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A comparison of training methods in cavity preparations in primary teeth for preclinical dental students

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A comparison of training methods in cavity preparations in primary teeth for preclinical dental students

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Content A COMPARISON OF TRAINING METHODS IN CAVITY PREPARATIONS IN PRIMARY TEETH FOR PRECLINICAL DENTAL STUDENTS by Erna Surjadi A Thesis Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE (Applied Biometry) May 19 90 UMI Number: EP54929 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Oissertafen P W M i's M n g UMI EP54929 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 UNIVERSITY OF SOUTHERN CALIFORNIA THE GRADUATE SCHOOL UNIVERSITY PARK LOS ANGELES, CALIFORNIA 90007 B ’ 90 S9él T h is thesis, w ritte n by SuRJâBl un d e r the d ire ctio n o f h'ÙX.... .Thesis C o m m ittee , and a pp ro ve d by a ll its members, has been p re sented to and accepted by the D e an o f T he G radu ate S chool, in p a r tia l fu lfillm e n t o f the requirem ents f o r the degree o f (APPLIED BIOMETRY) Master o Dean D a te ..3 ^ 1 ... H . i'l THESIS COMMITTEE \ nCTOR_KIPNTS__Ph._D ^ Chairm an STANLEY Py Aig^Ph- RICHARD UDIN DDS ACKNOWLEDGEMENTS I would like to express my deep appreciation and gratitude to my comittee Chairman, Dr. Victor Kipnis, for his continous support, guidance, encouragement and patience during the development of this thesis as well as for his valuable excellent teaching and supervision involving many other projects to me as his graduate assistant, which contributes valuable assets to complete my thesis. I am deeply in debt and thankful to Dr. Stanley P. Azen for accepting me into Biometry program, opening the research opportunity involvement as well as for his continous support throughout my academic experience and thesis development as an excellent teacher and counselor. I would also like to extend my appreciation to Dr. Richard Udin DDS for his valuable insight to the study and contributions as well as for his wonderful suggestions during the development of this thesis. My special gratitude to my lovely family: my husband. Ferry, and my sons, Johan and Jesse, for their patience, understanding, support and encouragement. ii TABLE OF CONTENTS page ACKNOWLEDGEMENTS ii LIST OF TABLES iv LIST OF FIGURES V Chapter I. Introduction 1 II. Material and Methods 4 III. Results 13 IV. Discussion 25 V. Conclusion and Recomendation 30 REFERENCES 31 APPENDIX 33 iii LIST OF TABLES page 1. SAMPLE SIZES AND GENDER DISTRIBUTION OF THE STUDENTS STRATIFIED BY METHOD OF TRAINING 13 2. PEARSON CORRELATION COEFFICIENT BETWEEN THE SCORES RECEIVED FROM GRADER 1 AND GRADER 2, FOR MIDTERM AND FINAL EXAMINATIONS 14 3A.MEAN SCORES OF THE STUDENTS' CAVITY PREPARATIONS RECEIVED FROM GRADER 1, GRADER 2 FOR MIDTERM AND FINAL EXAMINATIONS (FOR ALL STUDENTS) 16 3B.MEAN SCORES OF THE STUDENTS' CAVITY PREPARATIONS RECEIVED FROM GRADER 1, GRADER 2 FOR MIDTERM AND FINAL EXAMINATIONS (FOR FEMALE AND MALE STUDENTS) 17 4. RESULTS OF THE ANALYSIS OF VARIANCE (without controlling the gender). (a = 0.05) 19 5. RESULTS OF SIMPLE MAIN EFFECT ANALYSIS (without controlling the gender). (a = 0.03) 20 6. TUKEY PAIRWISE COMPARISON OF THE MEAN SCORES OF THE METHODS (without controlling the gender) (a = 0.03 ) 20 7. RESULTS OF THE ANALYSIS OF VARIANCE (when controlling the gender). ( a = 0.05 ) 21 8. TUKEY PAIRWISE COMPARISON OF THE MEAN SCORES OF THE METHODS OF TRAINING (CK = 0.03 ) . 22 9. RESULTS OF SIMPLE MAIN EFFECT ANALYSIS FOR FEMALE STUDENTS (a = 0.03). (For the interaction of method and grader) 2 2 10. RESULTS OF SIMPLE MAIN EFFECT ANALYSIS FOR FEMALE STUDENTS (a = 0.03). (For the interaction of method and phase) 2 3 11. RESULTS OF SIMPLE MAIN EFFECT ANALYSIS FOR MALE STUDENTS (a = 0.03). 