Tooth Root Caries Research Articles

Биомеханическое сравнение керамических, титановых и хромкобальтовых штифтовых вкладок при замещении посттравматических дефектов зуба

The aim of the study is the biomechanical substantiation of restoration of tooth crowns destroyed due to trauma using ceramic post inlays. Materials and research methods. In order to experimentally compare the strength of pin inlays, tooth root and ceramic crown depending on the material of the inlays, three-dimensional mathematical modeling of the stress-strain state of the pin structure using the method of finite element analysis was carried out. The physical and mechanical properties and size of a single-rooted tooth with a fractured crown (upper central incisor), a ceramic crown and a peg inlay made of a chrome-cobalt alloy, titanium or ceramics corresponded to the natural ones. Calculations were performed using the properties of both the devital and the intact tooth. Situations of early operation of the post construction with close contact of the root, inlay, and crown, as well as possible decay of tooth tissues along the edge of the crown in the long-term operation of the construction were simulated. A functional load of 150N was applied to two areas: the incisal edge and the upper third of the palatal surface of the crown on post inlays with a change in load direction from 0 to 90°. Research results and their analysis. According to the data of mathematical modeling of functional load, the strength of a post-traumatic tooth defect replacement is sufficient when using both metal and ceramic post inlays; changes in physical and mechanical properties of the tooth with increasing time from the moment of devitalization increase stress in the ceramic crown, and root failure along the edge of the crown causes the ultimate stress at a horizontal shift of load direction. The biomechanical rationale allows: in case of complete destruction of the crown part of the tooth — to recommend milled dowel ceramic inlays as a support of metal-free artificial crowns; to stick to the technology of their fixation in the root canal and of the fixation of crowns to the inlays; to ensure a strict dispensary of patients with a ceramic crown on milled dowel ceramic inlay to detect and to eliminate tooth root caries in the long term; to provide direction of functional load within 30° from the axis of the restored tooth during prosthetics.

Selection of adhesive systems in treatment of tooth root caries (literature review)

Adhesive dentistry is the foundation on the basis of which there have been global changes in the concept of adhesion of composite materials in therapeutic dentistry, protocols for fixing ceramic restorations in orthopedic dentistry. But a number of unsolved problems remained – the adhesion of composite materials to sclerosed dentin and tooth root cement, the sensitivity of the components of the adhesive systems to the wet environment of the oral cavity and spatial stability in the presence of dentinal fluid moving centrifugally in the dentinal tubules, the lack of restoration of periodontal attachment to the defect that occurs during tooth root caries. The review analyzes the results of studies on the use of self-etching adhesive systems in the treatment of root caries. The physician's ability to choose an adhesive system in a particular clinical case demonstrates his fundamental knowledge and minimizes the percentage of errors that he can make during the treatment phase.

Antibacterial and remineralizing nanocomposite inhibit root caries biofilms and protect root dentin hardness at the margins

ObjectivesSenior patients have a high incidence of tooth root caries. The objectives of this study were to: (1) develop a bioactive composite with calcium (Ca) and phosphate (P) ion-release and antibacterial capabilities via nanoparticles of amorphous calcium phosphate (NACP) and dimethylaminohexadecyl methacrylate (DMAHDM); (2) inhibit root biofilms of Streptococcus mutans, Lactobacillus acidophilus and Candida albicans in a biofilm-based recurrent root caries model to protect root dentin hardness under biofilms for the first time. MethodsFive groups were tested: (1) Heliomolar nanocomposite (Commercial control); (2) Experimental composite control (0% NACP, 0% DMAHDM); (3) Remineralizing composite (30% NACP); (4) Antibacterial composite (3% DMAHDM); (5) Remineralizing and antibacterial composite (NACP + DMAHDM). Colony-forming units (CFU), lactic acid and polysaccharide of biofilms were evaluated. Demineralization of bovine root dentin with restorations was induced via multi-species biofilms, and root dentin hardness was measured. ResultsAdding NACP and DMAHDM into composite did not compromise the mechanical properties (p > 0.05). Biofilm lactic acid, polysaccharides and CFU were greatly reduced via DMAHDM (p < 0.05). Ca and P ion releases were substantially increased at cariogenic low pH. With multi-species biofilm acid attack, root dentin hardness (GPa) decreased to 0.12 ± 0.03 for Commercial control, and 0.11 ± 0.03 for Experimental control. Root dentin hardness was 0.20 ± 0.04 for NACP group, 0.21 ± 0.04 for DMAHDM group, and 0.30 ± 0.03 for NACP + DMAHDM group which was more than 2-fold that of control groups (p < 0.05). ConclusionsThe novel NACP + DMAHDM nanocomposite had strong antibacterial effects and Ca and P ion release. When tested in a multi-species recurrent root caries model, NACP + DMAHDM nanocomposite substantially reduced root dentin demineralization and protected dentin hardness around the restorations under biofilms. Therefore, this novel bioactive composite is promising to inhibit root caries and protect tooth structures.

