The Role of Cytokines Produced via the NLRP3 Inflammasome in Mouse Macrophages Stimulated with Dental Calculus in Osteoclastogenesis.

Dental calculus (DC) is a common deposit in periodontitis patients. We have previously shown that DC contains both microbial components and calcium phosphate crystals that induce an osteoclastogenic cytokine IL-1ß via the NLRP3 inflammasome in macrophages. In this study, we examined the effects of cytokines produced by mouse macrophages stimulated with DC on osteoclastogenesis. The culture supernatants from wild-type (WT) mouse macrophages stimulated with DC accelerated osteoclastogenesis in RANKL-primed mouse bone marrow macrophages (BMMs), but inhibited osteoclastogenesis in RANKL-primed RAW-D cells. WT, but not NLRP3-deficient, mouse macrophages stimulated with DC produced IL-1ß and IL-18 in a dose-dependent manner, indicating the NLRP3 inflammasome-dependent production of IL-1ß and IL-18. Both WT and NLRP3-deficient mouse macrophages stimulated with DC produced IL-10, indicating the NLRP3 inflammasome-independent production of IL-10. Recombinant IL-1ß accelerated osteoclastogenesis in both RANKL-primed BMMs and RAW-D cells, whereas recombinant IL-18 and IL-10 inhibited osteoclastogenesis. These results indicate that DC induces osteoclastogenic IL-1ß in an NLRP3 inflammasome-dependent manner and anti-osteogenic IL-18 and IL-10 dependently and independently of the NLRP3 inflammasome, respectively. DC may promote alveolar bone resorption via IL-1ß induction in periodontitis patients, but suppress resorption via IL-18 and IL-10 induction in some circumstances.

The effect of miniaturized manual versus mechanical instruments on calculus removal and root surface characteristics: An in vitro light microscopic study.

Objectives: The aim of this study was to evaluate by light microscopy analysis the effect of the use of miniaturised piezoelectric tips versus mini-five area specific curets on calculus removal and postoperative root surface alterations. Methods: A total of 20 extracted teeth were used. Two square surfaces (5×5 mm) were marked on each root surface with a diamond bur mounted on a high-speed handpiece. Before and after instrumentation, a series of magnified images (4.2×) of each experimental surface were taken with a standardized approach. According to a randomization list, the two surfaces on each sample were instrumented in a standardised fashion either with a mine-five curet or a slim piezoelectric tip. The images were processed using an imaging software. Data were summarised as means and standard deviations for the two outcomes (calculus and alterations.) at each time (pre and post) for both of the groups (manual and mechanical). Results: Both manual and mechanical instrumentation significantly reduced the calculus deposits (p < .001) without significant differences between the two groups. Both manual and mechanical treatments significantly increased alterations (p < .01). There was a statistically significant evidence of a greater increase in alterations from mechanical treatment. Conclusions: Slim mechanical piezoelectric tips and manual mini-five area-specific curets have similar effects on calculus removal. Manual instrumentation results in a more homogeneous postoperative root surface with less root alterations.

Do dental calculi predict the presence of renal stones?

OBJECTIVE: Pathological calcifications that occur in various parts of the body may cause stone formation over time. The structure of these stones is similar in many regions of the body. We have studied the relationship between dental calculi and kidney stones. MATERIAL AND METHODS: A total of 183 patients with dental stone complaints or dental calculi were included between April and August 2016 in the Cagri Dental Hospital, Elazig, Turkey. Patients were evaluated with regard to a urinary tract ultrasonography, urinalysis, oral hygiene, and stone and surgical disease history. All information was statistically investigated. RESULTS: The age of the patients in the kidney stones group was significantly higher than the non-kidney stone patients (p < 0.05). In the group with kidney stones, the percentage of dental calculus formation was significantly higher than the group without stones (p < 0.05). In the groups with and without kidney stones, dental stone recurrence rates did not differ significantly (p < 0.05). Urinary pH was significantly lower in the group with stones than the group without stones (p < 0.05). CONCLUSIONS: During a physical examination, the formation of a visible stone, such as a dental calculus, may be an indicator of other types of stones, such as kidney stones, and this should be further investigated.