24 iv LIST OF FIGURES page MEAN SCORE OF CAVITY PREPARATIONS AT MIDTERM EXAMINATION BY GRADER 1 15 MEAN SCORE OF CAVITY PREPARATIONS AT FINAL EXAMINATION BY GRADER 1 16 MEAN SCORE OF CAVITY PREPARATIONS AT MIDTERM EXAMINATION BY GRADER 2 17 MEAN SCORE OF CAVITY PREPARATIONS AT FINAL EXAMINATION BY GRADER 2 18 V CHAPTER I INTRODUCTION This thesis represents a statistical analysis of an experimental study carried out by members of the Pediatric Dentistry Faculty at the University of Southern California (use). School of Dentistry (Udin et al.). The experimental study sought to evaluate alternative training methods in cavity preparations for sophomore dental students, to the one currently used, namely, Typodont method. The traditional training method utilizes ivorene teeth, which are mounted in a Typodont model. These teeth are made of an acrylic-like material and are morphologically similar to natural maxilary and mandibulary primary teeth. A problem associated with the ivorene teeth is that they arJ homogenous acrylic teeth that do not have various layers as found on natural teeth. The hardness of the acrylic model is different from that of the natural tooth. Because of the limitations imposed by the homogeneity of the material, it may be difficult for the students to obtain an adequate image of an ideal cavity preparation with the Typodont} method. An alternative training method, simulating the conditions encountered when preparing natural teeth, may be helpful in training the students. The study was an attempt to evaluate such a method. The Cavidrill training method was first developed in conjunction with the University of Zurich, Department of Restorative Dentistry, Periodontology, and Preventive Medicine, and with the assistance of the Ivoclar Company (Losche, G.M, 1986). The Cavidrill, a base plate training device, is made of three layers of resin of urethane dimethacrylate. It was designed according to the color and hardness of the various layers of a natural tooth, which consists of enamel, dentin, and pulp. On the surface of the Cavidrill training device, outlines of various forms are drawn, approximating cavity preparation outlines. These consist of double thin black lines. According to Losche (1986), by removing the inner thin black line without touching the outer black line, the students can practice developing their tactile sensitivity as well as their sensitivity to color changes and to cavityj depth. In his 1986 article, he mentioned that: " It shows from the study that the use of Cavidrill in an operative dentistry department preclinical course considerably reduced the problems that usually occur in preparing acrylic teeth. Ideal cavity preparations were created faster and with more precision. Students used fewer of the expensive acrylic teeth and were far more likely to see success. Also, students were better able to judge a successful preparation" (p.701). The above mentioned article did not present any data to substantiate these findings and to date there has not been any study that quantitatively demonstrated the success of the Cavidrill training method over that of the Typodont. For that reason, members of the Division of Pediatric Dentistry, Department of Developmental Dentistry of the USC School of Dentistry designed such an experimental study. The main purpose of this study was to determine whether the efficiency of the Cavidrill training method was significantly different from the traditional Typodont method. The evaluation was based on formal examination of the students' cavity preparations evaluated by two graders. CHAPTER II MATERIAL AMD METHODS 11.1. The Participants The participants in the study were sophomore dental students in the School of Dentistry, USC, who enrolled in a Preclinical Pediatric Dentistry course. There were 115 students involved. 11.2. The Study II.2.1. Design Five different laboratories were formed. Preclinical students were assigned alphabetically to a particular laboratory alphabetically. Each laboratory was then instructed in one of four specific training techniques (see below). Two laboratories received the control trainings (Typodont method). Two graders evaluated student's cavity preparations on a midterm and a final examination as well as on weeklyj assignments. The efficiency of each method was based on the scores of the students' cavity preparations on the midterm 4 and the final examinations. The examination evaluated the students according to six criteria considered as the "critical errors" for cavity preparation (see Appendix A) . However, this evaluation was used for both examinations. The six criteria were: occlusal outline, pulpal depth, extensions, axial wall, gingival floor, and finishing. The total score was the average score earned on these six criteria. This evaluation was based on the Typodont model, and was used in grading the students weekly in the Typodont method, but not in the Cavidrill method. II.2.2. Method of Training All students underwent an orientation session and attended lectures concurrently with the laboratory sessions which described the cavity preparations in primary teeth. The students from each laboratory were trained using â specific training device according to the method to which each laboratory was assigned. The methods were as follows : 1. The Cavidrill method (Lab A) : Students were trainee using the Cavidrill base plate training device exclusively for a six-week period. 