Trichomonas tenax and periodontal diseases: a concise review.

Periodontal diseases (gingivitis and periodontitis), result from a disruption of the host-oral microbiome homoeostasis. Whereas the pathological role of some specific bacterial strains during periodontal diseases is well documented, the impact of parasites in periodontium pathophysiology is still under debate. This review aims to collect data about the prevalence and the potential role of Trichomonas tenax during periodontal diseases. Data from 47 studies revealed that T. tenax prevalence in diseased periodontium ranged from 0 to 94·1%. The prevalence of oral protozoan infections was found to be largely greater in patients with periodontal diseases than with healthy periodontium. The parasite detection was mainly performed by direct microscopy. Trichomonas tenax presence was clearly correlated with periodontal disease. The high heterogeneity of its periodontal prevalence may be correlated with the diversity of the population screened (age, sex, systemic diseases), and the methods used for diagnosis. This protozoan seems to have the capacity to be involved in the inflammatory process of gum disease. Animal experimentation, using relevant physiopathological models of periodontitis, needs to be performed to investigate the ability of T. tenax to cause and/or worsen the disease. Further investigations using standardized experimental designs of epidemiologic studies are also needed.

A targeted next-generation sequencing assay for the molecular diagnosis of genetic disorders with orodental involvement.

BACKGROUND: Orodental diseases include several clinically and genetically heterogeneous disorders that can present in isolation or as part of a genetic syndrome. Due to the vast number of genes implicated in these disorders, establishing a molecular diagnosis can be challenging. We aimed to develop a targeted next-generation sequencing (NGS) assay to diagnose mutations and potentially identify novel genes mutated in this group of disorders. METHODS: We designed an NGS gene panel that targets 585 known and candidate genes in orodental disease. We screened a cohort of 101 unrelated patients without a molecular diagnosis referred to the Reference Centre for Oro-Dental Manifestations of Rare Diseases, Strasbourg, France, for a variety of orodental disorders including isolated and syndromic amelogenesis imperfecta (AI), isolated and syndromic selective tooth agenesis (STHAG), isolated and syndromic dentinogenesis imperfecta, isolated dentin dysplasia, otodental dysplasia and primary failure of tooth eruption. RESULTS: We discovered 21 novel pathogenic variants and identified the causative mutation in 39 unrelated patients in known genes (overall diagnostic rate: 39%). Among the largest subcohorts of patients with isolated AI (50 unrelated patients) and isolated STHAG (21 unrelated patients), we had a definitive diagnosis in 14 (27%) and 15 cases (71%), respectively. Surprisingly, COL17A1 mutations accounted for the majority of autosomal-dominant AI cases. CONCLUSIONS: We have developed a novel targeted NGS assay for the efficient molecular diagnosis of a wide variety of orodental diseases. Furthermore, our panel will contribute to better understanding the contribution of these genes to orodental disease. TRIAL REGISTRATION NUMBERS: NCT01746121 and NCT02397824.

A clinical and histological study of dental defects in a 10-year-old girl with pseudoxanthoma elasticum and amelogenesis imperfecta.

BACKGROUND: The prominent dental feature of a 10-year-old girl was severely hypoplastic enamel in permanent teeth. CASE REPORT: Severe dental defects were detected in a 10-year-old female patient affected by pseudoxanthoma elasticum and amelogenesis imperfecta. An orthopantomographic examination revealed a reduction of enamel thickness on the crown of all erupted and unerupted teeth, agenesis of the maxillary right second premolar, delayed eruption of mandibular first premolars, and the presence of large calcifications in all tooth pulp chambers. A detailed histological analysis of permanent mandibular first molars showed that pulp calcifications presented a concentric laminate organization and merged to almost completely obliterate the pulp chamber. Osteodentine was visible all along the pulpal surface of the radicular dentine. Broad resorption areas were present in the outermost dentine at both coronal and radicular levels. Radicular resorption areas presented a typical rectangular form and were filled with acellular cementum. Cementum thickness was highly increased on the root surface. Apposition of cellular cementum-like tissue was also observed on the coronal dentine surface. CONCLUSION: Before treating patients affected by amelogenesis imperfecta and/or pseudoxanthoma elasticum, paediatric dentists should be aware of the presence of pulp calcifications that add to the complexity of endodontic procedures.

Antimicrobial activity of Ca(OH)2 dental cements: an in vitro study.

