even breathing. The resulting restrictions on everyday activities can have an important effect on the patient’s quality of life. The aims of this paper were to consider the concept of oral health-related quality of life and to review and discuss the literature on oral health-related quality of life and DHS.

Material and methods

A PubMed literature research was conducted using the terms (“dentin sensitivity” [MeSH Terms] OR (“dentin” [All Fields] AND “sensitivity” [All Fields]) OR “dentin sensitivity” [All Fields]) AND ((“oral health” [MeSH Terms] OR (“oral” [All Fields] AND “health” [All Fields]) OR “oral health” [All Fields]) AND related [All Fields] AND (“quality of life” [MeSH Terms] OR (“quality” [All Fields] AND “life” [All Fields]) OR “quality of life” [All Fields])). Furthermore, a manual search was carried out. Any relevant work published presenting pertinent information about the described issue was considered for inclusion in the review.

Results

The combination of the search terms resulted in a list of only three titles. The few published studies convincingly demonstrated that oral health-related quality of life is negatively affected in patients suffering from DHS.

Conclusions

Patients with sensitive teeth report substantial oral health-related quality of life (OHRQoL) impairment. Nevertheless, knowledge about the influence of DHS on oral health-related quality of life is incomplete and, therefore, needs further research.

Clinical relevance

Oral diseases can lead to physical, psychological and social disability. This paper shows that DHS can have a negative impact on the patients’ OHRQoL.

Background

The atraumatic restorative treatment (ART) approach was born 25 years ago in Tanzania. It has evolved into an essential caries management concept for improving quality and access to oral care globally.

Results

Meta-analyses and systematic reviews have indicated that the high effectiveness of ART sealants using high-viscosity glass ionomers in carious lesion development prevention is not different from that of resin fissure sealants. ART using high-viscosity glass ionomer can safely be used to restore single-surface cavities both in primary and in permanent posterior teeth, but its quality in restoring multiple surfaces in primary posterior teeth cavities needs to be improved. Insufficient information is available regarding the quality of ART restorations in multiple surfaces in permanent anterior and posterior teeth. There appears to be no difference in the survival of single-surface high-viscosity glass-ionomer ART restorations and amalgam restorations.

Discussion

The use of ART results in smaller cavities and in high acceptance of preventive and restorative care by children. Because local anaesthesia is seldom needed and only hand instruments are used, ART is considered to be a promising approach for treating children suffering from early childhood caries. ART has been implemented in the public oral health services of a number of countries, and clearly, proper implementation requires the availability of sufficient stocks of good high-viscosity glass ionomers and sets of ART instruments right from the start. Textbooks including chapters on ART are available, and the concept is being included in graduate courses at dental schools in a number of countries. Recent development and testing of e-learning modules for distance learning has increasingly facilitated the distribution of ART information amongst professionals, thus enabling more people to benefit from ART. However, this development and further research require adequate funding, which is not always easily obtainable. The next major challenge is the continuation of care to the frail elderly, in which ART may play a part.

Conclusion

ART, as part of the Basic Package of Oral Care, is an important cornerstone for the development of global oral health and alleviating inequality in oral care.

Objectives

This study aimed to assess possible dental side effects associated with long-term use of an adjustable oral appliance compared with continuous positive airway pressure (CPAP) in patients with the obstructive sleep apnea syndrome and to study the relationship between these possible side effects and the degree of mandibular protrusion associated with oral appliance therapy.

Materials and methods

As part of a previously conducted RCT, 51 patients were randomized to oral appliance therapy and 52 patients to CPAP therapy. At baseline and after a 2-year follow-up, dental plaster study models in full occlusion were obtained which were thereupon analyzed with respect to relevant variables.

Results

Long-term use of an oral appliance resulted in small but significant dental changes compared with CPAP. In the oral appliance group, overbite and overjet decreased 1.2 (±1.1) mm and 1.5 (±1.5) mm, respectively. Furthermore, we found a significantly larger anterior–posterior change in the occlusion (−1.3 ± 1.5 mm) in the oral appliance group compared to the CPAP group (−0.1 ± 0.6 mm). Moreover, both groups showed a significant decrease in number of occlusal contact points in the (pre)molar region. Linear regression analysis revealed that the decrease in overbite was associated with the mean mandibular protrusion during follow-up [regression coefficient (β) = −0.02, 95 % confidence interval (−0.04 to −0.00)].

