Epstein-Barr Virus-Infected Plasma Cells Infiltrate Erosive Oral Lichen Planus.

Epstein-Barr virus (EBV), in addition to its transforming properties, contributes to the pathogenesis of several inflammatory diseases. Here, we investigated its involvement in oral lichen planus (OLP), a common autoimmune-like disease of unknown etiopathogenesis that can display a malignant potential. EBV-infected cells (EBV+ cells) were sought in a large series of clinically representative OLPs ( n = 99) through in situ hybridization to detect small noncoding EBV-encoded RNAs. Overall, our results demonstrated that EBV was commonly found in OLP (74%), with significantly higher frequency (83%) in the erosive form than in the reticular/keratinized type mild form (58%). Strikingly, many erosive OLPs were massively infiltrated by large numbers of EBV+ cells, which could represent a large part of the inflammatory infiltrate. Moreover, the number of EBV+ cells in each OLP section significantly correlated with local inflammatory parameters (OLP activity, infiltrate depth, infiltrate density), suggesting a direct relationship between EBV infection and inflammatory status. Finally, we characterized the nature of the infiltrated EBV+ cells by performing detailed immunohistochemistry profiles ( n = 21). Surprisingly, nearly all EBV+ cells detected in OLP lesions were CD138+ plasma cells (PCs) and more rarely CD20+ B cells. The presence of EBV+ PCs in erosive OLP was associated with profound changes in cytokine expression profile; notably, the expression of key inflammatory factors, such as IL1-ß and IL8, were specifically increased in OLP heavily infiltrated with EBV+ PCs. Moreover, electron microscopy-based experiments showed that EBV+ PCs actively produced EBV viral particles, suggesting possible amplification of EBV infection within the lesion. Our study thus brings conclusive evidence showing that OLP is commonly infiltrated with EBV+ PCs, adding a further puzzling element to OLP pathogenesis, given that PCs are now considered to be major regulatory immune cells involved in several autoimmune diseases (ClinicalTrials.gov NCT02276573).

Clinical decision on pit and fissure sealing according to the occlusal morphology. A descriptive study.

BACKGROUND: The objective of this descriptive study was to evaluate the clinical decision on sealing pits and fissures according to the occlusal morphology in patients with low individual caries risk (ICR). MATERIALS AND METHODS: A total of 222 dentists, 86 affiliated to the French Society of Paediatric Odontology (SFOP) and 136 general practice dentists (GPs), answered the same questionnaire with illustrations of 4 occlusal surfaces of permanent molars: they indicated firstly if these were at risk and secondly the corresponding decision regarding sealing. This questionnaire assessed the decision on widening pits and fissures before sealing and the type of sealant material used. Multivariate logistic regression analyses were performed to identify the factors associated with the clinical decision to widen pits and fissures. RESULTS: Sealing of at-risk teeth was indicated by 89% of dentists, whereas sealing of not at-risk occlusal surfaces was recommended by 46%. SFOP dentists were more prone to recommend pit and fissures sealants. The multivariate analyses demonstrated that only the type of material was associated with the clinical decision to widen pits and fissures. Forty eight percent of dentists choose the same material in all clinical situations. CONCLUSION: The wide variations in sealant use and placement technique implies there is no apparent consensus among GP and SFOP dentists. Although the criteria are similar in numerous scientific societies, not all dentists are acting upon these recommendations.

Manual toothbrush wear and consequences on plaque removal.

