Dental technology has developed materials for prosthetics that are very similar to natural teeth and offer a good balance between durability and esthetics; however, some of these materials are not ...very color-stable under the influence of external factors. Therefore, the aim of this study is to determine and compare the color change (∆E00) of different esthetic monolithic monochromatic CAD/CAM materials after they have been thermocycled and treated with staining solutions. The color parameters were determined using a spectrophotometer on a white and black background. Five CAD/CAM materials were used for this study—CAD/CAM nanoceramic (GC Cerasmart270), CAD/CAM lithium disilicate ceramic (IPS e.max CAD), CAD/CAM polymer (Telio CAD), CAD/CAM composite (Tetric CAD) and CAD/CAM polymer-infiltrated ceramic (Vita Enamic). The test specimens produced were divided into groups and were thermocycled in distilled water. They were then stored for four weeks at 37 °C in either distilled water as a control liquid, black tea, instant coffee or red wine. The aim is also to evaluate the color changes as a function of the exposure time of the staining solutions. The results obtained were analyzed statistically. All CAD/CAM materials tend to discolor to varying degrees. Among the factors contributing to discoloration, red wine proved to be the most significant influencing factor. The conclusion from the results is that the color change is influenced by the type of material, the staining solution, the sample thickness, the color background and the aging time.
Variations in the timing of emergence of primary teeth are under strong genetic control, but there is also a significant contribution from external factors. The aim of this study was to evaluate the ...influence of preterm birth, birth weight and length, and feeding practices during the first 6 months of life on the timing of emergence of the first primary tooth.
Data on pregnancy duration, birth weight and length, feeding practice, time of emergence and first emerged primary tooth were collected by electronic questionnaires. The study included 409 parents and 592 children of both genders. The sample was divided into two groups according to pregnancy duration (<37 weeks and ≥37 weeks), three groups according to feeding practice (exclusively breastfed, exclusively bottle fed, and a combination of breast feeding and bottle feeding), three groups by birth length (<50, 50–53, >53cm), and four groups by birth weight (<1500, 1500–2500, 2501–3500, >3500g). Data were analyzed considering chronological and postmenstrual age—which is the gestational age plus the infant's chronological age at the month of emergence of the first primary tooth.
The mean time of first primary tooth emergence was 7.55±2.67 months when chronological age was considered. The first emerged tooth in most cases was a lower incisor (82.33%). There was a statistically significant difference in the timing of the first tooth emergence between preterm and full-term groups when chronological age was considered (p<0.005). However, no difference was found when age was adjusted. The age of emergence of the first tooth differed significantly when feeding, weight, and length groups (p<0. 05) were taken into account.
In conclusion, the study indicates that shortened gestational age and very low birth weight are predictors for later ages of emergence of the first primary tooth.
The purpose of the study was to find differences in the parameters of the response to the blink reflex (BR) between patients with idiopathic trigeminal neuralgia (TN) and health volunteers. A ...prospective cohort study was conducted over 2 years. The TN-subgroup included 15 patients (mean age / SD 62.3 ± 10.7 years). Pain-free and healthy volunteers as a HV-subgroup (mean age / SD: 30.8 ± 8.1 years) were recruited from asymptomatic students of dental medicine. Diagnostic parameters were determined by measuring latency to the onset of the BR components from electric stimulation. The following branches of the trigeminal nerve were affected: maxillary branch only (26.7%), mandibular branch only (20%), combined: ophthalmic branch with maxillary branch (6.7%), and ophthalmic branch with mandibular branch (6.7%) respectively, combined maxillary and mandibular branch (26.7%) and affected all three branches (13.4%). The latencies of the BR, left and right side together, between subgroups were significantly higher for values R1 (homolateral early response), R2 (homolateral late response), R2c latency (contralaterally expressed response) in the TN-subgroup (p < 0.05). On the basis of the presence of R1c and R3 latencies and upon considering the abnormal findings of the BR, no statistically significant differences were found between the examined subgroups (p > 0.05). Blink-reflex parameters (R1, R2 and R2c) were significantly abnormal comparing TN-patients with healthy volunteers. The R3 component of the BR was related to noxious stimuli, likewise by innocuous stimuli.
