Coverage error of three resin composite systems to vital unrestored maxillary anterior teeth

OBJECTIVE

Define the color of anterior teeth of a selected population and correlate it (by using coverage error [CE] and the frequency of best match) with the final color of all possible enamel-dentine combinations of three different resin composite systems.

MATERIALS AND METHODS

Color of 636 vital unrestored anterior teeth (central incisors, lateral incisors and canines; n = 212) and disk specimens (12 mm diameter, varying thickness) corresponding to enamel-dentin combinations of all available enamel (0.5 mm and 1.0 mm thickness) and dentin shades (3.0 mm thickness) of Essentia, Enamel Plus HRi and IPS Empress Direct composite systems was measured using a clinical dental spectrophotometer (Spectroshade Micro). CE and frequency of best match for all composite systems were calculated for the measured in-vivo teeth color space.

RESULTS

Natural in-vivo teeth exhibit higher lightness when compared to enamel-dentin composite combinations, independently of the enamel thickness used. The best (lowest) CE was found for IPS Empress, while the highest values were found for Enamel Plus Hri independently of tooth type and enamel thickness (p < 0.001). The use of 0.5 mm instead of 1.0 mm enamel thickness within enamel-dentin composite combinations resulted in a lower CE for in-vivo tooth color (p < 0.001).

CONCLUSIONS

The color space defined by all possible enamel-dentin combinations of the studied resin composite systems does not fully match the color range of anterior teeth. All composite systems examined lack combinations with lightness values as high as the population's. IPS Empress Direct composite system represented better the in-vivo teeth color.

CLINICAL SIGNIFICANCE

The use of 0.5 mm enamel shade thickness is suggested when building layered restorations, as it provided better color coverage than using 1.0 mm thickness.

Association of Number of Teeth with ADL/IADL in Korean Middle-Aged and Older Adults: An Analysis of the 7th Korean Longitudinal Study of Aging

We determined the association between the number of natural and implant teeth with activities of daily living (ADL) and instrumental ADL (IADL) levels in middle-aged and older adults aged ≥ 55 years. We included 6,925 participants, who underwent a computer-assisted personal interview in the 7th Korean Longitudinal Study of Aging. After controlling for general characteristics, the associations between the number of natural and implant teeth with ADL and IADL levels were examined using multiple regression analysis. The participants had 21.2 natural teeth and 1.08 implant teeth on average. The ADL and IADL levels were 0.61 and 1.56, 0.40 and 1.16, and 1.10 and 0.31 in participants with ≤ 9, 10-19, and ≥ 20 teeth, respectively. There was no significant association between ADL and the number of natural and implant teeth (p > 0.05). However, a one-unit increase in IADL score was associated with a reduced number of natural (β = -0.031, p < 0.001) and implant (β = -0.194, p = 0.006) teeth. Difficulties regarding IADL were associated with fewer natural and implant teeth, suggesting that maintaining and managing the number of teeth is critical to promoting the health of middle-aged and older adults.

Are there any color match and color correlation between maxillary anterior teeth?

OBJECTIVE

To evaluate the color match and color correlation between maxillary anterior teeth.

MATERIALS AND METHODS

CIELab values of 1182 intact maxillary anterior teeth in 197 human specimens were measured through spectrophotometry. ∆E₀₀ color differences between similar regions of the same and different type teeth were calculated and compared with perceptibility and acceptability thresholds using 1-sample t test to evaluate color matches. Regression analyses assessed linear relationships between the color coordinates of similar regions of different type teeth. Percentages of different modes of the color match between the same specimen's teeth (2-tooth/3-tooth color match or color mismatch) were determined.

RESULTS

Mean ∆E₀₀ values for the same type teeth were less than 1.8 (p = 1). Mean ∆E₀₀ values for different type teeth were mostly greater than 1.8 (p < 0.001), except for central and lateral teeth in middle (p = 0.29) and incisal (p = 0.75) regions and for lateral and canine teeth in cervical regions (p = 0.33). The 2-tooth color match showed the highest percentage (>50%).

CONCLUSIONS

The same type teeth indicated color matches. Central and lateral teeth showed color matches in middle and incisal regions, while lateral and canine teeth disclosed color matches in cervical regions. The corresponding color coordinates of mismatched regions were linearly correlated.

CLINICAL SIGNIFICANCE

In order to predict and determine the shade of maxillary anterior teeth and create natural colors for corresponding restorations, some tooth color relationships and equations are presented in this study.

Frailty and Associated Factors among Chinese Centenarians

OBJECTIVES

The study aimed to apply the frailty index (FI) to assess frailty status among Chinese centenarians and analyse its associated factors.

DESIGN

The study was a cross-sectional study.

SETTING AND PARTICIPANTS

The study included 1043 centenarians (742 females and 301 males) aged ≥100 years from the 2018 wave of the China Longitudinal Healthy Longevity Survey.

