The Significance of Marginal Gap and Overextension Measurement in the Evaluation of the Fit of Complete Crowns

2005 ◽  
Vol 6 (4) ◽  
pp. 26-37 ◽  
Author(s):  
Arne F. Boeckler ◽  
Anke Stadler ◽  
Jürgen M. Setz
Keyword(s):  
Zinc Oxide ◽  
Subjective Evaluation ◽  
Important Criterion ◽  
Objective Data ◽  
Regression Analyses ◽  
Marginal Gap ◽  
Marginal Fit ◽  
Subjective Evaluations ◽  
Pearson Test ◽  
Magnification Level

Abstract Introduction An important criterion for the success of a crown is marginal fit. However, in the patient's mouth fit can only be evaluated by subjective methods. This study describes the correlation between objective marginal fit and its subjective evaluation by dentists and dental technicians. Materials and Methods Thirty human premolars and molars were randomly divided into six groups and prepared with a shoulder. For each of the six groups, complete crowns were made of different alloys and technologies (casting: AuAgCu, AuPdPt, PdAgAu, CoCrMo, and Ti; milling: Ti). The crowns were cemented with provisional cement. Ten dentists and 10 technicians were asked to evaluate the fit of the crowns with a new dental explorer. The crowns were then cleaned and cemented with a zinc-oxide-phosphate-cement. The marginal gap and a possible overextended margin of the crowns were examined under a special 4x light microscope with a magnification level of 560 X. The means of the gaps and the overextended margins were calculated for each group. Significances were detected by analysis of variance (ANOVA) and the post-hoctest (Bonferroni, p<0.05). Correlations between objective measuring and subjective evaluation were evaluated using the Pearson test. The influence of the measured values on the subjective evaluation was determined by regression analyses. Results Crowns made from different alloys and technologies showed partly significantly (p<0.05) different marginal gaps (mean ranging from 35ìm to 92ìm) and significantly (p<0.05) different overextended margins (mean ranging from 40ìm to 149ìm). There were significant correlations (p<0.05) between subjective findings and objective data. Significant correlations (p<0.01) were also found between the subjective findings of dentists and technicians. Compared to the marginal gap, only the overextended margin had a significant influence (p=0.00) on the subjective evaluations of the clinicians. Conclusion Crowns from different alloys and technologies showed differences in marginal fit. Marginal gap and the overextension of the crowns significantly correlated with the subjective evaluation of their fit by dentists and dental technicians. For the decision of the clinicians, whether a crown is acceptable, overextension was more important than marginal gap. Citation Boeckler AF, Stadler A, Setz JM. The Significance of Marginal Gap and Overextension Measurement in the Evaluation of the Fit of Complete Crowns. J Contemp Dent Pract 2005 November; (6)4:026-037.

scholarly journals Evaluation of marginal fit and microleakage of monolithic zirconia crowns cemented by bio-active and glass ionomer cements: In vitro study

2020 ◽  
Vol 23 (1) ◽  
Author(s):  
Radwa Hamdy Aboelenen ◽  
Ashraf Mokhtar ◽  
Hanaa Zaghloul
Keyword(s):  
Glass Ionomer Cement ◽  
Glass Ionomer ◽  
Marginal Gap ◽  
Marginal Fit ◽  
Group I ◽  
Significant Difference ◽  
Zirconia Crowns ◽  
Monolithic Zirconia ◽  
Ionomer Cement ◽  
Gap Values

Objective: To evaluate the marginal fit and microleakage of monolithic zirconia crowns cemented with bioactive cement (Ceramir) compared to that cemented with glass ionomer cement and to evaluate the effect of thermocycling on marginal fit. Materials and methods: Twenty sound human molar teeth were prepared to receive a monolithic zirconia crowns. Teeth were divided randomly into two equal groups according to the type of luting cement. Group I: glass ionomer cement and group II: Ceramir cement. After cementation, the vertical marginal gap was assessed by using stereomicroscope before and after thermocycling. Twenty equidistant measurement points were taken for each crown. Leakage assessment was carried out using Fuchsin dye penetration followed by digital photography under a stereomicroscope. Data were analyzed by Mann-Whitney U test to compare between the two luting cements. Wilcoxon signed-rank test was used to evaluate the effect of thermocycling on the marginal fit (P ≤ 0.05)
Results: Whether before or after thermocycling, the results showed no significant difference between the marginal gap values of the two tested groups. For both groups, there was a significant increase in marginal gap values after thermocycling. Also, there was no significant difference between leakage scores of the two tested groups. Conclusions: Similarity in the physical properties and chemical composition of the two cements result in a non- significant effect on the vertical marginal fit and the extent of microleakage of translucent zirconia crowns.  Thermocycling had a negative impact on the vertical marginal gap of the two tested luting agents.