OBJECTIVE: The aim of this study was to determine the mean time interval before needing to discard different types of manual toothbrushes based on wear, and on the impact of progressive wear on plaque removal efficacy. METHODOLOGY: Two cross-over randomized clinical trials involving the same 12 volunteers tested four toothbrushes of different designs. In Study 1, the brushes were the Butler 211 (BTB) and Fluocaril Sensia (FSTB). In Study 2, the brushes were Elmex InterX (ETB) and Elgydium Interactive (ELTB). In both trials, the volunteers randomly used one of the two toothbrushes for two minutes twice a day during the first week, and the other brush during the following week, and continued this alternating routine for two months. An image acquisition system and the Visilog 5.2 image analysis program were used to calculate the wear index (WI) after one and two months of use for each toothbrush. The OHI-S plaque index (PI) was recorded after one and three minutes of tooth brushing at one and two months. The Friedman or Kruskal-Wallis test was used to compare data. RESULTS: Except for the ELTB, the wear of the toothbrushes was greater during the first month of brushing than during the second. The total WI was FSTB 35.46 (range = 62.11), ELTB 30.14 (range = 67.92), ETB 48.77 (range = 123.87), and BTB 98.20 (range = 134.75). The differences were significant at p = 0.008. The post one-minute PI scores significantly increased with wear, except in the case of ELTB (p = 0.244). When comparing all toothbrushes' PI at the one and three-minute tooth brushing times, there were significant differences at one month among them at p < 0.0001. CONCLUSION: The amount of wear depended on the toothbrush design. It was greater for rectangular tooth brushing areas or when bristles had smaller diameters and different heights. With two-month-old toothbrushes, plaque removal was better when there was less measurable wear.

Reduced salivary flow induced by systemic isotretinoin may lead to dental decay. A prospective clinical study.

BACKGROUND: The adverse effects of isotretinoin have been well documented, but dental side effects over the course of treatment have never been studied. OBJECTIVES: To prospectively document the oral side effects experienced by a group of patients taking isotretinoin and to compare the changes in oral health and salivary parameters with a control group. METHODS: A cohort study was conducted within the dermatology department at the University Hospital in collaboration with two private dermatology practices in Nice, France. Patients were treated at a dose of 0.5 mg/kg/day. The control group was made up of students from the University of Nice-Sophia-Antipolis. The salivary flow, the buffer capacity of saliva, the number of pathogen bacteria and the DMFT index (number of decayed, missing and filled teeth) were assessed at each visit. RESULTS: Eighteen patients and 99 controls were available for evaluation. None of the oral parameters varied with time in the control group, whereas the DMFT significantly increased in the treated group (3.07 +/- 3.85 vs. 3.41 +/- 4.36; p<0.036). The salivary flow gradually decreased with time (p<0.004), but the patients recovered their baseline salivary flow 2 months after the end of the treatment. CONCLUSIONS: This study clearly showed that patients treated with isotretinoin experienced oral side effects.

Root canal posts for the restoration of root filled teeth.

BACKGROUND: The foundation for the reconstruction of endodontically-treated teeth can be provided by a metal or a non-metal post and core system but no guidelines exist for choosing one or the other in particular clinical cases. OBJECTIVES: To assess the effectiveness of different post and core systems for the restoration of endodontically-treated teeth. The primary objective of this review was to compare the clinical failure rates of the different types of posts. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2005, Issue 3), MEDLINE (from 1966 to September 2005), Scopus (from January 1985 to December 2004) and EMBASE (until December 2004). We looked through reference lists of articles and dental conference proceedings. We contacted researchers in the field and manufacturers. SELECTION CRITERIA: Randomised or quasi-randomised clinical trials (RCTs) comparing failures on endodontically-treated permanent teeth with different types of post. The outcomes were loss of retention, post fracture and root fracture. DATA COLLECTION AND ANALYSIS: Two review authors (Michele Muller-Bolla (MMB) and Cybele Borg (CB)) independently assessed the quality of trials and extracted data. Study authors were contacted for additional information. MAIN RESULTS: Two trials involving 317 participants were included but only one of them, involving 200 participants, compared metal to non-metal posts. The other answered to the secondary objective. The risk of failure was greater with metal-cast posts (9/98) compared to carbon fibre posts (0/97) (risk ratio (RR) = 0.05 (95% confidence interval (CI) 0.00 to 0.90)) but the study was at high risk of bias. Thus fewer failures occurred when using non-metal posts but the evidence is unreliable. AUTHORS' CONCLUSIONS: Our systematic review could not specify which type of post and core system should be used when two or three dentine walls remain. More RCTs are needed to confirm whether fibre-reinforced post and core systems are superior and to clarify the influence of the remaining tooth structure on the treatment outcome of the different post and core systems available. Well-defined inclusion criteria focusing on the number of dentine walls (two or three) should be used.

