The effect of impaired dentin formation on dental caries:an experimental study in the molars of growing rats

Abstract The effects of dietary sucrose and systemic glucocorticoid treatment on the response of the pulpodentinal complex to dental caries were examined in an experimental rat model. The possible role of dentinal caries on dentin formation was also examined. After 5-6 weeks of a dietary and/or medication period, the areas of dentin formation and dentinal caries were quantified in the molars of growing animals. Also the number and severity of caries lesions were estimated. The 43% sucrose diet significantly reduced dentin formation and increased dentinal caries progression. Although glucocorticoid medication alone reduced dentin formation, without dietary sucrose it did not have an effect on caries. In combination of these two, glucocorticoids further increased the progression of dentinal caries, however without significant increase in the number of caries lesions. The cariogenic bacterial inoculation of rats fed a sucrose or control diet increased the progression of dentinal caries. The relationship between cariogenic bacteria and caries was not strong, but there was a stronger relationship between the total amount of dietary sucrose and dentinal caries. In addition to the overall reduction of dentin formation there was no difference in the amount of dentin formed between intact and carious fissures in the sucrose diet group. On the contrary, rats receiving the control diet positively responded to the dentinal caries by increasing dentin formation to prevent pulpal exposure. Whereas the high sucrose diet impaired both the deposition and mineralization of the dentin matrix, glucocorticoids affected matrix formation only. These results indicate that the functional alterations in the pulpo-dentinal complex might contribute to dentinal caries progression in a cariogenic environment, irrespective of the causative mechanism

How many third molars remain unnoticed in a population survey without panoramic radiographs?

Abstract Objective: The aim of the study was to compare the findings of clinical examination and panoramic radiograph regarding the occurrence of third molars in a population survey to find out how many third molars remain clinically unnoticed. Materials and methods: A two-staged stratified cluster-sampling method was used to select 8028 participants representing the adult population aged 30 years and older. Clinical oral examinations and panoramic radiographs were carried out for 5989 subjects (46% men, 54% women; mean age 52.5, SD 14.6; range 30–97 years). Clinical recordings of the presence of third molars were compared with the radiographs. Statistics included chi-squared, Fisher’s, Wilcoxon’s, and Kruskal-Wallis tests. Results: In the 5989 subjects, 3742 third molars were recorded in the clinical examination, and 5912 were observed in the panoramic images, a difference of 2170 teeth. Furthermore, related to 3668 (61%) of the third molars, both clinical and radiographic recordings were attributed to the same third molar, while 2244 third molars were observed only in the panoramic image, and 74 only in the clinical examination. In every age group, the mean number of third molars per subject was larger radiographically compared with the clinical recordings (means for all 0.99 vs. 0.62; P < 0.001). Conclusion: Numbers of third molars, recorded in clinical examination alone, are underreported by approximately one-third compared with radiographic findings. Clinical relevance: The numbers of third molars in a population survey without a panoramic radiograph do not reflect the total number of third molars in a population

Twelve unidentified skeletons as remains of an epidemic or famine in Northern Finland

Abstract Skeletal remains of 12 individuals were found in a grave in a tar-burning pit. There were no coffins or other belongings to help with identification or reveal the cause of death. Methods: Forensic osteological and odontological methods were used to establish sex, age and height. Histological and chemical tests, including the determination of C-14 content, were applied to dating the skeletal remains. Results: Out of 12 skeletons, 8 were adults; 5 females, 2 males and 1 probable female. Four skeletons belonged to children (ages 1–12 years). The bones had been in the grave for more than 100 years as concluded from the deterioration of the distal parts, embrittling of the surface to 1 mm depth. C-14 results gave the radiocarbon years 95 +/- 65 Bp (before present, i.e., 1950). The calibrated years correspond to two time periods, 1670–1780 AD and 1798–1944 AD, as a possible period of death. Conclusions: Starvation and illnesses are the most plausible explanations for the deaths. Historical studies show that during the 17th and 19th centuries, there were famines in Finland accompanied by severe infections (severe famines in the years 1866–1868 and 1696–1697), forcing a lot of people to leave their homes

Retained dental roots of adults:a nationwide population study with panoramic radiographs

Abstract The aim of this study was to assess the occurrence and nature of retained dental roots and their associations with demographics in the Finnish adult population. From the cross-sectional nationwide Health 2000 Survey of the Finnish population aged 30 years and older, 6005 participants with clinical oral examination and panoramic radiographs were included. Occurrence and characteristics of all retained dental roots were examined. Statistical analyses included χ2, Kruskal–Wallis and Mann–Whitney U tests, and SAS-SUDAAN calculations. The mean age of the 6005 participants (46% men and 54% women) was 53 (SD 14.6) years. At least one retained dental root was observed in 13% (n = 754) of the participants. The 1350 retained roots included 461 (34%) roots retained entirely in bone and 889 (66%) partly in bone. The most common location of a retained dental root was the third molar region. Occurrence of retained roots partly in bone was associated with male sex and lower education. Occurrence of retained third molar roots entirely in bone was associated with female sex, younger age, higher education, and living in a city. Among all retained dental roots, the preponderance of third molars emphasized the demanding nature of extracting the third molar in women

Genetic variation on the BAT1-NFKBIL1-LTA region of major histocompatibility complex class III associates with periodontitis

Periodontitis is a chronic inflammatory disease with a multifactorial etiology. We investigated whether human major histocompatibility complex (MHC) polymorphisms (6p21.3) are associated with periodontal parameters. Parogene 1 population samples (n169) were analyzed with 13,245 single nucleotide polymorphisms (SNPs) of the MHC region. Eighteen selected SNPs (P&lt;0.001) were replicated in Parogene 2 population samples (n339) and the Health 2000 Survey (n1,420). All subjects had a detailed clinical and radiographic oral health examination. Serum lymphotoxin- (LTA) concentrations were measured in the Parogene populations, and the protein was detected in inflamed periodontal tissue. In the Parogene 1&nbsp; population, 10 SNPs were associated with periodontal parameters. The strongest associations emerged from the parameters bleeding on probing (BOP) and a probing pocket depth (PPD) of&gt;6mmwith the genes BAT1, NFKBIL1, and LTA. Six SNPs, rs11796, rs3130059, rs2239527, rs2071591, rs909253, and rs1041981 (r2,&gt;0.92), constituted a risk haplotype. In the Parogene 1 population, the haplotype had the strongest association with the parameter BOP, a PPD of&gt;6 mm, and severe periodontitis with odds ratios (95% confidence intervals) of 2.63 (2.21 to 3.20), 2.90 (2.37 to 3.52), and 3.10 (1.63 to 5.98), respectively. These results were replicated in the other two populations. High serum LTA concentrations in the Parogene population were associated with the periodontitis risk alleles of the LTA SNPs (rs909253 and rs1041981) of the haplotype. In addition, the protein was expressed in inflamed gingival connective tissue. We identified a novel BAT1-NFKBIL1-LTA haplotype as a significant contributor to the risk of periodontitis. The genetic polymorphisms in the MHC class III region may be functionally important in periodontitis susceptibility.</p