Evaluation of method parameters for sound undecalcified dental enamel proteomics using liquid chromatography-mass spectrometry.

OBJECTIVE: This study aims to validate a methodology for analyzing undecalcified, sound dental enamel proteomics using Liquid Chromatography-Mass Spectrometry (LC-MS). The study evaluates various parameters, including the impact of dental root coverage on protein contamination, the efficacy of protease inhibitors during enamel sample preparation, repeatability of LC-MS measurements on dental enamel, and statistical analysis. The study also assesses the effectiveness of combined trypsin and semi-trypsin searches in Mascot for obtaining additional protein identification data. DESIGN: Sound dental enamel was removed using a wet grinding technique, then digested with trypsin and labeled with TMT prior to LC-MS analysis. The resulting proteomes were matched against the Homo sapiens Swissprot Database, with searches in Mascot performed using both trypsin and semitrypsin. Statistical methods were employed to analyze the data. RESULTS: The study found that covering dental roots with composite during dental enamel microdissection is advisable, while using protease inhibition during microdissection may not be fully supported. The proteomic analyses demonstrated statistical repeatability and reliability, with consistent and reproducible proteomic data obtained from healthy dental enamel. Furthermore, employing both trypsin and semitrypsin searches in Mascot provided additional proteomic information. CONCLUSIONS: Overall, this study validates a methodology for analyzing undecalcified, sound dental enamel proteomics using LC-MS, and provides insights into various factors that can affect the quality and reliability of proteomic data. These findings have implications for future studies pursuant to understanding the proteomic mechanisms underlying dental enamel formation and other associated processes.

A pilot study comparing optical coherence tomography, radiography, clinical photography, and polarisation microscopy for studies of hypomineralisation disturbances in enamel.

Aim: To investigate the use of optical coherence tomography (OCT) as a tool to assess general and localised hypomineralisation defects in the enamel. Design and Materials: Ten extracted permanent teeth (four teeth with localised hypomineralisation, four teeth with general hypomineralisation, and two healthy controls) were used in this study. In addition, four participants who underwent OCT served as living controls for the extracted teeth. Methods: The OCT results were compared with clinical photographs, digital radiographs, and polarising microscopy images of tooth sections (considered the gold standard) to determine the method with the most accurate information regarding the extent of enamel disturbances: 1) visibility of enamel disturbance (visible yes/no); if yes, 2) extent of the disturbance in the enamel; and 3) determination of the plausible involvement of the underlying dentin. Results: OCT was more accurate than digital radiography and visual assessment. OCT could provide information about the extent of localised hypomineralised disturbances in the enamel that was comparable to that with polarisation microscopy of the tooth sections. Conclusion: Within the limitations of this pilot study, it can be concluded that OCT is suitable for investigating and evaluating localised hypomineralisation disturbances; however, it is less useful in cases with generalised hypomineralisation of the enamel. In addition, OCT complements radiographic examination of enamel; however, more studies are necessary to elucidate the full extent of the use of OCT in case of hypomineralisation.

Apical root resorptions in girls with Turner syndrome: a controlled longitudinal study.

OBJECTIVES: To study, longitudinally, the development of apical root resorptions (ARRs) in Turner syndrome (TS) and to correlate these to the karyotype and orthodontic treatment. MATERIALS AND METHODS: Thirty girls with TS participated in the study, mean age 10.8 years (6.6-23.4) at the first registration (T1), and 14.3 years (9.2-25.2) at the second registration (T2). Forty girls without TS, orthodontically untreated, served as controls. ARR was diagnosed in panoramic radiographs, and root/crown ratios of the lower permanent first molar were measured at T1 and T2 with a mean follow-up period of 42 (11-89) months. RESULTS: During the follow-up period, ARR was seen in 40% of all TS patients and in 2.5% in the control group. The majority displayed ARR on the distal root of the mandibular first permanent molars (30%). ARR at T2 was seen in 56% of 45,X and isochromosome karyotype and 21% of every other TS karyotype patients. AAR was seen in 5 out of 12 TS patients with orthodontic treatment. No statistically significant differences in root/crown ratios between T1 and T2 were found. LIMITATIONS: The number of patients studied is limited, thus possible differences might be disguised for this reason. Spatial projection errors in panoramic radiograph recordings might have influenced measurement, resulting in an underestimation of ARR. CONCLUSIONS: There is a higher risk for ARR in girls with TS and probably the risk is therefore probably also higher during orthodontic treatment. Thus, if treated, frequent radiographic follow-ups should be taken during the treatment. PROTOCOL: The protocol was not published before trial commencement.