2. The Cavidrill/Typodont method (Lab B): Students were trained using the Cavidrill model for the first three weeks, and then the Typodont model for the next three weeks. 3. The Typodont method (Lab C and Lab E): Students were trained using the Typodont model for their cavity preparation exercises for the six-week period. 4. The Typodont/Cavidrill method (Lab D): Students were trained using the Typodont model for the first three weeks, and then the Cavidrill model for the next- three weeks. The students were trained in the following sequence : 1. A given method of training was provided by a trained instructor during a six-week period. An instructor taught one and only one of the methods. 2. On the seventh week, at the midterm examination, two graders (not the instructors) independently evaluated the students' cavity preparations using Typodont "critical errors" evaluation. The cavity preparations were done on the ivorene Typodont teeth which were mounted in plastic blocks. 3. After the midterm, the students were involved in unrelated projects for four weeks. 4. The restorative training resumed two weeks before the final examination. During this phase, all the! students in all five laboratories received Typodont training only. 5. The final examination was administered following this additional training on ivorene teeth with the same Typodont critical errors evaluation as was used for the midterm examination. II.2.3. Remark Since the students were assigned to a particular method of training according to their names alphabetically, this study was not a truly randomized comparison of the four methods. The primary hypothesis was to find out whether the Cavidrill method could be as successful as the Typodont one. In planning this study, no calculation was made to estimate the sample size needed to demonstrate a statistically significant difference between the different methods. Further, the instrument for grading was notj necessarily appropriate for evaluating all methods of training since the Typodont "critical errors" evaluation on ivorene Typodont teeth was used for all four methods. II.3. Data Analyses Statistical analysis utilized the analysis of variance (ANOVA) technique. Four factors were tested: 1. Method of training: a) the Cavidrill method; b) the Cavidrill/Typodont method; c) the Typodont method; and d) the Typodont/Cavidri11 method. This factor was tested to analyze whether there were any significant differences among the mean scores of each of the four methods. 2. Phase of the study: a) the first phase - the midterm examination; b) the second phase, - the final examination. This factor was tested because a different: condition existed between the midterm and the final examinations. As was mentioned above, all students were trained to use the Typodont model two weeks before the final examination. In contrast, the students in the Cavidrill method used only the Cavidrill model before the midterm examination. 3. Grader; There were two graders who evaluated the students' cavity preparations. This factor was tested to determine inter-grader variability between the mean scores. 