Effect of sono-abrasion in the microleakage of a pit and fissure sealant.

PURPOSE: To assess the microleakage of a pit and fissure sealant after preparing enamel with sono-abrasion, used alone or associated with acid etching. This technique was compared with classical enamel preparations i.e. acid etching and diamond bur associated with etching. MATERIALS AND METHODS: Ninety 3rd molars were used. In the mesial halves, the fissures were prepared with sono-abrasion and acid etching for 15 seconds. Then, the samples were randomly assigned to three groups of 30. They were either treated with acid etching alone (group 1), widened mechanically with a bur and etched for 15 seconds (group 2) or prepared with sono-abrasion alone (group 3). Then, the resin-based sealant was applied according to the manufacturer's recommendations. The teeth were thermocycled and placed in a 1% solution of methylene blue. The teeth showing microleakage and the means of infiltration were assessed with an image analysis system. RESULTS: The poorest results were obtained with sono-abrasion alone which showed a greater number of specimens with microleakage (73.3%) (p < 0.001). They also showed the highest mean of microleakage (0.85+/-0.79 mm vs 0.1+/-0.26 for acid; 0.35+/-0.85 for bur associated with etching p < 0.0001); and 0.19+/-0.45 for sono-abrasion associated with etching. CONCLUSION: No significant difference was noted between the three types of enamel preparation using etching. Sono-abrasion can be used for preparing dental enamel prior to sealing the tooth but it does not eliminate the need for etching.

In vitro action of Bordeaux red wine on the microhardness of human dental enamel.

Several studies have demonstrated that the regular and large consumption of wine is associated with increased risk of tooth erosion. Here, the effect of Bordeaux red wine on enamel was estimated by measuring changes in its Vickers microhardness. Thirty premolars were used; microhardness tests were performed on buccal areas before and after 10, 30, 90 and 120 s immersion in the wine (pH=3.9). Enamel surfaces were also observed by scanning electron microscopy. No statistically significant difference was found between the mean Vickers microhardness obtained at t=0 and 90 s, but slight signs of enamel demineralisation were observed with the scanning electron microscope. It appears that wine has no disastrous effect on the microhardness of dental enamel when the two are in contact for less than 90 s. When the exposure is for at least 120 s, it may become harmful, as the decrease in the microhardness of enamel was then significant (P<0.05).

Periapical status, prevalence and quality of endodontic treatment in an adult French population.

AIM: The aim of this study was to determine the periapical status and the quality of root-canal treatment amongst an adult population attending the dental school in Nice, France during 1998. METHODOLOGY: Patients who attended the dental school for the first time during 1998 were included. Panoramic radiographs, taken by a trained radiology assistant, were used in this study. The periapical areas of all teeth with the exception of third molars, were examined and the technical quality of root fillings were evaluated for both apical extension and density. Statistical analyses were conducted using anova, Chi-square, Fisher's PLSD and Cohen's Kappa tests. RESULTS: The survey involved 344 patients: 180 females and 164 males. Males had significantly fewer natural remaining teeth than females (P<0.03). Similarly, the average number of root-filled teeth was lower for males (P<0.01). Nonroot-filled teeth (n=6126) had significantly fewer signs of periapical pathology than root-filled teeth (n=1429) (1.7% vs. 31.5%, P<0.0001). The majority of root fillings were poorly executed. There was a significant correlation between the presence of periapical pathology and inadequate root-canal fillings (P<0.001). CONCLUSIONS: The results of the present study indicate that many root-canal treatments were technically unsatisfactory in terms of quality and treatment outcome. There is a need for endodontic retreatment in the population examined.