scholarly journals Building a Framework of Evaluating Human–Environment Relationships: Considering the Differences between Subjective Evaluations and Objective Assessments

2019 ◽  
Vol 12 (1) ◽  
pp. 167
Author(s):  
Ying Liu ◽  
Wei Deng ◽  
Li Peng
Keyword(s):  
Subjective Evaluation ◽  
Objective Assessment ◽  
Human Environment ◽  
Subjective Evaluations ◽  
The Matrix ◽  
The Difference ◽  
Objective Basis ◽  
And Behavior ◽  
Attitudes And Behavior ◽  
The Relationship

The human–environment relationship is bidirectional, meaning that human attitudes and behavior to nature are at the root of environmental change, while changes in the environment affect human attitudes and behavior. It is necessary to analyze the human–environment relationship from two aspects: (a) Whether there is a good objective basis for maintaining an environment, and (b) whether people report that they are satisfied with that environment. This study attempted to construct a framework to evaluate the human–environment relationship considering these two aspects. The framework consists of three parts: Traditional evaluation, indicator construction, and evaluation considering the relationship between subjective and objective assessment. Traditional evaluations consist of subjective evaluations and objective assessments. Indicator construction focuses on putting forward indicators that quantitively evaluate the human–environment relationship, considering the results of objective assessments and subjective evaluations. The indicators introduced in this study include MD (match degree) and OSC (objective assessment and subjective evaluation comparison) to explain the difference and the relationship between objective assessments and subjective evaluations of the environment. Then, based on the indicator value, a matrix containing four situations (Match-H, Match-L, H-L, and L-H) was constructed to explore why a human–environment relationship may not be harmonious. Since the upper Minjiang River basin is a typical area, because of its intensive human activity, as well as its fragile ecological environment, this study chose it as a case study and used it to verify the framework. Through the framework construction and application, this study found that: (1) The framework of this study provided a more comprehensive method to evaluate the human–environment relationship; (2) as the subjective evaluation was based on individual comprehensive tradeoffs, the evaluation combining the subjective and objective assessment was more accurate; (3) environmental conditions were the basis, and human activities were the key factors, for the coordination of human–environment relationships; so the matrix put forward in this study was necessary for finding the cause of human–environment incongruity.

Marginal Fit of Heat-pressed vs CAD/CAM Processed All-ceramic Onlays Using a Milling Unit Prototype

2008 ◽  
Vol 33 (6) ◽  
pp. 644-650 ◽  
Author(s):  
S. Reich ◽  
S. Gozdowski ◽  
L. Trentzsch ◽  
R. Frankenberger ◽  
U. Lohbauer
Keyword(s):  
Clinical Relevance ◽  
Clinical Performance ◽  
Important Influence ◽  
Marginal Gap ◽  
Marginal Fit ◽  
All Ceramic ◽  
Cad Cam ◽  
Ceramic Restorations

Clinical Relevance The marginal fit of all-ceramic restorations has an important influence on the clinical performance and lifetime of adhesively luted restorations. In proximal boxes, an average marginal gap of less than 100 μm is claimed. These clinical requirements are fulfilled by both processing procedures.

The Marginal Fit of CAD-CAM Zirconia Cores with Different Proximal Margin Configurations

2007 ◽  
Vol 330-332 ◽  
pp. 1409-1412
Author(s):  
O.E. Puntsag ◽  
E.K. Bae ◽  
Jae Hoon Lee ◽  
Keun Woo Lee
Keyword(s):  
Statistical Difference ◽  
Marginal Gap ◽  
Proximal Margin ◽  
Marginal Fit ◽  
Group I ◽  
Metal Ceramic ◽  
Cad Cam ◽  
The Mean ◽  
Tooth Axis

This study evaluated the marginal fit of CAD-CAM Zirconia cores with different proximal height. Thirty Zirconia cores and ten metal ceramics crowns were used to evaluate the marginal gap. The marginal fit was determined to be perpendicular to the tooth axis between the most apical point on the coping margin (core) and the reference marks on the mesial, distal, labial, and palatal surfaces of the die at several key stages of crown fabrication; before porcelain built-up, after body porcelain built-up, and after glazing. Additionally, an opaque stage for the metal ceramic copings was compared as well. Each measurement was carried out with a microscope. The means of gaps among the groups were 58±27 -m, 69±23 -m, 89±29 -m and 80±28 -m, groups I, II, III and IV, respectively. In relation to the proximal and labiopalatal surfaces there were no statistical difference among the groups, except group I. No significant differences were observed in firing stages of all groups. The findings of this study showed that the mean marginal gap of Zirconia cores with different proximal heights fell well within the acceptable clinical ranges.

scholarly journals Marginal Fit of Temporary Restorations Fabricated by the Conventional Chairside Method, 3D Printing, and Milling