Tooth grooves, occlusal striations, dental calculus, and evidence for fiber processing in an Italian eneolithic/bronze age cemetery.

OBJECTIVES: We conducted a systematic macroscopic and microscopic examination of occlusal and para-occlusal wear in a large dental sample (n = 3,014) from 217 individuals dated to the Early Bronze age site of Gricignano d'Aversa, Italy. We used macroscopic and microscopic techniques to document nondietary occlusal and para-occlusal wear and to analyze calculus inclusions in some of the teeth. In combining an analysis of the wear with the calculus inclusions we linked the specific wear to the likely fiber that was involved in producing it. MATERIALS AND METHODS: Teeth and their high resolution epoxy casts were analyzed through SEM and reflected light microscopes. Nineteen individuals (fifteen with activity induced dental modifications and four as a control sample) were examined for the presence of calculus inclusions. RESULTS: Activity induced dental modifications (AIDMs), notches, grooves and micro-striations, were found in the 62.2% of the adult females, in 21.2% of the adults of unknown sex and in a single male. We found the full spectrum of dental manipulations from very minor nonocclusal wear in some young individuals to severe attrition at the other extreme. The width of the striations and grooves, mostly on the upper incisors, suggests a craft activity involving fibers and thread production and manipulation. From the dental calculus of two females with grooves and striations, we extracted three fragments of fibers, identified as hemp (Cannabis, sp.). Previously from Gricignano woven hemp fibers were found on both surfaces of a metal blade associated with a male burial. DISCUSSION: This study found the co-occurrence of tooth AIDMs and the actual fibers preserved in the dental calculus. As more work is done analyzing dental calculus in a variety of humans, it is apparent that this biological material holds rich resources documenting non-dietary habits.

Salivary Levels of IL-6 and IL-17 Could Be an Indicator of Disease Severity in Patients with Calculus Associated Chronic Periodontitis.

Background/Purpose. Chronic periodontitis is an inflammatory disease of gums that causes loss of supporting structures of teeth, that is, gingiva, periodontal ligament, cementum, and alveolar bone. Levels of various cytokines in the serum, gingival tissues, and gingival crevicular fluid in patients with chronic periodontitis have been studied, but limited data are available on the level of cytokines in saliva. Therefore, a study was designed to determine levels of salivary IL-6 and IL-17 in patients with calculus associated chronic periodontitis. Materials and Methods. It was a comparative, cross-sectional study that is comprised of 41 healthy controls and 41 calculus associated chronic periodontitis patients (CP patients). According to the degree of attachment loss, CP patients were subcategorized as mild (CAL 1-2 mm), moderate (CAL 3-4 mm), and severe (CAL > 5 mm) forms of periodontitis. Salivary levels of IL-6 and IL-17 were determined using enzyme-linked immunosorbent assay (ELISA) technique. Data was analyzed using SPSS 20.0. Results. Between healthy controls and CP patients (moderate and severe disease), a statistically significant difference was observed in the concentrations of IL-6 and IL-17. In CP patients, the highest mean ± SD of salivary IL-6 and IL-17 was observed in severe CP, followed by moderate and mild CP. Regarding level of IL-6, a statistically significant difference was observed between mild and severe disease and between moderate and severe subcategories of CP patients. Similarly, statistically significant difference was observed in the level of IL-17 between mild and moderate, mild and severe disease, and moderate and severe disease. Conclusion. The levels of salivary IL-6 and IL-17 were increased significantly in calculus associated CP patients as compared to healthy controls and these levels increased with the progression of CP. Clinical Significance. Salivary levels of IL-6 and IL-17 may help in the subcategorization of CP.

Alpha-synuclein is present in dental calculus but not altered in Parkinson's disease patients in comparison to controls.