Conclusions

Oral appliance therapy should be considered as a lifelong treatment, and there is a risk of dental side effects to occur.

Clinical relevance

Patients treated with the oral appliance need a thorough follow-up by a dentist or dental-specialist experienced in the field of dental sleep medicine.

Objectives

Enamel matrix derivative (EMD) has proven to enhance periodontal regeneration; however, its effect is mainly restricted to the soft periodontal tissues. Therefore, to stimulate not only the soft tissues, but also the hard tissues, in this study EMD is combined with an injectable calcium phosphate cement (CaP; bone graft material). The aim was to evaluate histologically the healing of a macroporous CaP in combination with EMD.

Materials and methods

Intrabony, three-wall periodontal defects (2 × 2 × 1.7 mm) were created mesial of the first upper molar in 15 rats (30 defects). Defects were randomly treated according to one of the three following strategies: EMD, calcium phosphate cement and EMD, or left empty. The animals were killed after 12 weeks, and retrieved samples were processed for histology and histomorphometry.

Results

Empty defects showed a reparative type of healing without periodontal ligament or bone regeneration. As measured with on a histological grading scale for periodontal regeneration, the experimental groups (EMD and CaP/EMD) scored equally, both threefold higher compared with empty defects. However, most bone formation was measured in the CaP/EMD group; addition of CAP to EMD significantly enhanced bone formation with 50 % compared with EMD alone.

Conclusions

Within the limits of this animal study, the adjunctive use of EMD in combination with an injectable cement, although it did not affect epithelial downgrowth, appeared to be a promising treatment modality for regeneration of bone and ligament tissues in the periodontium.

Clinical relevance

The adjunctive use of EMD in combination with an injectable cement appears to be a promising treatment modality for regeneration of the bone and ligament tissues in the periodontium.

Objectives

The purpose of this study was to analyze the prevalence of dental erosion among competitive swimmers of the local swimming club in Szczecin, Poland, who train in closely monitored gas-chlorinated swimming pool water.

Materials and methods

The population for this survey consisted of a group of junior competitive swimmers who had been training for an average of 7 years, a group of senior competitive swimmers who had been training for an average of 10 years, and a group of recreational swimmers. All subjects underwent a clinical dental examination and responded to a questionnaire regarding aspects of dental erosion. In pool water samples, the concentration of calcium, magnesium, phosphate, sodium, and potassium ions and pH were determined. The degree of hydroxyapatite saturation was also calculated.

Results

Dental erosion was found in more than 26 % of the competitive swimmers and 10 % of the recreational swimmers. The lesions in competitive swimmers were on both the labial and palatal surfaces of the anterior teeth, whereas erosions in recreational swimmers developed exclusively on the palatal surfaces. Although the pH of the pool water was neutral, it was undersaturated with respect to hydroxyapatite.

Conclusion

The factors that increase the risk of dental erosion include the duration of swimming and the amount of training. An increased risk of erosion may be related to undersaturation of pool water with hydroxyapatite components.

Clinical relevance

To decrease the risk of erosion in competitive swimmers, the degree of dental hydroxyapatite saturation should be a controlled parameter in pool water.

Objectives

A multicentric randomized, 3-year prospective study was conducted to determine for how long Biodentine, a new biocompatible dentine substitute, can remain as a posterior restoration.

Materials and methods

First, Biodentine was compared to the composite Z100®, to evaluate whether and for how long it could be used as a posterior restoration according to selected United States Public Health Service (USPHS)’ criteria (mean ± SD). Second, when abrasion occurred, Biodentine was evaluated as a dentine substitute combined with Z100®.