Integration of Dental Implants in Conjunction with EDTA-Conditioned Dentin Grafts: An Experimental Study.

This study was undertaken to investigate the integration of titanium micro-implants installed in conjunction with previously dentin-grafted areas and to study the morphological appearance, mineral content, and healing pattern of xenogenic EDTA-conditioned dentin blocks and granules grafted to cavities in the tibial bone of rabbits. Demineralized and non-demineralized dentin blocks and granules from human premolars were implanted into cavities prepared on the lateral aspects of the tibias of rabbits. After a healing period of six months, micro-implants were installed at each surgical site. Histological examinations were carried out after 24 weeks. Characterization of the EDTA-conditioned dentin blocks was performed by means of light microscopy, dental X-rays, scanning electron microscopy, and energy dispersive X-ray analysis (EDX). No implants were found to be integrated in direct contact with the dentin particles or blocks. On the EDTA-conditioned dentin surface, the organic marker elements C and N dominated, as revealed by EDX. The hydroxyapatite constituents Ca and P were almost absent on the dentin surface. No statistically significant difference was observed between the EDTA-conditioned and non-demineralized dentin, as revealed by BIC and BA. The bone-inductive capacity of the dentin material seemed limited, although demineralization by means of EDTA indicated higher BIC and BA values in conjunction with the installed implants in the area. A 12 h EDTA treatment did not fully decalcify the grafts, as revealed by X-ray analysis.

How sandblasting on lingual surfaces can be carried out with minimum enamel damage: An in vitro study on human teeth.

OBJECTIVE: The aim was to assess the extent of enamel damage sandblasting might cause and to identify a combination of sandblasting durations and MicroEtcher nozzle-tooth surface distance (NTD) resulting in the least enamel damage. MATERIALS AND METHODS: Lingual surfaces of 30 human teeth were sandblasted with 2 different distances: 1, 2mm and 3 different durations: 1, 2, 3s and photographed using a light microscope. The cavity depth and diameter of the sandblasted teeth were measured on the light microscope's pictures. A pilot study was performed to minimize possible combinations of sandblasting durations and distances. To validate the measurement method, sandblasted teeth were ground cut for comparison. Inter-examiner reliability was assessed with Bland-Altman analysis. Mann-Whitney U-test was used to detect cavity and diameter changes for every sandblasting duration and NTD combination. RESULTS: From the pilot study sandblasting durations 1,2 and 3s and NTD<2mm were chosen. The cavity diameter of the sandblasted area did not change with increased sandblasting duration nor NTD (P>0.05). The cavity depth of the sandblasted area increased statistically with an increased sandblasting duration (P<0.05) but did not increase with an increase NTD (P>0.05). The 95% limits of inter-examiner agreement were narrow. CONCLUSION: All distance and duration combinations tested caused enamel damage. Sandblasting duration had greater impact on the cavity depth than the NTD. The blasting duration should, therefore, not exceed 2s and the NTD should be held at maximum 2mm to minimize the risk of unintentional spread.

Interproximal grinding (disking) of caries in primary molars, attitudes and the extent utilized in a Swedish County.

OBJECTIVE: To assess the occurrence of interproximal grinding as a caries therapy in primary molars, to what degree grinding replaced conventional restorative caries therapy, to what extent anaesthesia was used while grinding and to assess open comments about attitudes about grinding. MATERIALS AND METHODS: A questionnaire was sent to 108 public dental service clinics with questions concerning the use of grinding as a therapy and alternative to restorative treatment, the use of anaesthesia prior to conventional caries therapy and grinding, respectively. In addition, a content analysis of open comments about grinding was performed. RESULTS: Grinding had been performed in 96% of the clinics. Two-thirds of the dentists used grinding as an alternative to conventional restorative treatment at some point. Most dentists used anaesthesia prior to restorative therapy. Prior to grinding, the frequency of anaesthesia was lower (median 5.0) than for conventional restorative therapy (median 8.7) (p < .001). The open comment analysis revealed complex reasons for the use of grinding. CONCLUSIONS: Grinding has been widely practiced in parts of Sweden, is presently a technique employed by a multitude of dentists, and that anaesthesia is used less frequently prior to grinding, in comparison to conventional restorative therapy. Dentist considered grinding as a treatment option in specific situations.

Caries risk profiles in orthodontic patients: A 4-year follow-up study using the Cariogram model in governmental vs. private clinics.