INTRODUCTION: In autopsy cases staged for sporadic Parkinson's disease (PD), the neuropathology is characterized by a preclinical phase that targets the enteric nervous system of the gastrointestinal tract (GIT). Therefore, the ENS might be a source of potential (presymptomatic) PD biomarkers. METHODS: In this clinically based study, we examined the alpha-synuclein (αSyn) concentration in an easily accessible protein storage medium of the GIT, dental calculus, in 21/50 patients with PD and 28/50 age- and gender-matched controls using ELISA. RESULTS: αSyn was detectable in dental calculus and the median concentration in the control patients was 8.6 pg/mg calculus (interquartile range 2.6-13.1 pg/mg). αSyn concentrations were significantly influenced by blood contamination and samples with a hemoglobin concentration of > 4000 ng/mL were excluded. There was no significant difference of αSyn concentrations in the dental calculus of PD patients (5.76 pg/mg, interquartile range 2.91-9.74 pg/mg) compared to those in controls (p = 0.40). CONCLUSION: The total αSyn concentration in dental calculus is not a suitable biomarker for sporadic PD. Disease-related variants such as oligomeric or phosphorylated αSyn in calculus might prove to be more specific.

Association of gingivitis with dental calculus thickness or dental calculus coverage and subgingival bacteria in feline leukemia virus- and feline immunodeficiency virus-negative cats.

Periodontal disease is the most common oral disease in cats. The objectives of this study were to determine the relationships between gingivitis and dental calculus thickness (DCT), or dental calculus coverage (DCC); determine the association of gingivitis scores and types of oral bacteria; and to evaluate bacterial co-infection in cats with periodontal disease. Twelve cats that were not infected with feline leukemia or feline immunodeficiency viruses were enrolled in the study. Gingivitis, DCT, and DCC were scored and recorded. A Kruskal-Wallis test was used to compare scores among canine, 2nd premolar, 3rd premolar, 4th premolar, and 1st molar teeth. The relationship between gingivitis and DCT or DCC scores was determined using the Spearman rank sum test (ρ). Subgingival bacteria were cultured and the association between bacterial species and gingivitis score was evaluated using a Fisher's exact test. The average gingivitis, DCT, and DCC scores for the caudal maxillary teeth were higher for the caudal mandibular teeth and more severe for the 3rd premolar, 4th premolar, and 1st molar teeth than for the canine teeth. A strong relationship between average DCT or DCC score and average gingivitis score was found (ρ = 0.96 and 1, respectively). Aerobic and anaerobic bacterial infections were identified in a large number of cats with periodontal disease (71.1% and 28.9%, respectively). In conclusion, severe gingivitis scores were associated with anaerobic bacterial infection. The caudal teeth are affected with more severe gingivitis, DCT, and DCC than the other teeth. Antibiotic prophylaxis should be prescribed in cats with periodontal disease.

La maladie parodontale est la maladie orale la plus fréquente chez les chats. Les objectifs de la présente étude étaient de déterminer les relations entre la gingivite et l'épaisseur du tartre dentaire (ETD), ou la couverture du tartre dentaire (CTD); déterminer l'association des pointages de gingivite et les types de bactéries orales; et d'évaluer les co-infections bactériennes chez les chats avec maladie parodontale. Douze chats qui n'étaient pas infectés par le virus de la leucémie féline ou le virus de l'immunodéficience féline ont été recrutés pour cette étude. La gingivite, l'ETD, et la CTD ont été évalués et notés. Un test de Kruskal-Wallis a permis de comparer les pointages parmi les dents canines, 2e prémolaires, 3e prémolaires, 4e prémolaires et 1ère molaires. La relation entre la gingivite et les pointages d'ETD ou de CTD a été déterminée à l'aide du test de corrélation de Spearman (ρ). Les bactéries sous-gingivales ont été cultivées et l'association entre les espèces bactériennes et le pointage de gingivite a été évaluée à l'aide du test exact de Fisher. Les pointages moyens de gingivite, d'ETD, et de CTD pour les dents maxillaires caudales étaient plus élevés que pour les dents mandibulaires caudales et plus sévères pour les dents 3e prémolaires, 4e prémolaires, et 1ère molaires que pour les canines. Une forte relation entre les pointages moyens d'ETD et de CTD et les pointages moyens de gingivite a été trouvée (ρ = 0,96 et 1, respectivement). Des infections bactériennes aérobies et anaérobies ont été identifiées chez un grand nombre de chats avec maladie parodontale (71,1 % et 28,9 %, respectivement). En conclusion, des pointages élevés de gingivite étaient associés avec des infections par des bactéries anaérobiques. Les dents caudales étaient plus sévèrement affectées de gingivite, d'ETD, et de CTD que les autres dents. Une antibiothérapie prophylactique devrait être prescrite pour des chats avec maladie parodontale.(Traduit par Docteur Serge Messier).

