Morphological and functional features of cat teeth

Background: The oral cavity is considered as a complex ecological niche, its complex microbial community is reflected to it. Streptococcus mutans has been implicated as one of the major etiological factor of dental caries. Tooth surfaces colonized with Streptococcus mutans are at a higher risk for developing caries, while lactobacilli are considered as the secondary invaders, not initiators of the carious lesion. The main purpose of this study was to correlate the dental caries (for primary and permanent teeth) in the upper jaw with the streptococcus mutans and lactobacilli count in the dental plaque and saliva, also to correlate the dental caries (for primary and permanent teeth) in the lower jaw with the streptococcus mutans and lactobacilli count in the saliva. Materials and methods: Forty seven children aged 5-9 years old were selected for this study. Dental caries recording was carried out by the dmfs index (decayed, missed, filled surfaces for primary teeth) to inspect the primary teeth and DMFS index (decayed, missed, filled surfaces for permanent teeth) to inspect the permanent teeth, by using the dental mirror and explorer. Collection of salivary samples was performed in the morning between (10-11) a.m. at least one hour after breakfast, then normal saline was added to have tenfold dilutions, for the purpose of full colony counting of the caries related microorganisms (streptococcus mutans and lactobacilli), then inoculation was done in the special selective media (for the streptococcus mutans is Mitis-Salivarius-Bacitracin agar, and for the lactobacilli is Rogosa agar). Counting of the colonies of the bacteria were estimated by the aid of dissection microscope Results: The highest level of dmfs means was found in primary upper teeth, it was 17.6383 ± 10.10 while for the permanent teeth the mean of DS and DMFS was highest in the lower teeth, it was 0.7391 ± 1. Pearson correlation was used to show the correlation between the ds and dmfs of upper and lower primary teeth with the level of streptococcus mutans in saliva (sm. Sal) and lactobacillus in saliva ,there was a significant correlation between the ds and dmfs for upper primary teeth at level 0.01 (2-tailed), and there was negative correlation between dsl and level of streptococcus mutans in saliva (sm. Sal) also there was negative correlation between dmfs for upper and lower primary teeth with level of streptococcus mutans in saliva, also the correlation between lactobacillus level in plaque with streptococcus level in plaque was negative, while for upper permanent teeth the correlation was negative with both type of bacteria level in plaque with the DSU and DMFSU Conclusion: The caries activity was more prominent in upper teeth than lower teeth, levels of streptococcus mutans were not associated with high caries activity, which emphasizes and consistent with the fact that the dental caries is a multifactorial disease, related to many factors.

Penetration of radiocalcium at the margins of resin and glass ionomer dentine bonding agents in primary and permanent teeth

To quantify M1 and M2 macrophages in radicular cysts of permanent (n=14 cases) and primary teeth (n=15 cases). All patients who attended the School of Dentistry Ribeirão Preto, University of São Paulo with primary teeth or permanent molars that were scheduled for extraction and fulfilled the inclusion criteria: absence of pain; presence/absence of fistulae; extensive coronal destruction due to caries lesions without possibility of restoration; pulp necrosis; radiographically visible apical periodontitis; and no previous treatment, were selected. The radicular cysts were removed and subsequently submitted to histopathologic analysis in order to classify the type of inflammatory infiltrate. In addition, CD68 (M1+, M2+) and CD163 (M1-, M2+) markers were quantified through an immunohistochemistry analysis. The data acquired were submitted to a Mann-Whitney test, with a 5% significance level. The patients had a mean age of 38.6years and 5.9years for cysts associated with permanent and primary teeth, respectively. In the histopathological analysis, no significant difference (P=0.87) was found between radicular cysts in primary and permanent teeth regarding the intensity of the chronic inflammatory infiltrate. A significantly greater prevalence of M2 macrophages (P<0.05) was observed in the lesions of both permanent and primary teeth, even though both M1 and M2 macrophages were detected. No significant difference (P>0.05) was found for M1 and M2 macrophages associated with the cysts of primary and permanent teeth. M1 and M2 macrophages were present in radicular cysts associated with primary and permanent teeth, with a greater quantity of M2 cells. The immunophenotypic quantification of M1 and M2 macrophage polarization in radicular cysts associated with primary and permanent teeth were similar.