2021 ◽  
Author(s):  
Mahsa Mohajeri ◽  
Sara Khazaei ◽  
Fariborz Vafaee ◽  
Farnaz Firouz ◽  
Somayeh Ghorbani Gholiabad ◽  
...  
Keyword(s):  
3D Printing ◽  
Acrylic Resin ◽  
Marginal Gap ◽  
Canine Tooth ◽  
Marginal Fit ◽  
Implant Abutment ◽  
The Mean ◽  
The Difference ◽  
Gap Data

Objectives: This study aimed to compare the marginal fit of temporary restorations fabricated by the conventional chairside method, 3D printing, and milling. Materials and Methods: In this in vitro, experimental study, 14 temporary restorations were conventionally fabricated over an implant abutment and analog that had been mounted in a phantom model at the site of canine tooth, using auto-polymerizing acrylic resin and putty index. In digital manufacturing, the original model was scanned, and the final restoration was designed. Fourteen temporary restorations were milled out of polymethyl methacrylate (PMMA) blocks, and 14 others were printed by a 3D printer. Temporary crowns were placed on the abutment, and images were obtained from specific areas under a stereomicroscope at x100 magnification to measure the amount of marginal gap. Data were analyzed using one-way ANOVA and Tukey’s test (α=0.05). Results: The mean marginal gap values for the temporary crowns in the 3D printing, milling, and chairside groups were 91.40, 75.28 and 51.23 µm, respectively. The crowns that were conventionally fabricated chairside exhibited the lowest marginal gap, and the difference in this respect was significant among the three groups (P<0.05). Conclusion: Temporary crowns fabricated by the chairside method showed significantly smaller marginal gap; however, the marginal gap of all three groups was within the clinically acceptable range.

scholarly journals Assessment of Personal Relaxation in Indoor-Air Environments: Study in Real Full-Scale Laboratory Houses

2021 ◽  
Vol 18 (19) ◽  
pp. 10246
Author(s):  
Yoshitake Nakayama ◽  
Norimichi Suzuki ◽  
Hiroko Nakaoka ◽  
Kayo Tsumura ◽  
Kohki Takaguchi ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Indoor Air ◽  
Subjective Evaluation ◽  
Objective Evaluation ◽  
Subjective Evaluations ◽  
Volatile Organic ◽  
The Relationship ◽  
Electroencephalogram Eeg ◽  
Human Sense

The relationship between chemical concentrations in indoor air and the human sense of comfort and relaxation have been reported. We investigated the effect of the sum of volatile organic compounds (ΣVOCs; sum of 79 VOCs) on the level of relaxation in two laboratory houses with almost identical interior and exterior appearances. The electroencephalogram (EEG) was monitored to evaluate the degree of personal relaxation objectively. The experiments were conducted in laboratory houses (LH) A and B with lower and higher levels of ΣVOCs, respectively. A total of 168 healthy volunteers participated, who each performed the task for 20 min, followed by a 10-min break, and EEG was measured during the break. Simultaneously as subjective evaluations, the participants were asked to fill a questionnaire regarding the intensity of odor and preference for the air quality in each LH. The subjective evaluation showed a significant association between ΣVOCs and participants’ relaxation (OR: 2.86, 95%CI: 1.24–6.61), and the objective evaluation indicated that the participants were more relaxed in the LH with lower levels of ΣVOCs than that with higher levels (OR: 3.03, 95%CI: 1.23–7.50). Therefore, the reduction of ΣVOCs and odors in indoor air would have an effect, which is the promotion of relaxation.

Influence of Prior General Knowledge on Older Adults’ Takeover Performance and Attitude Toward Using Conditionally Automated Driving Systems

2021 ◽  
Vol 65 (1) ◽  
pp. 1327-1331
Author(s):  
Huiping Zhou ◽  
Makoto Itoh ◽  
Satoshi Kitazaki
Keyword(s):  
Older Adults ◽  
Driving Simulator ◽  
Subjective Evaluation ◽  
Full Range ◽  
The Elderly ◽  
Limited Range ◽  
General Knowledge ◽  
Automated Driving ◽  
Subjective Evaluations ◽  
Positive Attitudes

This study aims to investigate the influence of general knowledge, which denotes·driving automation’s taxonomy, definitions, function, driver role, and the request to intervene (RtI), on older adults’ takeover performance when using conditionally driving automation (DA), and to clarify the influence of knowledge on drivers’ attitudes toward DA. We introduced two types of DAs: full range and limited range. A driving simulator (DS) experiment was conducted to collect data, including driving behavior in taking over vehicle control and driver’s subjective evaluation of the DA. Data were collected from 36 elderly (mean age = 71.4±4.8 years) and 36 non-elderly (mean age = 40.8±9.5 years) participants. The results showed significant differences between the elderly and non-elderly, such that educating knowledge had a greater influence on the older adults, that is, instructing knowledge to the drivers contributed to a statistical increase in successful takeover rate from 0.66 to 0.80, but no effect was seen on either the response time or the maximum steering angular velocity. Furthermore, more frequent glance behavior of looking forward from a non-driving related task was observed in the educated groups. Self-rating scores of subjective evaluations revealed that older adults who were given the knowledge had a higher level of trust in and expectation from the DA, and more confidence in comprehending system functions. This study demonstrates the necessity of general knowledge instruction to enhance drivers’ positive attitudes toward DA.