Miniature endoscopic optical coherence tomography for calculus detection.

The effective treatment of periodontitis involves the detection and removal of subgingival dental calculus. However, subgingival calculus is more difficult to detect than supragingival calculus because it is firmly attached to root surfaces within periodontal pockets. To achieve a smooth root surface, clinicians often remove excessive amounts of root structure because of decreased visibility. In addition, enamel pearl, a rare type of ectopic enamel formation on the root surface, can easily be confused with dental calculus in the subgingival environment. In this study, we developed a fiber-probe swept-source optical coherence tomography (SSOCT) technique and combined it with the quantitative measurement of an optical parameter [standard deviation (SD) of the optical coherence tomography (OCT) intensity] to differentiate subgingival calculus from sound enamel, including enamel pearl. Two-dimensional circumferential images were constructed by rotating the miniprobe (0.9 mm diameter) while acquiring image lines, and the adjacent lines in each rotation were stacked to generate a three-dimensional volume. In OCT images, compared to sound enamel and enamel pearls, dental calculus showed significant differences (P<0.001) in SD values. Finally, the receiver operating characteristic curve had a high capacity (area under the curve=0.934) for discriminating between healthy regions (including enamel pearl) and dental calculus.

Non-Invasive Periodontal Probing Through Fourier-Domain Optical Coherence Tomography.

BACKGROUND: Periodontitis is a multifactorial and infectious disease that may result in significant debilitation. The aim of this study is to exploit two optical coherence tomography (OCT) systems operating in the Fourier domain at different wavelengths, 930 and 1,325 nm, for structural analysis of periodontal tissue in porcine jaws. METHODS: Five fresh porcine jaws were sectioned and stored in formalin before OCT analysis. Two- and three-dimensional OCT images of the tooth/gingiva interface were performed, and measurements of the gingival structures were obtained. The 930-nm OCT system operates in the spectral domain, whereas the 1,325-nm system is a swept-source model. Stereomicroscope images, the gold standard, were used for direct comparison. RESULTS: Through image analysis, it is possible to identify the free gingiva and the attached gingiva, the calculus deposition over tooth surfaces, and the subgingival calculus that enables the enlargement of the gingival sulcus. In addition, the gingival thickness and the gingival sulcus depth can be non-invasively measured, varying from 0.8 to 4 mm. CONCLUSIONS: Regarding the ability of the two OCT systems to visualize periodontal structures, the system operating at 1,325 nm shows a better performance, owing to a longer central wavelength that allows deeper tissue penetration. The results with the system at 930 nm can also be used, but some features could not be observed due to its lower penetration depth in the tissue.

To meat or not to meat? New perspectives on Neanderthal ecology.

Neanderthals have been commonly depicted as top predators who met their nutritional needs by focusing entirely on meat. This information mostly derives from faunal assemblage analyses and stable isotope studies: methods that tend to underestimate plant consumption and overestimate the intake of animal proteins. Several studies in fact demonstrate that there is a physiological limit to the amount of animal proteins that can be consumed: exceeding these values causes protein toxicity that can be particularly dangerous to pregnant women and newborns. Consequently, to avoid food poisoning from meat-based diets, Neanderthals must have incorporated alternative food sources in their daily diets, including plant materials as well.

Histological and profilometric evaluation of the root surface after instrumentation with a new piezoelectric device - ex vivo study.