This study was conducted to analyze the ablation rate and micromorphological aspects of microcavities in enamel and dentin of primary and permanent teeth using a Er: YAG laser system. Micromorphological evaluation has been performed in terms of permanent teeth; however, little information about Er: YAG laser interaction with primary teeth can be found in the literature. Because children have been the most beneficiary patients with laser therapy in our offices, it is extremely necessary to compare the effects of this kind of laser system on the enamel and dentin of permanent and primary teeth. In this study, we used eleven intact primary anterior exfoliated teeth and six extracted permanent molar teeth. We used a commercial laser system: a Er: YAG Twin Light laser system (Fotona Medical Lasers, Slovenia) at 2940 nm, changing average energy levels per pulse (100, 200, 300, and 400 mJ) producing 48 microcavities in enamel and dentin of primary and permanent teeth. Primary teeth are more easily ablated than are permanent teeth, when related to enamel or dentin. However, while this laser system is capable of slowly revealing the enamel’s microstructure, in dentin only the lowest laser energies permit this kind of observation, more easily decomposing the original tissue aspect, when related to primary or permanent teeth. Statistically, the only different factor at the 5% level was an energy per pulse of 400 mJ, confirming the results found in SEM. Our results showed that dentin in both primary and permanent teeth is less resistant to Er: YAG laser ablation; this fact is easily observed under SEM observation and through the ablation rate evaluation.

Prediction of occlusion by measurements of the deciduous dentition

Comparison of shear bond strengths of orthodontic brackets bonded to deciduous and permanent teeth

The functional incisor teeth (permanent and deciduous teeth) from 13 species of Bovidae (16 specimens in all) were prepared for electronprobe microanalysis of Ca, P, and trace elements. The concentrations of calcium in the enamel layer of the permanent and deciduous teeth were constant at each level, in contrast to those in dentin layers, where the concentrations in permanent incisor teeth gradually decreased from the surface inward. Concentrations of magnesium (about 1-2 atoms %) in deciduous teeth gradually increased from the surface inward, in contrast to those in permanent teeth. Trace amounts of iron were found throughout the enamel layers, but the concentrations varied among species. The profiles of fluoride concentrations differed between deciduous and permanent teeth.Our chemical analysis of Ca, P, and trace elements (Mg, F, and Fe) indicates that some of the most important differences between the permanent and deciduous teeth of Bovidae might be those in the distributions of trace elements. These differences might be related to the mechanism of mineralizationin deciduous and permanent teeth.

Objectives:The consumption of carbonated beverages is one of the etiological factors that cause dental erosion. The purpose of this research was to compare changes in the microhardness of permanent and primary teeth after immersion in two types of carbonated beverages.Materials and Methods:This investigation was done on 30 healthy permanent molars and 30 healthy primary canines. Each group of primary and permanent teeth was subdivided into three groups of 10 teeth. The teeth was immersed in 40 ml of each of the three beverages for 5 min. One subgroup was immersed in water (as a control). The next was immersed in Lemon Delster and the last subgroup was immersed in Coca-Cola. The microhardness of enamel was measured using the Vickers method before and after immersion. Finally, the data was analyzed by paired t-test, one-way analysis of variance, and t-test.Results:Microhardness reduction in the primary teeth was significant in both the Lemon Delster and Coca-Cola groups (P < 0.05). This reduction was also statistically significant in the permanent teeth (P < 0.05). A comparison of the enamel changes in the primary teeth with permanent teeth after immersion in both beverages showed a greater microhardness reduction in the primary teeth in both the experimental groups.Conclusions:Coca-Cola and Lemon Delster caused a significant reduction of microhardness in tooth enamel. This reduction was greater in primary teeth than in permanent teeth, and was also greater after immersion in Coca-Cola than after immersion in Lemon Delster.