Psychophysiological Effects by Interaction with Mental Commit Robot

2002 ◽  
Vol 14 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Teruaki Mitsui ◽  
◽  
Takanori Shibata ◽  
Kazuyoshi Wada ◽  
Kazuo Tanie ◽  
...  
Keyword(s):  
Mood State ◽  
Subjective Evaluation ◽  
A Priori ◽  
Mood States ◽  
Autonomic Response ◽  
A Priori Knowledge ◽  
Physical Interaction ◽  
Profile Of Mood States ◽  
Electrodermal Response ◽  
Subjective Evaluations

We have been working on research and development of mental commit robot which aims to provide humans mental effects such as enjoyment and relaxation. In the previous research, we have performed subjective evaluation of mental commit robot by some interview forms. The results showed physical interaction improved subjective evaluations. Moreover, a priori knowledge of a subject had influence into subjective interpretation and valuation. In this paper, we applied physiological measurements to investigate influence to human by physical interaction with mental commit robot. As physiological measurements, we applied the electrocardiogram (EGG), respiration rate and the electrodermal response (EDR). And we measured mood state and liking for the object by using the profile of mood states (POMS) and SD method. The finding of experiments suggested changes of autonomic response and mood state caused by physical interaction with mental coconut robot. Moreover, it was suggested that there were some differences in autonomic response by subjectivity.

Assessing the comfort of functional fabrics for smart clothing using subjective evaluation

2018 ◽  
Vol 48 (8) ◽  
pp. 1310-1326 ◽  
Author(s):  
Melkie Getnet Tadesse ◽  
R Harpa ◽  
Y Chen ◽  
L Wang ◽  
V Nierstrasz ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Subjective Evaluation ◽  
Human Perception ◽  
Evaluation Procedure ◽  
Smart Clothing ◽  
Subjective Evaluations ◽  
Skin Contact ◽  
Functional Textiles ◽  
Textile Fabrics ◽  
And Control

Sensory investigations of the functional textiles could be an alternative for the quality inspection and control of the products. The purpose of this research is to use subjective evaluation technique for assessing the tactile comfort of some functional textile fabrics based on AATCC Evaluation procedure 5-2011. Blind subjective evaluations and visual subjective evaluations were performed for sensory investigation. Ten fabric-skin-contact and comfort-related sensory properties were used to evaluate the handle of the functional textile fabrics. The reliability of the sensorial data obtained by subjective tests was evaluated using statistical data analysis techniques. A minimum and maximum consensus distances recorded were 0.58 and 1.61, respectively, using a descriptive sensory panel analysis and proves the consistency and similar sensorial perception between panelists. The Pearson correlation coefficient between panelists was up to 96% and hence a strong agreement between the panelist’s judgment. The results allowed to consider the subjective evaluation using a panel of experts could be validated in the case of functional fabrics. For functional textiles, additional visual subjective evaluation should be considered to have a similar human perception in addition to blind subjective evaluation.

Measurement and Analysis of Pressure Distribution on the Bed

1995 ◽  
Vol 39 (5) ◽  
pp. 297-300 ◽  
Author(s):  
Se Jin Park ◽  
Min Cheol Whang ◽  
Chang Bum Kim
Keyword(s):  
Pressure Distribution ◽  
Subjective Evaluation ◽  
The Body ◽  
Force Sensing ◽  
Objective Data ◽  
Short Term ◽  
Measurement And Analysis ◽  
Verification Test ◽  
The Difference ◽  
Body Pressure Distribution

A new measurement system for body pressure on a bed was developed in this study. The thin film pressure sensor (PSR: Force Sensing Resistor) of an elastomer-type was used to prevent the distortion of contact pressure. The pressure distribution was measured by FSR and displayed on the monitor by color-coded contour patterns. The body pressure distribution and the objective data for four beds with different firmness were observed for possible correlation with the subjective evaluation. Ninety-eight occupants subjectively evaluated five beds for a short-term lying session about 1 hour. The pattern of the pressure distribution was analyzed to correlate approximately with the difference between comfortable and uncomfortable bed. The verification test on the recommended bed was performed by other twenty subjects through one week.

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