Odontometrical method useful in determining gender and dental alignment.

Rao et al.'s method of sex determination, which considers the mandibular canine index (MCI) is one giving satisfactory results. However, they did not take occlusion into consideration. The aim of this study, therefore, was to evaluate the effectiveness of this method with respect to tooth alignment. The study population involved the students enrolled in the University of Nice-Sophia Antipolis. Two hundred and ten girls and 214 boys were randomly sampled (1/20). Both tooth sizes and dental arches were measured using a vernier calliper to calculate MCI for both sexes. The results were compared to standard MCI, taking into account tooth alignment.Rao et al.'s method can only be used in the case of correct lower-anterior dental alignment and by using the standard MCI of the local population.

Restorative materials used on primary teeth: a comparative study between two European universities: Nice and Amsterdam.

A descriptive retrospective survey was carried in two European dental schools (UNSA - Nice and ACTA - Amsterdam), in order to compare the restorative materials used in deciduous dentition. Examination of 460 patient files showed that age and sex distribution among children in both cities was comparable. The dft scores were also comparable but the number of decayed teeth was higher in Nice (4.61 +/- 2.68) than in Amsterdam (2.86 +/- 2.30). In Nice, composite resins, compomers and glass ionomers were all used in deciduous anterior teeth whereas only compomers were used in Amsterdam. As far as deciduous molars were concerned, composite resins and amalgams were used on small and large cavities respectively in Nice whereas in Amsterdam, compomers were once again preferred.

Curved molar root canal preparations using Hero 642 rotary nickel-titanium instruments.

AIM: The Bramante method was used to study how the natural curvature of root canals was modified when using the Hero 642 nickel-titanium rotary system. METHODOLOGY: Twenty-four canals were selected in freshly extracted human mandibular molars. Every root canal had an angle of curvature greater than 20 degrees. Roots were embedded in clear casting resin using a plaster mould. Cross-sectional cuts were made in the apical, middle and coronal thirds of each root. A first group (control) of 12 curved root canals was prepared using stainless steel hand instruments and the step-back technique. A second group of 12 curved root canals was instrumented using the Hero sequence according to the manufacturer's instructions. For each sectioning level, the amount of dentine removed, the change of shape factor and the canal centre displacement were calculated with the aid of a digital image analysis system. The results were subjected to the Mann-Whitney U-test. RESULTS: No significant difference occurred in the amount of dentine removed, change of shape factor or canal centre displacement in the coronal and middle thirds of the curved canals. In the apical third, transportation was significantly higher (P=0.0171) with stainless steel hand instruments than with the Hero system. CONCLUSIONS: The original canal shape was maintained better in the apical third of curved canals when using the Hero system in a crown-down technique when compared to a hand preparation technique with stainless steel instruments.

Effect of surface penetrating sealant on surface texture and microhardness of composite resins.

The application of Fortify (Bisco, Lombard, IL), an unfilled resin, to the surface of composite resin restorations is intended to fill in defects in the surface that persist despite polishing, improve marginal integrity, and increase these materials' resistance to abrasion. The aim of this study was to observe the surface texture by scanning electron microscopy and measure the microhardness of the surface. For each sample of composite resin covered with glaze, 40 measurements were made of the thickness of the resin. Measurements of the Vickers microhardness included three samples of composite resin, three samples of glaze, and six samples of composite resin covered with glaze. A relationship was established between microhardness and thickness. Scanning electron microscopy showed a noticeable improvement in the surface texture. Nevertheless, areas were seen in which glaze seemed very thin or even completely absent. Measurements of the thickness ranged from 0-70 microm. The mean microhardness of composite resin was 65.8 +/- 0.7, while the mean hardness of glaze was 7.3 +/- 0.7. The microhardness of the double layer was reduced, depending on the thickness of the glazing resin. The capacity of glaze to mask surface defects of composite resin was shown, but it was difficult to obtain a regular surface with liquid resin. The application of this product caused a decrease of the microhardness of the composite resin's surface.