OBJECTIVES: To (1) analyze caries-related factors and (2) evaluate caries risk using the Cariogram model for governmental and private orthodontic patients at de-bonding and 4 years after de-bonding. MATERIALS AND METHODS: Forty orthodontic patients with mean age of 26.4 years were recruited from a governmental (G) group (n = 20) and private (P) group (n = 20) and were examined at de-bonding (T1) and 4 years after de-bonding (T2). The examination included a questionnaire, plaque scoring, caries examination, bitewing radiographs, and assessment of salivary secretion rate, buffering capacity and cariogenic microorganisms. The data were entered into the Cariogram program to illustrate the caries risk profiles. RESULTS: The chance to avoid new cavities was higher in P-group compared to G-group at T1 (58% and 31%, respectively) (P < 0.01) and T2 (77% and 52%, respectively) (P < 0.001). Plaque index was significantly higher in G-group, and fluoride was used significantly more in P-group at T1 and T2 (P < 0.05). The chance to avoid new cavities was higher at T2 compared to T1 (64% and 44%, respectively) (P < 0.001). Saliva secretion rate and buffer capacity were significantly increased, and the plaque index was significantly decreased at T2 compared to T1 (P < 0.01). CONCLUSION: According to the Cariogram, orthodontic patients were less likely to avoid new cavities at de-bonding and 4 years after de-bonding in government clinics compared to private clinics, and the caries risk significantly decreased 4 years after orthodontic treatment for all patients, regardless of the location of treatment.

A comparative study of cone beam computed tomography and conventional radiography in diagnosing the extent of root resorptions.

BACKGROUND: Root resorptions are assessed and diagnosed using different radiographical techniques. A comparison of the ability to assess resorptions on two-dimensional (2D) and three-dimensional (3D) radiographs is, hitherto, lacking. The aims of this study were to evaluate the accuracy of 2D (periapical radiographs, PA and panoramic radiograph, PAN) and 3D (cone beam computed tomography, CBCT) radiographic techniques in measuring slanted root resorptions compared to the true resorptions, a histological gold standard, in addition to a comparison of all the radiographic techniques to each other. METHODS: Radiographs (CBCT, PA, and PAN), in addition to histological sections, of extracted deciduous canines from thirty-four patients were analyzed. Linear measurements of the most and least resorbed side of the root, i.e., "slanted" resorptions, were measured using an analyzing software (Facad ®). For classification of slanted root resorptions, a modified Malmgren index was used. RESULTS: PAN underestimated the root length on both the least and most resorbed side. Small resorptions, i.e., low modified Malmgren scores, were more difficult to record and were only assessed accurately using CBCT. The root resorption scores were underestimated using PA and PAN. In assessment of linear measures, PAN differed significantly from both CBCT and PA. CONCLUSIONS: CBCT is the most accurate technique when measuring and scoring slanted root resorptions.

Diagnosing the severity of buccal caries lesions in orthodontic patients at de-bonding using digital photographs.

OBJECTIVE: The aims of this study were (1) to evaluate the severity of buccal caries lesions according to the International Caries Detection and Assessment System (ICDAS) criteria via scoring buccal caries lesions on digital photographs at the time of de-bonding and (2) to compare this method with clinical examination. MATERIALS AND METHODS: In total, 89 patients treated with upper and lower fixed appliances were clinically examined immediately after de-bonding by the first author and buccal caries were scored according to the ICDAS-II. Close-up digital photographs were taken of 245 teeth with different buccal caries lesion scores according to the ICDAS-II. Thirteen postgraduate orthodontics students independently scored the buccal caries lesions in the digital photographs using the modified clinical criteria (ICDAS-II). Intra- and inter-examiner reliabilities were evaluated by calculating the weighted kappa. To evaluate the validity of diagnosing the severity of buccal caries lesions using digital photographs compared to clinical examination, Spearman's correlation coefficient was calculated. RESULTS: Intra-examiner reliability and the reliability between each examiner and the clinical examination showed moderate-to-excellent agreement, with kappa values of 0.52-0.83. Scoring buccal caries lesions via clinical examinations and scoring via photographs were well correlated according to the modified ICDAS-II criteria (Spearman's correlation coefficient, 0.76). CONCLUSIONS: Thus, scoring buccal caries lesions on digital photographs according to ICDAS-II criteria is a reliable and valid method for assessing the severity of buccal caries lesions.

Diagnosing the severity of buccal caries lesions in governmental and private orthodontic patients at debonding, using the ICDAS-II and the DIAGNOdent Pen.