The study aimed to determine the relationship between the mandibular asymmetry index according to Kjellberg between patients with painful unilateral anterior disc displacement (DD) and asymptomatic ...volunteers without disc displacement. Vertical measurements were performed on a panoramic single-image radiograph, and the disc status was confirmed by magnetic resonance imaging (MRI).
Two groups of subjects were retrospectively selected, 40 patients (the overall mean age was 35.5 years; 75% female) with temporomandibular disorder symptoms confirmed by RDC/TMD axis I and manual functional analysis. Unilateral DD was determined by MRI. A comparative group of asymptomatic volunteers (20 dental students with a mean age of 23.4 years; 72% female) had the physiological position of the disc determined by MRI. The vertical asymmetry of the condyle was determined by the method of Kjellberg et al. The symmetry of the gonial angle of the mandible was also measured.
A comparison of the mean of the asymmetry index between patients (average 90.89±7.08%) and asymptomatic volunteers (mean 95.86±4.44%) showed a statistically significant difference (p=0.0029). There was no difference (p=0.088) in gonial angle symmetry between the patients (mean 96.48±2.96°) and the asymptomatic volunteers (mean 97.52±2.31°). The distribution of the presence of individual DD diagnoses (partial and total displacement with reduction, displacement without reduction) in patients diagnosed with asymmetry of the mandible was without statistical significance (p>0.05).
This study actually points to the asymmetry of the mandible as a potential morphological risk of anterior DD.
Temporomandibular disorders (TMD) have been associated with altered salivary oxidative status, but the relation with pain source and pain severity isn't clarified. With the aim to assess their ...interaction with TMD, we compared levels of selected salivary oxidative stress (OS) markers (glutathione peroxidase, superoxide dismutase, total antioxidant capacity (TAC), uric acid, 8-hydroxydeoxyguanosine, malondialdehyde) and salivary cortisol (SC) as a stress indicator, between 20 TMD patients and 15 healthy control subjects. In order to record differences relating to pain source and severity, patients were respectively classified according to specific diagnoses (myofascial pain or disc displacement (DD)), and pain intensity (high or low). TAC was significantly higher in TMD patients than in controls (morning
= 0.015; afternoon
= 0.005). Significant differences were also observed when TAC levels between high-intensity pain patients and controls were compared, as well as between DD patients and controls. In logistic regression analysis, higher levels of TAC were related to DD (morning OR: 1.66, 95%CI: 1.05-2.64,
= 0.029; afternoon OR: 2.10, 95%CI: 1.11-3.98,
= 0.021) and to high-intensity pain (morning OR: 1.81, 95%CI: 1.04-3.15,
= 0.037; afternoon OR: 1.79, 95%CI: 1.02-3.14,
= 0.043). We also found that morning SC was positively correlated with antioxidant parameters in TMD patients. Our data suggest compensatory mechanism as response to higher level of stress. This stress could be extrinsic and lead toward TMD, or intrinsic, emerging from established TMD, or could be both. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers in TMD patients.
- The purpose was to evaluate dental caries experience in different male subpopulations of Croatian Army recruits and dental students, and subsequently, smoking habits related to the level of ...education and place of residence. Croatian army recruits (n=248; mean age 20.2) and male dental students (n=56; mean age 21.5) were evaluated according to DMFT and FST indices, divided according to age and place of residence, and interviewed about their dietary habits and smoking of tobacco. In the subpopulation of recruits, the median value of DMFT was 6 and of FST index 25. A statistically significant difference was recorded between DT and FST index (p<0.05) according to dietary role of carbohydrates reflected in caries development. The number of recruits with finished elementary school coming from a rural area who smoked (in total 57.66% of smokers) was significantly larger (p=0.0041). In dental students, the median value of DMFT was 5, with statistical significance in comparison with recruits (p=0.03). There was a difference in FST index (median 28) (p<0.0001). Students were mostly nonsmokers (71.43%) and had urban residence (p<0.0001). FST index was a more specific indicator in the socioeconomically heterogeneous sample of recruits (more subjects coming from rural areas and with a lower level of education) than in the sample of dental students (more subjects coming from urban areas).