The present study aimed to meta-analyze and evaluate the certainty of evidence for resin infiltration of proximal carious lesions in primary and permanent teeth. While resin infiltration has been shown efficacious for caries management, the certainty of evidence remains unclear. The protocol was registered with PROSPERO (CRD42018080895), and PRISMA guidelines have been followed. The databases PubMed, Embase, and Cochrane CENTRAL were systematically screened, complemented by hand searches and cross-referencing. Eleven relevant articles were identified and included, i.e., randomized controlled trials (RCTs) comparing the progression of resin infiltrated proximal caries lesions (combined with non-invasive measures) in primary or permanent teeth with non-invasive measures. Random-effects meta-analyses and trial sequential analyses (TSA) were performed for per-protocol (PP), intention-to-treat (ITT), and best/worst case (BC/WC) scenarios. Six included trials assessed lesions in permanent teeth and five trails assessed lesions in primary teeth. The trials had a high or unclear risk of bias. Risk of caries progression was significantly reduced for infiltrated lesions in the PP, ITT, and BC scenarios in both permanent teeth and primary teeth, but not in the WC scenario. According to the TSA, firm evidence was reached for all of the scenarios except the WC. In conclusion, there is firm evidence for resin infiltration arresting proximal caries lesions in permanent and primary teeth.

BACKGROUND: Valuable structural and chemical properties can be obtained for dentin and enamel by vibrational spectroscopy. A better understanding of structural and chemical changes in deciduous dentition will contribute to improved dental restoration procedures for adolescents. OBJECTIVE: ATR-FTIR and Raman spectroscopy were applied to study human permanent and primary teeth. Slices were prepared from 10 German, 10 Turkish and 25 Jordanian teeth. METHODS: Raman images were collected at 785 nm excitation. FTIR images were collected using a germanium ATR accessory and focal plane array detector. Average Raman and infrared spectra were calculated for analysis. RESULTS: Our results showed that (i) the mineral to matrix ratio is lower in primary teeth than in permanent teeth, (ii) the carbonate to phosphate ratio was higher for primary teeth, (iii) crystallinity was lower in primary teeth, and (iv) collagen crosslinks occurred to be higher in primary teeth. FTIR and Raman data confirmed the results of each other. Deconvolution of the infrared band near 870 cm−1 reveals evidence for A2-type carbonate substitution on hydroxyapatite of primary teeth spectra in addition to the A and B type carbonate substitution that are also found in permanent teeth. CONCLUSIONS: Beside chemical and structural differences found between primary and permanent teeth, variations between the origin and age of the specimens were observed which requires further systematic investigations.

Compared with CR, there were lower numbers of failures with HT and SE in the primary dentition, and with SE and SW in the permanent dentition. Most studies showed high risk of bias and limited precision of estimates due to small sample size and typically limited numbers of failures, resulting in assessments of low or very low certainty of evidence for most comparisons.

Interceptive orthodontics may be indicated in puppies exhibiting dental malocclusion with linguoverted deciduous mandibular canine teeth to alleviate pain and prevent teeth interlock, which may affect growth and development of the mandibles. Historically extraction of deciduous mandibular canine teeth has been recommended as soon as a malocclusion is identified, often as early as 6-8 weeks of age and no later than 12 weeks of age. This early surgical intervention of deciduous teeth extractions risks potential damage to the developing permanent canine teeth resulting in enamel defects often referred to as a Turner's tooth or Turner's hypoplasia. A search of medical records from five veterinary specialty dentistry practices was conducted to identify dogs 8-12 weeks of age who (a) underwent deciduous mandibular canine extractions for management of class 1 or class 2 malocclusion with linguoverted mandibular canine teeth, and (b) were seen for at least one recheck exam to assess for enamel defects on permanent mandibular canine teeth. Furthermore, data was collected to determine the number of dogs that required additional treatment after eruption of the permanent canine teeth due to linguoversion of the permanent canine teeth. All procedures were performed by a board-certified veterinary dentist™ or a supervised veterinary dentistry resident. Seventy-four dogs fit the inclusion criteria and had a total of 143 deciduous mandibular canine teeth extracted, out of which 13 dogs exhibited enamel defects affecting 21 permanent canine teeth. The 13 affected dogs represent a 17.5% cumulative incident rate 13/74 (95%CI 11-28%). Of all extracted teeth, 14.6% (21/143) had enamel defects affecting permanent canine teeth. Twenty-eight dogs required additional treatment to prevent the permanent mandibular canine teeth from causing trauma to the hard palate and gingiva which represented 37.8% (28/74) of all dogs in the study. Age and sex of the dog at the time of extraction were not found to be associated with the likelihood of incidence of enamel defects. This is the first reported rate of enamel defects on permanent mandibular canine teeth following extraction of deciduous mandibular canine teeth and is important to consider when advising or performing extraction of deciduous teeth in dogs.