MEASUREMENTS

All participants were assessed for frailty by the FI. Basic characteristics, including age, height, weight, calf circumference, waist circumference, hip circumference, sex, years of education, financial status, exercise, fall status, coresidence, smoking, alcohol consumption, number of natural teeth, denture use, toothache, and tooth brushing, were collected. Multivariate logistic regression was used to analyse the associations between risk factors and frailty.

RESULTS

The average age of the participants was 102.06±2.55 years (range: 100-117 years). The FI ranged between 0.00 and 0.63. The mean FI for all participants was 0.27±0.13 (median 0.25; interquartile range 0.20-0.35). Participants were divided into quartiles. The number of natural teeth and denture use, coresidence, sex, exercise, and financial status showed significant associations with frailty classes (all P<0.05). Multivariate logistic regression analysis indicated that having ≤20 natural teeth without dentures (OR, 95% CI= 1.89(0.004-1.246), P<0.05), having ≤20 natural teeth with dentures (OR, 95% CI=2.21(0.158,1.432), P=0.015), living alone or in an institution (OR, 95% CI=1.68(0.182-0.849), P=0.002), lacking exercise (OR, 95% CI=2.54(0.616-1.246), P<0.001), having insufficient financial resources (OR, 95% CI=2.9(0.664-1.468), P<0.001), and being female (OR, 95% CI=1.47(0.137,0.634), P=0.002) were independent risk factors for frailty.

CONCLUSION

Chinese centenarian women are frailer than men. Having fewer natural teeth, living alone or in an institution, lacking exercise, and having insufficient financial resources were the factors associated with frailty among Chinese centenarians. Family conditions and healthy lifestyles may be important for frailty status in centenarians.

Effect of Opposite Tooth Condition on Marginal Bone Loss around Submerged Dental Implants: A Retrospective Study with a 3-Year Follow-Up

Background: The objective of this study was to evaluate the effects of opposite tooth conditions on change in marginal bone level (MBL) around submerged dental implants. Materials and methods: The study included healthy patients with one or two implants. Structures opposite implants were either natural teeth (NT) or fixed restorations (FRs). MBLs were measured on digital periapical radiographs at the mesial and distal aspects of each implant. Results: Sixty implants were inserted by the 3-year follow-up. Mean MBLs for NT were 0.21 ± 0.33 mm before prosthetic loading and 0.30 ± 0.41 mm 3 years later (p = 0.001). Mean MBLs with FRs were 0.36 ± 0.45 mm before loading and 0.53 ± 0.50 mm 3 years later (p < 0.001). Changes in mean MBL from the 6-month follow-up to the 1- and 3-year follow-ups were statistically significant (p < 0.01) for implants opposite NT. However, changes in mean MBL from the 6-month follow-up to the 1-year (p = 0.161) and 3-year follow-ups (p = 1.000) were not significant for implants opposite FRs. Between baseline and the 3-year follow-up, MBL change was relatively small and did not differ regarding NT and FRs. Conclusion: Bone loss was greater if submerged dental implants were opposed by FRs. MBLs around submerged implants continued to change after 3 years if NT opposed implants.

A State-of-the-Art Review on the Wear of the Occlusal Surfaces of Natural Teeth and Prosthetic Crowns

This review focuses on the wear mechanisms of natural and restorative dental materials, presenting a comprehensive description and analysis of the works published in the last two decades on the wear at the interface of occlusal surfaces. Different groups of tribological pairs were considered: tooth-tooth, tooth-restorative material (tooth-ceramic, tooth-resin-based-materials, and tooth-metal), and restorative-restorative materials. The lack of standardization of the wear tests impairs the direct comparison of the obtained results. However, it was possible to infer about the main wear mechanisms observed on the different classes of dental materials. Concerning ceramics, their toughness and surface finishing determines the wear of antagonist tooth. Abrasion revealed to be the main wear mechanisms at occlusal interface. In the case of resin-based composites, the cohesion of the organic matrix and the nature, shape, and amount of filler particles greatly influences the dental wear. The protruding and detachment of the filler particles are the main causes of abrasion of antagonist enamel. Metallic materials induce lower wear on antagonist enamel than the other classes of materials, because of their low hardness and high ductility. Most of the studies revealed plastic deformation and adhesive wear as the main wear mechanisms. Overall, more research in this area is needed for a better understanding of the mechanisms involved at the occlusal surfaces wear. This would be essential for the development of more suitable restoration materials.