Results

A total of 397 cases were included. This interim analysis was conducted on 212 cases that were seen for the 1-year recall. On the day of restoration placement, both materials obtained good scores for material handling, anatomic form (0.12 ± 0.33), marginal adaptation (0.01 ± 0.10) and interproximal contact (0.11 ± 0.39). During the follow-up, both materials scored well in surface roughness (≤1) without secondary decay and post-operative pain. Biodentine kept acceptable surface properties regarding anatomic form score (≤1), marginal adaptation score (≤2) and interproximal contact score (≤1) for up to 6 months after placement. Resistance to marginal discoloration was superior with Biodentine compared to Z100®. When Biodentine was retained as a dentine substitute after pulp vitality control, it was covered systematically with the composite Z100®. This procedure yielded restorations that were clinically sound and symptom free.

Conclusions

Biodentine is able to restore posterior teeth for up to 6 months. When subsequently covered with Z100®, it is a convenient, efficient and well tolerated dentine substitute.

Clinical relevance

Biodentine as a dentine substitute can be used under a composite for posterior restorations.

Aim

The technical quality of a root canal treatment is clinically judged by the apical extension and homogeneity of the filling material imaged by periapical radiographs (PA). The aim of this experiment was to evaluate the association between the technical quality of the root canal filling and treatment outcome.

Materials and methods

In 234 teeth (268 roots) that underwent root-canal treatment, the quality of the root canal filling as well as the outcome of the treatment were assessed with both PA and cone-beam computed tomography (CBCT) 2 years after treatment. Satisfactory root filling on PA was defined as 0–2 mm within the radiographic apex without voids; on CBCT scans, the apical end of the canal replaced the radiographic apex. The outcome predictors were analyzed using multivariate logistic regression.

Results

At recall, periapical radiolucent areas were absent in 198 (74%) roots on PA and 164 (61%) roots on CBCT scans. The presence of preoperative periapical radiolucency and the quality of root filling and coronal restoration were identified by both PA and CBCT as outcome predictors (p < 0.01). Complete absence of post-treatment periapical radiolucency was observed in CBCT scans in 81% and 49% of satisfactory and unsatisfactory root fillings, respectively, as compared to 87% and 61% revealed by PA.

Conclusion

Satisfactory root fillings were associated with a favorable outcome, confirmed by both PA and CBCT.

Clinical relevance

The outcome of root canal treatment is improved once the filling is 0–2 mm from the apex, and no voids could be detected. Technical skills and performance of root canal filling procedures should be emphasized, and suitable methods should be developed in order to achieve more compacted filling materials without voids and at the correct length.

Aim

The aim of this study is to examine the survival distributions of primary root canal treatment using interval-censored data and to assess the factors affecting the outcome of primary root canal treatment, in terms of periapical healing and tooth survival.

Materials and methods

About one tenth of primary root canal treatment performed between January 1981 and December 1994 in a dental teaching hospital were systematically sampled for inclusion in this study. Information about the patients' personal particulars, medical history, pre-operative status, treatment details, and previous review status of the treated teeth, were obtained from dental records. Patients were recalled for examination clinically and radiographically. Treatment outcomes were categorized according to the status for periapical healing and tooth survival. The event time was interval-censored and subjected to survival analysis using the Weibull accelerated failure time model.

Results

A total of 889 teeth were suitable for analysis. Survival curves of both outcome measures (periapical healing and tooth survival) declined in a non-linear fashion with time. Median survival of the treated teeth was 119 months (periapical healing) and 252 months (tooth survival). Age, tooth type, pre-operative periapical status, occlusion, type of final restoration, and condition of the tooth/restoration margin were significant factors affecting both periapical healing and tooth survival. Apical extent and homogeneity of root canal fillings had a significant impact towards periapical healing (p < 0.05), but not tooth survival.

Conclusion

The longevity of treated teeth based on tooth survival was considerably greater than that of periapical healing. Both outcome measures were affected by a number of socio-demographic, pre-, intra-, and post-operative factors.

Clinical relevance

Root canal-treated teeth may continue to function for a considerable period of time even though there may be radiographic periapical lesion present. Decision for extraction may be due to reasons other than a failure of the periapical tissues to heal.

Objectives

Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims.

Materials and methods

First, volunteers brushed 2 weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12 h after brushing and bacterial concentrations and viabilities were measured. The contributions of plaque and saliva towards substantivity were determined by combining control plaques with experimental plaque or saliva samples and subsequently assessing their viabilities. Bacterial compositions in the various plaque and saliva samples were compared using denaturing gradient gel electrophoresis.