Prevalence, clinical and morphological features of tooth root caries in the adult human

The incidence of tooth root caries, the morphology of hard dental tissues and the clinical course of the pathology were studied in 4701 (2526 men and 2175 women) residents of St. Petersburg and the Leningrad Region aged 18 to 88 years, which were divided into age groups according to age periodization of Institute of Age Physiology RAS. The highest prevalence of tooth root caries was revealed in the older age groups making 9.88% in elderly age and 7.4% in old age. In young, 1st and 2nd mature age the tooth root caries was diagnosed relatively rare (in 0.26, 1.35 and 5.02% of cases, respectively). Morphological changes in the tooth root cement that predispose to the development of a carious process were determined. In the first adulthood the caries of the tooth root occurred against the background of gum recession in chronic generalized periodontitis especially diabetes patients. In people of the 2nd mature age, elderly and old age the caries of the tooth root was associated with poor oral hygiene, gingival recession due to periodontal disease, as well as in teeth supporting fixed or removable dentures.

Novel bioactive nanocomposite for Class-V restorations to inhibit periodontitis-related pathogens

ObjectivesThe occurrence of tooth root caries is increasing as the world population ages and tooth retention in seniors increases. Class V restorations with subgingival margins are difficult to clean and often lead to periodontitis. The objectives of this study were to develop a Class V composite containing dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP), and investigate mechanical properties and the inhibition of six species of periodontitis-related biofilms for the first time. MethodsEthoxylated bisphenol A dimethacrylate (EBPADMA) and pyromellitic glycerol dimethacrylate (PMGDM) were mixed at 1:1 mass ratio to form the resin matrix. DMAHDM, NACP, and glass particles were incorporated at 3%, 20% and 50% by mass, respectively. Six species were tested: Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Enterococcus faecalis. Colony-forming units (CFU), live/dead assay, biomass via crystal violet staining, and polysaccharide production by biofilms were determined on composites. ResultAdding 3% DMAHDM to composite did not affect the flexure strength and elastic modulus (p>0.1). For all six species of periodontal pathogens, the DMAHDM composite had biofilm CFU nearly three orders of magnitude less than that without DMAHDM. The killing efficacy of DMAHDM composite against the six species was: E. faecalis<F. nucleatum<P. nigrescens=P. intermedia<A. actinomycetemcomitans<P. gingivalis. Biofilm biomass and polysaccharide were also greatly reduced via DMAHDM (p<0.05). SignificanceThe novel nanocomposite containing DMAHDM and NACP showed strong inhibiting effect against all six species of periodontitis-related pathogens. This composite is promising for Class V restorations to restore root caries and combat periodontitis.

Development of a multifunctional adhesive system for prevention of root caries and secondary caries

ObjectivesThe objectives of this study were to: (1) develop a novel adhesive for prevention of tooth root caries and secondary caries by possessing a combination of protein-repellent, antibacterial, and remineralization capabilities for the first time; and (2) investigate the effects of 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM), and nanoparticles of amorphous calcium phosphate (NACP) on dentin bond strength, protein-repellent properties, and dental plaque microcosm biofilm response. MethodsMPC, DMAHDM and NACP were added into Scotchbond Multi-Purpose primer and adhesive. Dentin shear bond strengths were measured. Adhesive coating thickness, surface texture and dentin–adhesive interfacial structure were examined. Protein adsorption onto adhesive resin surface was determined by the micro bicinchoninic acid method. A human saliva microcosm biofilm model was used to investigate biofilm metabolic activity, colony-forming unit (CFU) counts, and lactic acid production. ResultsThe resin with 7.5% MPC+5% DMAHDM+30% NACP did not adversely affect dentin shear bond strength (p>0.1). The resin with 7.5% MPC+5% DMAHDM+30% NACP produced a coating on root dentin with a thickness of approximately 70μm and completely sealed all the dentinal tubules. The resin with 7.5% MPC+5% DMAHDM+30% NACP had 95% reduction in protein adsorption, compared to SBMP control (p<0.05). The resin with 7.5% MPC+5% DMAHDM+30% NACP was strongly antibacterial, with biofilm CFU being four orders of magnitude lower than that of SBMP control.Significance The novel multifunctional adhesive with strong protein-repellent, antibacterial and remineralization properties is promising to coat tooth roots to prevent root caries and secondary caries. The combined use of MPC, DMAHDM and NACP may have wide applicability to bonding agents, cements, sealants and composites to inhibit caries.

Dental Morbid Condition of Hunter-Gatherers on Okinawa Island during the Middle Period of the Prehistoric Shell Midden Culture and of Agriculturalists in Northern Kyushu during the Yayoi Period.

Based on morphological data from bones and teeth, Yayoi people in northern Kyushu are thought to have been immigrants or their descendants. They or their ascendants are thought to have introduced agriculture, especially rice growing to Japan. During the middle period of the prehistoric shell midden culture on Okinawa island, equivalent to the latest Jomon and early Yayoi period, the subsistence of Okinawa islander is thought to have been hunting and gathering. In the present study, the dental morbid condition of the hunter-gatherers and the agriculturalists is compared. As reported in previous studies, the carious teeth ratio of the agriculturalists was found to be higher than that of the hunter-gatherers. Moreover, the missing teeth and tooth root caries, those are thought to have been caused by peripheral periodontal disease, abruptly increased in the elder agriculturalists in the samples studied. Therefore, peripheral periodontal disease is thought to have spread to agriculturalists in northern Kyushu during the Yayoi period.

Oral hygiene--why neglect the tongue?

AbstractMost dentists fail to instruct their patients to routinely clean the tongue. Debris on the dorsal surface of the tongue is removed by fibrous foods and by brushing and scraping.A reduction in plaque formation and tooth root caries in the elderly may be achieved. A source of halitosis will be removed and the taste acuity heightened. The tongue should no longer be neglected in oral hygiene regimes.