Study of Orthophosphate, Pyrophosphate, and Pyrophosphatase in Saliva With Reference to Calculus Formation and Inhibition

Prevalence of rapid calculus formers and its associated factors amongst patients visiting a dental hospital: a preliminary investigation

BACKGROUND

This study focuses on the determination and classification of patients as rapid or slowcalculusformersbasedontherateofcalculusformationafteroralprophylaxis. It also aims to determine the factors that positively impact the formation and deposition of calculus in patients and identify the factors that accelerate or decelerate the deposition of calculus.

METHODS

The study was conducted in the Department of Periodontology, Dr Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University Chandigarh, India. We examined 51 patients after a month of the oral prophylaxis, recorded the amount of calculus present in the oral cavity, and then recorded a detailed history which was briefly divided into Age, Sex, Residence, Oral habits, and maintenance of oral hygiene.

RESULTS

An evident and meaningful link was found between age and the rate at which dental calculus forms. The average age of individuals differed significantly between the rapid and slow calculus formers, which could be ascribed to the decline in manual dexterity as age increases, resulting in less effective oral hygiene habits, including toothbrushing. None of the other factors dietary and oral hygiene related could be identified distinctly, probably owing to the small sample of the study. The oral health status exhibited a significant difference between slow and rapid calculus formers.

CONCLUSIONS

Within the limitations of the study, the data analyzed, identified age as a significant determinant that impact the rate of formation of calculus in patients and reported a significant difference in the oral health status of rapid and slow calculus formers.

A Study of Oral Health Parameters and the Properties and Composition of Saliva in Oncological Patients with and without Medication-Related Osteonecrosis of the Jaw Who Take Bisphosphonates

Background and Objectives: The aim of this study was to examine how the status of the oral cavity, composition and properties of saliva change in oncological patients with and without Medication-Related Osteonecrosis of the Jaw (MRONJ) undergoing bisphosphonate therapy. Materials and Methods: A retrospective case-control study of 49 oncological patients using bisphosphonates (BPs) was conducted. The study population was divided into two groups-Group I consisted of 29 patients with MRONJ and Group II of 20 patients without MRONJ. The control group consisted of 32 persons without oncological history and without antiresorptive therapy. Standard dental examination included the assessment of the number of teeth remaining, teeth with caries and fillings, Approximal Plaque Index (API) and Bleeding on Probing (BOP). In terms of MRONJ, localization and stage were assessed. Laboratory tests of saliva included determination of pH and concentrations of Ca and PO₄ ions, total protein, lactoferrin, lysozyme, sIgA, IgA, cortisol, neopterin, activity of amylase at rest, and stimulated saliva. The buffering capacity and microbiological tests (Streptococcus mutans, Lactobacillus spp. load) of stimulated saliva were also determined. Results: There were no statistically significant differences between the selected oral parameters and saliva of Group I and Group II. Significant differences were found between Group I and the control group. BOP, lysozyme and cortisol concentration were higher, while the number of teeth with fillings, Ca and neopterin concentrations were lower in comparison to the control group. In Group I, a significantly higher percentage of patients with a high colony count (>10⁵) of Streptococcus mutans and Lactobacillus spp. was also found. The significant differences between Group II and the control group concerned the concentrations of lysozyme, Ca ions, sIgA, neopterin and the colony count of Lactobacillus spp. In the Group I patients who received a significantly higher cumulative dose of BP compared to the Group II, a significant positive correlation was found between the received BP dose and the BOP. Most MRONJ foci were stage 2 and were mainly located in the mandible. Conclusions: Among oncological patients with and without MRONJ undergoing BP therapy compared to the control group, there are statistically significant differences in the dental, periodontal and microbiological status and in the composition of the saliva. Particularly noteworthy are the statistically significant differences in the decreased level of Ca ions, the increased level of cortisol and the elements of saliva related to the immune response (lysozyme, sIgA, neopterin). Additionally, a higher cumulative dose of BPs may affect the susceptibility to the development of osteonecrosis of the jaws. Patients undergoing antiresorptive therapy should receive multidisciplinary medical care, including dental care.

Εffect of cleansers on the composition and mechanical properties of orthodontic aligners in vitro

BACKGROUND

The aim of the study was to investigate the effect of three aligner cleaners on the composition and mechanical properties of two types of orthodontic aligners.

MATERIALS AND METHODS

The cleaners tested were two alkaline peroxide solutions (Retainer Brite-RB; Retainer Cleaner-RC) and one peroxide-free (Steraligner-ST) and the aligners Clear Aligner (C, polyester) and Invisalign (I, polyester-urethane). The aligners were immersed in the cleaner solutions as instructed every day (15 min for RB, RC; 5 min for ST) for a two-week period. The acidity of the solutions was tested with a pH meter. The changes in the chemical composition of the aligners were studied by attenuated total-reflection Fourier transform infrared spectrometry (ATR-FTIR), while Instrumented Indentation Testing (IIT) was used for assessment of changes in Martens Hardness (HM), modulus (E_IT), elastic index (n_IT) and relaxation (R_IT).

RESULTS

RB and RC were weakly acidic (pH = 6.3), whereas ST was mildly acidic (pH = 4.8). The ATR-FTIR analysis demonstrated evidence of acidic hydrolysis of C in ST and I in RB. The IIT-derived properties of I were not affected by the cleaners. However, for C a significant change was found in HM (all cleaners), n_IT (all cleaners) and R_IT (RB, ST). Although the chemical changes support a hydrolytic material deterioration, the results of mechanical properties may interfere with the material residual stresses during fabrication.

CONCLUSIONS

Caution should be exerted in the selection of aligner cleaners. The mild acidic cleanser was more aggressive to the polyester, whereas an alkaline peroxide to the polyester-urethane aligner.

Ultrastructural analysis of the submandibular sialoliths: Raman spectroscopy and electron back-scatter studies

The aim of work was the epidemiological analysis of the occurrence of sialolithiasis of the submandibular gland in adults and the evaluation of the ultrastructure of salivary stones. The study sample consisted of 44 sialoliths. Analysis of the structure and chemical composition of sialoliths was performed using a Scanning Electron Microscope and Raman Spectroscopy. Comparing our results with the literature we can say that the epidemiology of sialolithiasis has not changed significantly over the past 50 years. A wide variety of sialoliths structure was observed. In 75% (33) cases a layered structure of salivary stones was observed, while in 25% (11) - homogeneous structure. The various distribution of organic and inorganic components was observed among all the analyzed sialoliths. Raman spectroscopy allows for preliminary analysis of the sialoliths structure with only a qualitative assessment of their composition, which significantly reduces the research value of this method. The presence of organic and inorganic compounds in the core and inner layers of the salivary glands stones confirms 2 basic theories of the formation of sialoliths: inflammation and deposition of the inorganic component as a result of disruption of saliva flow in the salivary glands.