Results

The viabilities of plaques after brushing with Colgate-Total® and Crest-Pro-Health® were smaller than of control plaques and up to 12 h after brushing with Crest-Pro-Health® plaques still contained effective, residual antibacterial activity against control plaques. No effective, residual antibacterial activity could be measured in saliva samples after brushing. There was no significant difference in bacterial composition of plaque or saliva after brushing with the different toothpastes.

Conclusions

Plaque-left-behind after mechanical cleaning contributes to the substantive action of an antibacterial toothpaste containing stannous fluoride (Crest-Pro-Health®).

Clinical relevance

The absorptive capacity of plaque-left-behind after brushing is of utmost clinical importance, since plaque is predominantly left behind in places where its removal and effective killing matter most. Therewith this study demonstrates a clear and new beneficial effect of the use of antibacterial toothpastes.

Objectives

This study aims to evaluate the influence of different surface preparation techniques on long-term bonding effectiveness to eroded dentin.

Materials and methods

Dentin specimens were eroded by pH cycling or were left untreated as control, respectively. Five different “preparation” techniques were applied: (1) cleaning with pumice, (2) air abrasion, (3) silicon polisher, (4) proxo-shape, and (5) diamond bur. The three-step etch-and-rinse adhesive OptiBond FL (O-FL; Kerr) and the mild two-step self-etch adhesive Clearfil SE Bond (C-SE; Kuraray) were evaluated. Micro-tensile bond strength was measured after water storage for 24 h and 1 year. Fracture analysis was performed by stereomicroscopy and SEM. Interfaces were characterized by TEM. Differences were statistically analyzed with a linear mixed effects model (α = 0.05).

Results

Erosion reduced bond strength in all groups, but this effect was less prominent when eroded dentin was prepared by diamond bur. Storage lowered bond strength in almost all groups significantly, but this ageing effect was more prominent for the eroded surfaces than for non-eroded controls. Whereas after 1-year control specimens revealed superior bond strength with the three-step etch-and-rinse adhesive (O-FL), the mild two-step self-etch adhesive (C-SE) revealed a better 1-year bond strength to eroded dentin. The interface at eroded dentin appeared very prone to degradation as was shown by the increased amount of adhesive failures and by the silver infiltration detected by TEM.

Conclusions and clinical relevance

Although a minimally invasive approach should clinically always be strived for, superficial preparation (or minimal roughening) with a diamond bur is recommendable for long-term bonding to eroded dentin.

Objectives

Toothbrushing, though aimed at biofilm removal, also affects the lubricative function of adsorbed salivary conditioning films (SCFs). Different modes of brushing (manual, powered, rotary–oscillatory or sonically driven) influence the SCF in different ways. Our objectives were to compare boundary lubrication of SCFs after different modes of brushing and to explain their lubrication on the basis of their roughness, dehydrated layer thickness, and degree of glycosylation. A pilot study was performed to relate in vitro lubrication with mouthfeel in human volunteers.

Materials and methods

Coefficient of friction (COF) on 16-h-old SCFs after manual, rotary–oscillatory, and sonically driven brushing was measured using colloidal probe atomic force microscopy (AFM). AFM was also used to assess the roughness of SCFs prior to and after brushing. Dehydrated layer thicknesses and glycosylation of the SCFs were determined using X-ray photoelectron spectroscopy. Mouthfeel after manual and both modes of powered brushing were evaluated employing a split-mouth design.

Results

Compared with unbrushed and manually or sonically driven brushed SCFs, powered rotary–oscillatory brushing leads to deglycosylation of the SCF, loss of thickness, and a rougher film. Concurrently, the COF of a powered rotary–oscillatory brushed SCF increased. Volunteers reported a slightly preferred mouthfeel after sonic brushing as compared to powered rotating–oscillating brushing.

Conclusion

Deglycosylation and roughness increase the COF on SCFs.

Clinical relevance

Powered rotary–oscillatory brushing can deglycosylate a SCF, leading to a rougher film surface as compared with manual and sonic brushing, decreasing the lubricative function of the SCF. This is consistent with clinical mouthfeel evaluation after different modes of brushing.