4. Gender: This factor was tested to analyze whether there was any difference between the mean score of the I female students versus the mean score of the male students' cavity preparations. Before applying the ANOVA, the distribution of the scores was examined for normality using the Shapiro-Wilk statistic. For each training method, we tested the data separately for each of the two phases, and each of the two graders. Since testing each method was considered a separate experiment, the experiment-wise significant level! (0.05) was adjusted based on the Bonferronni's inequality. As a result, the null hypothesis of a normal distributions was rejected if the p-value in each individual test was less than 0.0125 (0.05/4) The skewness of the distributions was examined by using box plots. A normal distribution is required to perform appropriately the parametric ANOVA. The technique can also be performed if the distribution does not deviate radically from normality. This is because ANOVA is robust to departures from normality. If the distribution were substantially non-normal, a non-parametric procedure or a transformation of the data would have been performed. In order to examine the relationship of the scores between the two graders, Pearson correlation coefficients were calculated for each phase of the study. A large correlation, (e.g., > 0.70), was interpreted as a "strong" agreement between the scores of the two graders. If a "strong" correlation was found, ANOVA would be performed oil the averaged scores. If a "moderate" correlation was found (e.g., between 0.3 0 and 0.70), then ANOVA would be performed on the individual scores from each grader. Following the completion of the preliminary data analysis, the scores of the students' cavity preparations 10 were submitted to the analysis of variance including an analysis of the gender factor. In the case of a significant interaction, the analysis would be followed by the simple main effect analysis. When a significant difference among the methods exist the analysis would be followed by the Tukey pairwise comparison. For the follow-up tests the significance level should be adjusted based on the Bonferronni's procedure. To perform the ANOVA, the Generalized Linear Model (GLM) procedure of the Statistical Software System (SAS, 1985) was used, because of an unbalanced design. This was due to missing data (some of the students did not attend the midterm or the final examinations) and to the unequal number of observations for the four different methods. The model for this design was the split plot, given by: ^ijkl = P + Oj + Ti + (ar)ji + ’ Ti(ji) + + (“®)jk + (6T)ki + ^ijkl (i = l,...,n;j = l,...,p; k = l,...,q; 1 = 1,...,r) where: Y = the score of the cavity preparations. 11 a = method of training ( p=4; j=1,2,3,4). r = phase of the study/the examinations ( r=2; 1=1,2). 7T = subject, participant of the study ( n total= 115, for method l(n^)= 24; method 2(n2)= 23; method 3(n^) = 44; method 4 (n^ ) = 24; so 1^=1, . . . , 24 ; i2=l,...,23 ; ig = 1,...,44 ; i^=l,...,24 ) . B = grader of the examinations ( q = 2 ; k=l,2). CKT = the interaction between the method and the phase of the study. aB= the interaction between the method and the grader. Br= the interaction between the grader and the phase of the study. aRr= the interaction between the method, the grader, and the phase of the study. 12 CHAPTER III RESULTS Table 1 shows the sample sizes and gender distribution' for the four methods of training. Note that the Typodont (control) method had more students than the other three methods. It also can be noted that the number of male students was about twice the number of female students. % Table 1 Sample Sizes and Gender Distribution of the Students Stratified by Method of training Method of Training Gender Cavidrill (N=24) Cavidrill/ Typodont (N=23) Typodont (N=44) Typodont/ Cavidrill (N=24) Total (N=115) Female Male 9 (38%) 15 (62%) 11 (48%) 12 (52%) 13 (30%) 31 (70%) 6 (24%) 18 (76%) 39 (34%) 76 (66%) The normality of the data was checked separately by grader, phase, and method (see Appendix 0) . The results showed that in most cases the scores were approximately normally distributed. The schematic box-plots of scores for the worst situations are presented in Figures D1 to D3 13 (Appendix D) . The box plots showed that the distributions did not deviate too far from normality. I To test agreement between the two graders in scoring students' cavity preparations, we calculated the Pearson correlation coefficients, overall and by gender (Table 2). The results for the midterm and the final examinations showed low to moderate agreements. Based on these results, data were not averaged but rather analyzed using the individual scores from each grader. Table 2 Pearson Correlation Coefficient Between the Scores Received from Grader 1 and Grader 2, for Midterm and Final Examinations. SOURCE MIDTERM FINAL ALL STUDENTS r — 0.51 ;(p<0.0001) (N = 112) r = 0.37 ;(p<0.0001) (N = 