OBJECTIVES: An ex vivo model was designed to profilometrically and histologically assess root changes resulting from scaling with a new ultrasonic device, designed for bone piezoelectric surgery, in comparison with curettes. METHODS: Three groups of 10 periodontal hopeless teeth were each subjected to different root instrumentation: Gracey curettes (CUR); ultrasonic piezoelectric device, Perio 100% setting, level 8 (P100); and ultrasonic piezoelectric device Surg 50% setting, level 1 (S50). After extraction, all teeth were photographed to visually assess the presence of dental calculus. The treated root surfaces were profilometrically evaluated (Ra, Rz, Rmax). Undecalcified histological sections were prepared to assess qualitative changes in cementum thickness. Statistical analysis was carried out using one-way anova test with a significance level of 95%. RESULTS: Both instruments proved to be effective in the complete removal of calculus. The CUR group presented the lowest Ra [2.28 µm (±0.58)] and S50 the highest [3.01 µm (±0.61)]. No statistically significant differences were detected among the three groups, for Ra, Rz and Rmax. Histologically, there was a cementum thickness reduction in all groups, being higher and more irregular in S50 group. CONCLUSIONS: Within the limits of this study, there were no statistically significant differences in roughness parameters analyzed between curettes and the ultrasonic piezoelectric unit. This new instrument removes a smaller amount of cementum, mainly at the Perio 100% power setting, which appears to be the least damaging. The ultrasonic device is effective in calculus removal, proving to be as effective as curettes.

Effects of root surface debridement using Er:YAG laser versus ultrasonic scaling - a SEM study.

OBJECTIVE: Despite promising results of Er:YAG laser in periodontal debridement, to date there is no consensus about the ideal settings for clinical use. This experimental clinical trial aimed to determine the effects of debridement using Er:YAG laser and to compare with ultrasonic treatment. MATERIALS AND METHODS: Sixty-four teeth were divided into two in vivo and in vitro subgroups. Each tooth received ultrasonic treatment on one side and Er:YAG laser debridement at either 60, 100, 160 or 250 mJ pulse(-1) and at 10 Hz on the other side on a random basis. All samples were morphologically analyzed afterwards under scanning electron microscope for surface changes and dentinal tubules exposure. Treatment duration (d) was also recorded. RESULTS: Laser debridement produced an irregular, rough and flaky surface free of carbonization or meltdown while ultrasound produced a relatively smoother surface. The number of exposed dentinal tubules (n) followed an energy-dependent trend. The number of exposed tubules among the in vivo laser groups was n 60 mJ = n 100 mJ < n 160 mJ < n 250 mJ (P < 0.001). Also 160 and 250 mJ lasers led to significantly more dentinal exposure than ultrasound under in vivo condition. Within the in vitro laser groups, dentinal tubules exposure was n 60 mJ < n 100 mJ < n 160 mJ < n 250 mJ (P ≤ 0.0015). Furthermore, in vitro laser treatments at 100, 160 and 250 mJ led to significantly more dentinal denudation than ultrasound. Treatment duration (d) for the in vivo groups was d 60 mJ > d 100 mJ > d Ultrasound = d 160 mJ > d 250 mJ (P ≤ 0.046), while for the in vitro groups it was d 60 mJ > d 100 mJ = d Ultrasound = d 160 mJ >d 250 mJ (P ≤ 0.046). CONCLUSIONS: Due to excessive treatment duration and surface damage, Er:YAG laser debridement at 60 and 250 mJ pulse(-1), respectively, is not appropriate for clinical use. Although laser debridement at 100 and 160 mJ pulse(-1) seems more suitable for clinical application, compared to ultrasound the former is more time-consuming and the latter is more aggressive. Using a feedback device or lower pulse energies are recommended when using laser in closed field.

Dental calculus is associated with death from heart infarction.