OBJECTIVES: To clinically evaluate the prevalence of buccal caries and white spot lesions (WSLs) at debonding in governmental and private orthodontic patients, using the International Caries Detection and Assessment System (ICDAS-II) and the DIAGNOdent Pen, and to study the correlation between the two methods. MATERIALS AND METHODS: A cross-sectional study was carried out on the nonextracted premolars and anterior teeth of 89 orthodontic patients. They were recruited into two groups based on the treatment center they attended: governmental group (G; n=45) and private group (P; n=44). Immediately after debonding, the examination of buccal caries and WSLs on premolars and anterior teeth was carried out using the ICDAS-II and the DIAGNOdent Pen. Cross-tabulation was applied to study the correlation between the ICDAS-II index and the DIAGNOdent Pen by calculating the Spearman correlation coefficient. RESULTS: The G group showed a significantly higher (P<.0001) prevalence of WSLs and/or buccal caries compared to that of the P group based on evaluation by the two methods. Based on ICDAS-II, 43% of the patients in the P group and 9% in the G group were free from any WSLs. In the G group, 22% of the patients had ≥16 LESIONS, whereas there were none for the P group. The Spearman correlation coefficient between the two methods was .71. CONCLUSIONS: The prevalence of caries and/or WSLs at debonding was significantly higher in the G group compared to the P group. The clinical index (ICDAS-II) showed a good correlation with the DIAGNOdent Pen.

Altered inorganic composition of dental enamel and dentin in primary teeth from girls with Turner syndrome.

In Turner syndrome (TS) one X-chromosome is missing or defective. The amelogenin gene, located on the X-chromosome, plays a key role during the formation of dental enamel. The aim of this study was to find support for the hypothesis that impaired expression of the X-chromosome influences mineral incorporation during amelogenesis and, indirectly, during dentinogenesis. Primary tooth enamel and dentin from girls with TS were analysed and compared with the enamel and dentin of primary teeth from healthy girls. Qualitative and quantitative changes in the composition of TS enamel were found, in addition to morphological differences. Higher frequencies of subsurface lesions and rod-free zones were seen in TS enamel using polarized light microscopy. Similarly, scanning electron microscopy showed that the enamel rods from TS teeth were of atypical sizes and directions. Using X-ray microanalysis, high levels of calcium and phosphorus, and low levels of carbon, were found in both TS enamel and dentin. Using microradiography, a lower degree of mineralization was found in TS enamel. Rule induction analysis was performed to identify characteristic element patterns for TS. Low values of carbon were the most critical attributes for the outcome TS. The conclusion was that impaired expression of the X-chromosome has an impact on dental hard tissue formation.

Elemental composition of normal primary tooth enamel analyzed with XRMA and SIMS.

There is an interest to analyze the chemical composition of enamel in teeth from patients with different developmental disorders or syndromes and evaluate possible differences compared to normal composition. For this purpose, it is essential to have reference material. The aim of this study was to, by means of X-ray micro analyses (XRMA) and secondary ion mass spectrometry (SIMS), present concentration gradients for C, O, P and Ca and F, Na, Mg, Cl, K and Sr in normal enamel of primary teeth from healthy individuals. 36 exfoliated primary teeth from 36 healthy children were collected, sectioned, and analyzed in the enamel and dentin with X-ray micro analyses for the content of C, O, P and Ca and F, Na MgCl, K and Sr. This study has supplied reference data for C, O, P and Ca in enamel in primary teeth from healthy subjects. No statistically significant differences in the elemental composition were found between incisors and molars.The ratio Ca/P is in concordance with other studies. Some elements have shown statistically significant differences between different levels of measurement. These results may be used as reference values for research on the chemical composition of enamel and dentin in primary teeth from patients with different conditions and/or syndromes.

Influence of pH and time on organic substance release from a model dental composite: a fluorescence spectrophotometry and gas chromatography/mass spectrometry analysis.

In this study we assessed the influence of pH and time on the degradation and elution of organic substances from the composite resin material, Z-100. To accomplish this, fluorescence spectrophotometry was evaluated as an appropriate technique for the identification of six organic substances (methacrylic acid, methyl methacrylate, hydroquinone, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate and 4,4'-isopropylidenediphenol) that were eluted from resin composite material stored for 24 h or 6 months at pH 4.0, 6.0 or 8.0. In addition, complementary analyses (solid-phase microextraction/gas chromatography/mass spectrometry) were carried out to identify and quantify the substances. The main substances leached from the resin composite were methacrylic acid, triethylene glycol dimethacrylate and hydroquinone. It was concluded that fluorescence spectrophotometry seems to be a suitable, non-destructive technique for the qualitative analysis of eluted organic components. Critical combinations of time and pH allowed the elution of several organic substances, predominantly methacrylic acid, triethylene glycol dimethacrylate and hydroquinone, from the model resin composite, Z-100.