Primary tooth impaction is a rare phenomenon when compared to permanent teeth impaction. The purpose of this report is to present a 5-year-old Chinese girl who exhibited impaction of tooth 51, its unusual consequence on the permanent successor tooth and its comprehensive management. Her parents revealed that at 6 months of age, the patient had fallen from her bed and struck her face on the floor; however, there were no teeth present in the oral cavity. The intraoral examinations identified a bony-like projection on the buccal aspect of the alveolus in the 51 region. Radiographic examination revealed that tooth 51 exhibited an unfavourable orientation, with the crown directed towards the palate. Therefore, the impacted tooth 51 was surgically removed, and two years later tooth 11 erupted into the oral cavity with an indentation on its incisal aspect, which resembled the crown of the primary teeth, thus giving the appearance of a tooth within a tooth or 'dens in dente'. Subsequently, enameloplasty and composite resin build-up was performed on tooth 11 for aesthetic reasons. It is very unusual to have the clinical crowns of both primary and permanent teeth in such close proximity within the alveolar bone, and the present case is a good example to emphasize that trauma to the primary teeth is of considerable importance due to the close proximity of the primary teeth to permanent tooth germs.

An improved reagent for chemomechanical caries removal in permanent and deciduous teeth: an in vitro study

BackgroundUsing salivary microbiota as an accurate proxy for monitoring supragingival microbiota remains controversial because their relationship remains unclear. The eruption of permanent teeth and the exfoliation of primary teeth in mixed dentition greatly alter microbial habitats, which may cause compositional shifts of oral microbiota from childhood to adults.ObjectiveThis study’s purpose was to assess whether saliva represents a suitable sample for monitoring supragingival microbiota in healthy people, and to explore how the replacement process of deciduous teeth with permanent teeth in mixed dentition influences microbiota within the oral cavity.DesignSamples of saliva and of supragingival plaque from permanent and deciduous teeth were collected separately from 20 healthy children with mixed dentition. To characterize their microbial communities, we used the V3–V4 hypervariable region of the bacterial 16S rRNA gene sequence.ResultsSaliva harbored a less even and less diverse community than did the plaque. Discriminating genera, namely Rothia and Streptococcus, contributed to the saliva and plaque differentiation. About half of predicted KEGG pathways varied between the plaque and saliva communities. Oral bacteria showed significantly associations between their supragingival and salivary states. We identified 20 supragingival plaque-related genera in saliva, such as Corynebacterium, Capnocytophaga, Fusobacterium, and Neisseria. Additionally, the relative abundance of Actinobacteria peaked in the permanent teeth plaque but subsided in deciduous teeth plaque and saliva. The exfoliation of deciduous teeth and eruption of permanent teeth might be related to the reported fluctuation in the relative abundance of Actinobacteria from primary dentition to permanent dentition within the oral cavity. The variation between PT and DT was due mainly to permanent teeth being enriched in Actinomyces and deciduous teeth in Treponema.ConclusionThese results suggested that the supragingival plaque-related bacteria could be suitable candidates when sampling saliva for monitoring supragingival microbiota. The replacement process of deciduous teeth with permanent teeth in mixed dentition might be related to the reported age-maturation of phylum Actinobacteria in the oral cavity.