OBJECTIVES: We studied whether the amount of dental calculus is associated with death from heart infarction in the dental infection-atherosclerosis paradigm. MATERIALS: Participants were 1676 healthy young Swedes followed up from 1985 to 2011. At the beginning of the study all subjects underwent oral clinical examination including dental calculus registration scored with calculus index (CI). Outcome measure was cause of death classified according to WHO International Classification of Diseases. Unpaired t-test, Chi-square tests, and multiple logistic regressions were used. RESULTS: Of the 1676 participants, 2.8% had died during follow-up. Women died at a mean age of 61.5 years and men at 61.7 years. The difference in the CI index score between the survivors versus deceased patients was significant by the year 2009 (P < 0.01). In multiple regression analysis of the relationship between death from heart infarction as a dependent variable and CI as independent variable with controlling for age, gender, dental visits, dental plaque, periodontal pockets, education, income, socioeconomic status, and pack-years of smoking, CI score appeared to be associated with 2.3 times the odds ratio for cardiac death. CONCLUSIONS: The results confirmed our study hypothesis by showing that dental calculus indeed associated statistically with cardiac death due to infarction.

Reliability of direct and indirect clinical attachment level measurements.

AIMS: To investigate the influence of subject-, tooth- and site-level characteristics on intra-examiner reproducibility of direct and indirect clinical attachment level (CALDIR and CALIND ) recordings, and to quantify the impact of less-than-perfect reliability on our ability to assess periodontitis progression. MATERIALS AND METHODS: Within a 1-week interval, a single examiner performed duplicate probing depth (PD), CALDIR and gingival recession (GR) recordings in six sites of all teeth present in 148 periodontitis patients. CALIND was calculated on the basis of the PD and GR. RESULTS: Agreement was observed in 65%, 62%, 69% and 84% of the duplicate CALDIR , CALIND , PD and GR recordings, respectively, and >95% of the differences were within ±1 mm. This study identified multiple predictors for CAL measurement errors ≥1 mm, including tooth and site location, presence of supra- and subgingival calculus, bleeding on probing and suppuration. Measurement errors were more likely in patients diagnosed with "extensive" rather than "less extensive" periodontitis. In over half of the patients, measurement error frequencies were too high to allow for detection of possible CAL changes ≥2 mm with a false-positive rate ≤5%. Detection of CAL changes with low false-positives was more likely using recordings obtained by the direct method. CONCLUSIONS: From a measurement error point of view, CALDIR recordings are preferable over CALIND .

Dental disease in slender lorises (Loris tardigradus).

Necropsies were performed in 25 slender lorises (Loris tardigradus) from a colony at Bochum University. In seven adult individuals, teeth were missing, loose, or severely affected by dental calculus. In one of these cases, a severe periodontal disease was seen without abscess formation. In another four lorises purulent/gangrenous inflammation was found next to the teeth either in the maxillary or the mandibular region.

A comparison of root surface instrumentation using manual, ultrasonic and rotary instruments: an in vitro study using scanning electron microscopy.

BACKGROUND: The commonly accepted idea concerning root planing is that excessive removal of cementum is not necessary for removal of endotoxins. The ideal instrument should enable the removal of all extraneous substances from the root surfaces, without causing any iatrogenic effects. AIM: To compare the remaining calculus, loss of tooth substance, and roughness of root surface after root planing with Gracey curette, ultrasonic instrument (Slimline insert FSI-SLI-10S), and DesmoClean rotary bur. MATERIALS AND METHODS: The efficiency of calculus removal, the amount of lost tooth substance, and root surface roughness resulting from the use of hand curette, ultrasonic instrument, and rotary bur on 36 extracted mandibular incisors were examined by SEM. We used three indices to measure the changes: Remaining calculus index (RCI), Loss of tooth substance index (LTSI), and Roughness loss of tooth substance index (RLTSI). Twelve samples were treated with each instrument. The time required for instrumentation was also noted. STATISTICAL ANALYSIS: Kruskal-Wallis ANOVA was used for multiple group comparisons and the Mann-Whitney test for group-wise comparisons. Analysis was carried out with SPSS software (version 13). RESULTS AND CONCLUSION: The RCI and LTSI showed nonsignificant differences between the three groups. RLTSI showed a significant difference between Slimline and hand curette as well as Slimline and Desmo-Clean. Slimline showed the least mean scores for RCI, LTSI, and RLTSI. Thus, even though the difference was not statistically significant, Slimline insert was shown to be better than the other methods as assessed by the indices scores and the instrumentation time.