The effect of five commercial calcium hydroxide root canal medications (XR-SPAD, Calcicur, Hy-cal, Root-cal, Hypo-cal) and two calcium hydroxide mixtures (with water or glycerin) on the growth of (a) three anaerobic bacteria associated with endodontic infections; and (b) saliva bacterial strains was determined using the agar diffusion inhibitory test. Statistically significant zones of bacterial growth inhibition for all the bacteria tested were observed. Calcium hydroxide mixed with glycerin showed the largest zones of bacterial inhibition, whereas Root-cal was the least active. These results underline the necessity to evaluate the antibacterial potential of endodontic medications against the different bacterial strains commonly isolated from infected root canals.

Surface free energy and bacterial retention to saliva-coated dental implant materials--an in vitro study.

The aim of the present investigation was to compare the in vitro bacterial retention on saliva-coated implant materials (pure titanium grade 2 (cp-Ti) and a titanium alloy (Ti-6Al-4V) surfaces), presenting similar surface roughness, and to assess the influence of physico-chemical surface properties of bacterial strain and implant materials on in vitro bacterial adherence. Two bacterial strains (one hydrophilic strain and one hydrophobic strain) were used and the following were evaluated: bacterial cell adherence, SFE values as well as the Lifshitz-van-der Waals, the Lewis acid base components of SFE, the interfacial free energy and the non-dispersive interactions according to two complementary contact angle measurement methods: the sessile drop method and the captive bubble method. Our results showed similar patterns of adherent bacterial cells on saliva-coated cp-Ti and saliva-coated Ti-6Al-4V. These findings could suggest that bacterial colonization (i.e. plaque formation) is similar on saliva-coated cp-Ti and Ti-6Al-4V surfaces and indicate that both materials could be suitable for use as transgingival abutment or healing implant components. The same physico-chemical properties exhibited by saliva-coated cp-Ti and TA6V, as shown by the sessile drop method and the captive bubble method, could explain this similar bacterial colonisation. Therefore, higher values of total surface free energy of saliva-coated cp-Ti and saliva-coated TA6V samples (gamma(SV) approximately 65mJ/m(2)) were reported using the captive bubble method indicating a less hydrophobic character of these surfaces than with the sessile drop method (gamma(S) approximately 44.50mJ/m(2)) and consequently possible differences in oral bacterial retention according the theory described by Absolom et al. The number of adherent hydrophobic S. sanguinis cells was two-fold higher than that of hydrophilic S. constellatus cells. Our results confirm that physico-chemical surface properties of oral bacterial strains play a role in bacterial retention to implant materials in the presence of adsorbed salivary proteins.

[White spot lesions and orthodontic treatment. Prevention and treatment]. / Leucomes et traitement orthodontique. Prévention, traitement.

Decalcification of the enamel surface adjacent to fixed orthodontic appliances, in the form of white spot lesions, is a common and frequent well-known side-effect of orthodontic treatment. Fixed appliances and the bonding materials increase the retention of biofilm and encourage the formation of white spot lesions. Management of these lesions begins with a good oral hygiene regime and needs to be associated with use of fluoride agents (fluoridated toothpaste, fluoride containing mouth rinse, gel, varnish, bonding materials, elastic ligature), CPP-ACP, antiseptics, LASER, tooth whitening, resin infiltration, micro-abrasion. The purpose of this review is to access the direct evidence regarding the prevention and management of white spot lesions during and after orthodontic treatment.

Hand hygiene practices in a dental teaching center: Measures and improve.

OBJECTIVE: To measure the compliance and the quality of HH practices and the knowledge of the healthcare workers' of the university dental care center. MATERIALS AND METHODS: All educators and students present were eligible for inclusion in the study. Each healthcare professional was observed in care situation over a period of 30 min. The knowledge, attitudes and opinions were collected through a questionnaire. RESULTS: Number of healthcare professionals included was 190 (64.4%). Study group consisted of 151 students (74.4%) and 39 educators (42.4%). Out of a total number of expected disinfection of hands (993), 396 were made (39.9%). Educators had a higher compliance rates than students (63.7-35.8%, P = 10(-9)). Large differences were found between care situations (compliance higher before the first care to a patient and lower during installation of patient in dental X-ray area or at exit of dental X-ray area). Concerning hand rubbing (HR), 36.6% were performed correctly, and the main error was all steps of HR not observed (54.4%), and shorter duration (46.7%). The observance and the quality of HR were associated with better knowledge. CONCLUSION: This data suggests areas of improvement: (1) A comprehensive intervention including care organization/clinic ergonomics/planning/anticipation of materials needed for care; (2) the development of HH education program should include the educators, since the behavior of students is strongly influenced and formed by their mentor's attitude and behaviors.