115) FEMALE STUDENTS MALE STUDENTS r = 0.44 r = 0.54 ;(p=0.0066) (N = 37 ) ;(p<0.0001) (N = 75 ) r = r = 0.52 ;(p=0.0006) (N = 39) 0.31 ;(p<0.0071) (N = 76) Note: r= Pearson correlation coefficient; N=total number of observations. Tables 3A-B and Figures 1 to 4 presents the mean score for each method for the midterm and final examinations. It is interesting to note that, for either grader the mean 14 score of the Cavidrill method for the midterm examination was the lowest while the mean score of the Typodont method was the highest. For the final examination the mean score of the Typodont method decreased while the mean scores of other methods increased, especially those for the Typodont/Cavidrill and the Cavidrill methods. Figure 1 Mean Score of Cavity Preparations at Midterm Examination by Grader 1 IZZl A ll 15 Figure2 Mean Score of Cavity Preparations at Final Examination by Grader 1 3JZ IZZl Malm Table 3A Mean Scores of the Students' Cavity Preparations Received from Grader 1, Grader 2 for Midterm and Final Examinations (For ALL STUDENTS) Phase of Study GRADER Method of Training CAVIDRILL (1) CAVIDRILL/ TYPODONT (2) TYPODONT (3) TYPODONT/ CAVIDRILL (4) MIDTERM 1 2.15 2.48 2.93 2.17 2 2.21 2.57 3.05 2.46 FINAL 1 2.54 2.63 2.75 -------- — ---------- 2.50 2 2.48 2.74 2.60 2.79 16 TâlDlë“3B- Mean Scores of the Students' Cavity Preparations Received from Grader 1, Grader 2 for Midterm and Final Examinations (For Female and Male Students) Method of Train ing MIDTERM EXAMINATION Grader 1 | Grader 2 FINAL EXAMINATION Grader I | Grader 2 F M F M F M F M 1 2.06 2.20 1.94 2.37 2 . II 2.80 2.06 2.73 2 2.06 2.79 2.50 2.63 2.59 2.67 3.14 2.38 3 2.69 3.03 3.04 3.05 2.42 2.89 2.42 2.68 4 2.08 2.19 2.75 2.36 2.75 2.42 2.83 2.78 Figure 3 Mean Score of Cavity Preparations at Midterm Examination by Grader 2 % I EZI AU WZk MaU 17 Figure 4 Mean Score of Cavity Preparations at Final Examination by Grader 2 E2D Au M tm O D OF TnA H O H e _ F^nwatm Ï///À MaXm III.1. Analysis for all Students The analysis of variance of these data (Table 4) showed that the mean score from grader 1 was not significantly different from that of grader 2. Since there was a 18 significant interaction between phase and method, analyses were then performed separately for these factors (Table 5). Table 4 Results of the Analysis of Variance (without controlling the gender) (a = 0.05) SOURCE TESTED p values 1 METHOD . 0098 PHASE . 1940 METHOD*PHASE . 0060 GRADER .0987 GRADER*PHASE .4981 METHOD*GRADER .1439 METHOD*PHASE* .8081 GRADER The simple main effect analysis showed that the difference among the mean scores of the methods was statistically significant only for the midterm examination, but not for the final examination (Table 5) . As Table 6 shows, this result was attributed to the differences between the mean scores of the Typodont and the Cavidrill methods. It also follows from Table 5 that the average scores for the midterm and final examinations were different for the Typodont method only. 19 Table 5 Results of Simple Main Effect Analysis (without controlling the gender) (a = 0.03) Testing METHOD for: | p Testing PHASE for: | p | MIDTERM EXAMINATION| <.001 FINAL EXAMINATION | > .03 CAVIDRILL METHOD(1) CAVIDRILL/TYPODONT(2) TYPODONT (3) TYPODONT/CAVIDRILL(4) > .03 > .03 < .03 > .03 Table 6 Tukey Pairwise Comparison of the Mean Scores of the Methods (without controlling the gender) (a = 0.03 ) SOURCE DIAGRAM COMPARISON TESTED MIDTERM FINAL METHOD 3 2 4 1 3 2 4 1 Note: The lines indicate for a non significant comparison. The highest mean score is on the most left of the diagram. III.2. Analyses stratified by gender III.2.1. For Female Students Analyses of variance for females (Table 7) revealed a significant interaction between method and grader. Thé interaction between method and phase was also significant. 