Effects of Khat on Surface Roughness and Color of Feldspathic and Zirconia Porcelain Materials under Simulated Oral Cavity Conditions

Background and Objectives: Khat chewing is considered as a daily habit that is practiced by more than five million people globally. The effect of khat chewing on the surface roughness and the color stability of natural teeth and the material used in the fabrication of dental prosthesis remains unknown. This study was conducted to explore and compare the effect of khat homogenate (KH) on the surface roughness (Ra) and the average color changes (ΔE*) amongst natural teeth and selected shades from different porcelain types, namely, feldspathic metal ceramic (MC) VM13, computer-aided design/computer assisted manufacture (CAD/CAM) feldspathic (Vitablocs Mark II), and multilayer zirconia (Ceramill Zolid PS) porcelains. Materials and Methods: Seventy samples were prepared from natural teeth, feldspathic MC, CAD/CAM Vitablocs Mark II, and zirconia porcelain. The Ra values were measured using a profilometer and expressed in micrometers, whereas the ΔE* values were measured using VITA Easyshade^® V spectrophotometer for all samples before and after frequent immersion and thermocycling in KH for 30 days. The surface topography was used to assess the materials surfaces (glazed or polished) after KH immersion by using a white light interferometry machine. Results: Results revealed that the Ra and the ΔE* values of the different types of tested porcelain were influenced by KH. The order of surface roughness values was glazed or polished MC > polished Zircon > polished Vitablocs Mark II > natural teeth. The lowest ΔE* values were recorded for glazed Vitablocs Mark II and MC, and the values could be arranged as polished zircon > natural teeth > glazed zircon > polished MC > polished Vitablocs Mark II. P values were significantly varied (<0.001) among all the tested groups, except the zircon group (>0.05) for both Ra and ΔE*. Conclusions: KH significantly affected both surface parameter and color of glazed or polished porcelain materials and natural teeth.

Tooth Loss-associated Cognitive Impairment in the Elderly: A Community-based Study in Japan

Objective Dementia is a major cause of disruption for a healthy life expectancy in Japan. It has been suggested that the number of teeth is a modifiable risk factor for cognitive impairment and dementia. We therefore examined the possible association between the cognitive function and the number of natural and artificial teeth in community-dwelling Japanese elderly individuals. Methods Among the participants in our prospective, community-based study, 210 elderly individuals (103 men and 107 women; 78.1±4.9 years; mean age±standard deviation) underwent both dental examinations and a Mini-Mental State Examination (MMSE), as well as various medical checkups, in 2016 and 2017. Results The number of natural teeth was significantly associated with an individual's MMSE score. The percentage of cognitively normal subjects (MMSE scores: 27-30) decreased significantly with a decrease in the number of natural teeth. Among the MMSE items, the calculation ability was significantly and independently associated with the number of natural teeth. Regression was calculated as the predicted score of MMSE =21+0.3× (years of schooling) +0.1× (number of natural teeth). Among individuals with 19 or fewer natural teeth, those who had a total of 20 teeth or more, including both natural and artificial teeth, had significantly higher MMSE scores than those who had 19 or fewer natural and artificial teeth combined. Conclusion The number of natural teeth was significantly associated with the cognitive function, especially the calculation ability, and the use of artificial teeth was associated with the preservation of the cognitive function in community-dwelling elderly individuals.

Validity of the self-reported number of natural teeth in Japanese adults

AIM

The aims of this research were to assess the validity of self-reporting of the number of teeth by comparing the number with that obtained through clinical dental examinations, and to investigate factors affecting the discordance between the two measures.

METHODS

Self-administered questionnaires and dental examinations were conducted among 1152 dentate community residents in Japan. The validity of the patients' reports of the number of teeth was assessed by comparing the self-reported number with that determined at the clinical examination. Factors affecting the absolute value of the difference between the self-reported number of teeth and the number at clinical examination were investigated using a multivariate analysis.

RESULTS

Overall, 47.5% of participants had perfect agreement in their self-report with the clinical examination. There was a slight tendency toward underestimation of the number of natural teeth by self-reporting. Pearson's correlation coefficient was 0.80, and the intraclass correlation coefficient was 0.78 for all patients. Decayed, filled, sound teeth, and fixed prosthetic pontics were significantly associated with the absolute value of the difference between self-reports and clinical examinations.

CONCLUSIONS

Patients' reported number of remaining teeth, the data for which were collected via the questionnaire, provided reasonably valid data on the actual number of teeth within a population group.

Therapeutical attitudes in tooth supported overdentures with ball attachements. Case report

Tooth supported overdenture with ball attachments has a number of advantages in prosthetics, but presents some difficulties as well, which sometimes make impossible the use of these anchoring systems; these difficulties should be well known. In this regard we present a suggestive case. It is the case of a patient, aged 57, who came for treatment, suffering from subtotal maxillary and mandibular edentulism (present 11 and 21, respectively 33 and 43), previously having an overdenture prosthesis on natural teeth, with special systems - ball attachment type, dissatisfied with the treatment (due to repeated fractures and functional intolerance to dentures). Clinical examination revealed an increase of the vertical dimension of occlusion and reduced prosthetic space at a correct, functional DVO value, aspects that were explaining the patient's reported complaints. As a therapeutic approach, having into consideration the balance conditions that were favorable for complete dentures and the large ball attachments volume, which did not allow keeping them at a functional DVO at any of the jaws, and the relatively young age of the patient, it was decided to remove the ball attachments and to keep the teeth for a simple overdenture, both to the maxillar and the mandible, over coronary reduced teeth, enough to allow the denture thickness at a functional DVO. Good end result of prosthetics, with stable, functional dentures, which were well tolerated and offered satisfaction to the patient, have led to an increased quality of life.