Influence of dental exposure to oral environment on smear layer removal and collagen exhibition after using different conditioning agents.

Although in vitro studies have shown encouraging results for root surface conditioning with demineralizing agents, in vivo studies have failed to show its benefits in periodontal healing. This can be attributed to several factors, among which, the hypermineralization of dental surface. Therefore, this in vitro study compared, using scanning electron microscopy (SEM), the effect of root surface conditioning with different conditioners (1% and 25% citric acid, 24% EDTA and 50 mg/mL tetracycline hydrochloride) in impacted teeth and in teeth that had their roots exposed to the oral environment. One trained examiner assessed the SEM micrographs using a root surface modification index. There was a tendency of more root surface modification in the group of impacted teeth, suggesting that the degree of root mineralization influences its chemical demineralization.

Dento-alveolar lesions and palaeodietary inferences from the Paso Alsina 1 site (eastern Pampean-Patagonian transition, Argentina).

Several archaeological researches in northeastern Patagonia and southeastern Pampas have evaluated various indicators of the diets of hunter-gatherers who inhabited these regions during the Late Holocene, including the role of plant foods. Dental analysis is an important way to introduce new information about subsistence. In this sense, the objective of this work is to document and interpret dento-alveolar lesions in an osteological sample recovered from the Paso Alsina 1 archaeological site (eastern Pampean-Patagonian transition, Argentina). This paper will explore the oral health status of individuals and discuss palaeodietary information of hunter-gatherers that inhabited the lower valley of the Colorado River during the final Late Holocene (ca. 500 years BP). The site is defined as a formal area bundle composed of 10 secondary multiple burials containing 56 individuals of both sexes and various ages (e.g., perinatal, infant, and adult). In this study, 781 teeth and 1036 alveoli from 47 maxillae and 38 mandibles were analysed from 51 adult individuals. The results indicate a moderate rate of dental wear, and dental calculus, and low percentages of caries, abscesses, and antemortem tooth loss. The information obtained suggests a diet based on a combination of proteins, fat and carbohydrates. Results are then compared with those from other lines of analysis for the study area and for the neighboring regions (northeastern Patagonia and southeastern Pampas).

Near-ultraviolet removal rates for subgingival dental calculus at different irradiation angles.

The laser ablation rate of subgingival dental calculus irradiated at a 400-nm-wavelength, 7.4-mJ pulse energy, and 85- and 20-deg irradiation angles is measured using laser triangulation. Three-dimensional images taken before and after irradiation create a removal map with 6-µm axial resolution. Fifteen human teeth with subgingival calculus are irradiated in vitro under a cooling water spray with an ∼300-µm-diam, tenth-order super-gaussian beam. The average subgingival calculus removal rates for irradiation at 85 and 20 deg are 11.1±3.6 and 11.5±5.9 µm∕pulse, respectively, for depth removal and 4.5±1.7×10(5) and 4.8±2.3×10(5) µm(3)∕pulse, respectively, for volume removal. The ablation rate is constant at each irradiation site but varies between sites because of the large differences in the physical and optical properties of calculus. Comparison of the average depth- and volume-removal rates does not reveal any dependence on the irradiation angle and is likely due to the surface topology of subgingival calculus samples that overshadows any expected angular dependence.

Subgingival calculus imaging based on swept-source optical coherence tomography.

We characterized and imaged dental calculus using swept-source optical coherence tomography (SS-OCT). The refractive indices of enamel, dentin, cementum, and calculus were measured as 1.625 ± 0.024, 1.534 ± 0.029, 1.570 ± 0.021, and 2.097 ± 0.094, respectively. Dental calculus leads strong scattering properties, and thus, the region can be identified from enamel with SS-OCT imaging. An extracted human tooth with calculus is covered with gingiva tissue as an in vitro sample for tomographic imaging.