The aim of the study was to analyze zygomatic air cell defect (ZACD) incidence using magnetic resonance imaging (MRI) and validity of panoramic radiograph as a comparative method of ZACD diagnostics. ...The connection between ZACD incidence, age, left/right temporomandibular joint (TMJ) and comorbidity with diagnosis of TMJ disorder was analyzed. Panoramic radiographs and MRIs of 140 TMJs of 70 consecutive patients with previously confirmed TMJ diagnosis were compared in the study. A grading system (4-point scale from '0' for absence to '3' for most extended pneumatization) was used to determine low signal on MRIs as pneumatization of temporal bone. ZACD was diagnosed in 22 joints of 15 patients (incidence, 20.4%), with seven patients having bilateral appearance. In the joints of nine patients, ZACD was identified as extensive accord-ing to the grading scale. The validity of ZACD findings on panoramic radiographs compared with MRI findings yielded 0.45 sensitivity and 0.98 specificity. There was no relation (p>0.05) between comorbidity of ZACD and TMJ disorder, either by age or side of the body. More prevalent ZACD in our MRI analysis than in other researches based on panoramic radiographs could be explained by the expected superimposed osseous structures in the area of articular eminence.
The aim of this study was to evaluate Croatian undergraduate students' knowledge based on what they learned in the recent course, as well as the students' own judgment and opinions about geriatric ...dentistry education concerning temporomandibular disorders (TMDs) of the elderly. The study was carried out by means of a questionnaire administered in the last study year to students of the School of Dental Medicine, University of Zagreb and students of the Department of Dental Medicine at the School of Medicine, University of Rijeka. Th e questionnaire included questions about relevant specific knowledge on TMD, and statements related to their own opinion about geriatric dentistry education received during the study. Regarding students' knowledge related to TMDs, students from Rijeka gave more positive answers (p=0.012). Students from Rijeka gave more positive answers regarding physical therapy for treatment of TMD (p=0.004) and disc displacement and osteoarthritis as the most common disorders of the temporomandibular joint (p=0.031). Students from Zagreb were more unsatisfi ed with the skills in the field of geriatric dentistry (disagreed 57.45%) than students from Rijeka (45.83% had neutral standpoint and 37.50% agreed) (p=0.005). The level of the participants' knowledge pointed to the need of improving undergraduate dental teaching about the specific geriatric education, including knowledge about TMD.
doi: 10.1111/j.1741‐2358.2011.00552.x
Study of temporomandibular joint disorder in older patients by magnetic resonance imaging (MRI)
Objectives: To compare characteristics in older patients in a ...sample of the general population of those with temporomandibular joint disorder (TMJD).
Materials and methods: A prospective study was carried out between 2001 and 2008 in patients with TMJD. The whole sample consisted of 141 patients divided in two groups: 31 patients aged over 60 (median age 67.9, ranging from 60 to 82) and the remaining 110 patients (median age 36.3, ranging from 12 to 59) who were seeking treatment. Clinical diagnostics was confirmed by MRI. Pain intensity was rated on a visual analogue scale (VAS 0‐10).
Results: There was no statistical difference between average pain in older patients (6.2) and patients aged up to 59 (5.7) evaluated by VAS. There was a statistically significant difference (p = 0.002) in pain duration: older patients reported shorter duration of experienced pain (7.8 months) than patients aged up to 59 (12.2 months).
Conclusion: In this study, it was found that 22% were older patients with TMJD. A higher level of anxiety was shown in both patients’ groups, regardless of shorter pain experience in the older patients.
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