20 Table 7 Results of the Analysis of Variance (when controlling the gender) (a = 0.05) SOURCE TESTED p(FEMALE) p(MALE) METHOD .0701 .0430 PHASE .4534 .3713 METHOD*PHASE .0483 .0239 GRADER .0053 .8763 GRADER*PHASE .5687 .5164 METHOD*GRADER .0294 .1527 METHOD*PHASE* .6761 .6613 GRADER The simple main effect analysis showed (Table 8) that for the midterm examination, the mean score of the Typodontj method was significantly different from the mean score of| the Cavidrill method, while other methods were not significantly different. In addition (Tables 9 - 10), analysis revealed that- the grader factor was significantly different for the Cavidrill/Typodont method only, while it was not significant for other methods. The phase factor was not significantly different for any method. At the final examination the mean score of the Cavidrill/Typodont method was significantly different from the mean score of the Cavidrill method, while the mean scores of other methods 21 were not different from each other. This result held onl^ for grader 2, but not for grader 1. Table 8 Tukey Pairwise Comparison of the Mean Scores of the methods of training (a — 0.03 ) SOURCE FEMALE MALE TESTED MIDTERM FINAL MIDTERM FINAL METHOD 3 4 2 1 2 4 3 1 3 2 1 4 3 2 4 1 Note: The lines indicate for a non significant comparison. The highest mean score is on the most left of the diagram. Table 9 Results of Simple Main Effect Analysis for Female Students (a = 0. 03) For the Interaction of Method and Grader: Testing GRADER for: | p Testing METHOD for| p CAVIDRILL METHOD CAVIDRILL/TYPODONT TYPODONT TYPODONT/CAVIDRILL > . 03 < . 03 > . 03 > . 03 GRADER 1 GRADER 2 >.03 <.005 22 Table 10 Results of Simple Main Effect Analysis Female Students (0£ = 0.03) For the Interaction of Method and Phase: Testing PHASE for: P Testing METHOD for:| P CAVIDRILL METHOD > .03 MIDTERM EXAMINATION| <.03 CAVIDRILL/TYPODONT > .03 TYPODONT > .03 FINAL EXAMINATION | >.03 TYPODONT/CAVIDRILL > . 03 III.2.2 For Male students It follows from Table 7 that the grader factor was not statistically significant for male students. There was, however, a significant interaction between method and phase. Further analyses (Table 11) did not show any significant difference between the mean scores of the midterm and the final examinations for any method. However, a comparison among the mean scores of the methods for the midterm examination revealed a highly significant difference (p<.001). This was because the mean score of the Typodont method was significantly different from that of the Cavidrill and the Typodont/Cavidrill methods, while it was not different for other methods. For the final 23 examination the mean scores of all methods were not significantly different. Table 11 Results of the Simple Main Effect Analysis for Male Students (a = 0. 03) Testing PHASE for: P Testing METHOD for:| P CAVIDRILL METHOD > . 03 MIDTERM EXAMINATION| <.001 CAVIDRILL/TYPODONT > .03 TYPODONT > .03 FINAL EXAMINATION | >.03 TY PODONT/CAVIDRILL > .03 Note: The raw data which were entried for these statistical analyses are presented in Appendix E 24 CHAPTER IV DISCUSSION The results of the analyses can be summarized as follows: Overall, the mean midterm examination scores for the four methods of training were significantly different. The mean score for the Typodont method was significantly greater than that for the Cavidrill method. The mean scores for other methods were not significantly different. The mean final examination scores for all methods were not significantly different. However, the results for the midterm and the final examinations, were significantly different only for the Typodont method of training and not for the other methods of training. When examining these data by gender, it was found also that for female students (according to grader 2 only), the mean final examination score for the Cavidrill/ Typodont method was significantly greater than that for the Cavidrill only method. On the other hand, according to grader 1, the mean scores of all methods were not different. For the male students the mean midterm 25 examination score for the Typodont method was significantly greater than that for the Cavidrill or the Typodont/ Cavidrill methods of training. Losche (1986) stated that the Cavidrill training method was noted to be successful in training students to accomplish ideal cavity preparations. In that study, it was reported that the students were able to develop better precision in creating an ideal preparation. In achieving an ideal cavity preparation and providing the knowledge to the students, the author maintained that the device was successful in its use for training preclinical students. However, based on the statistical analysis in the present study, the results do not tend to support the previous study. There are several limitations in the design of the study. One limitation was that the teeth used in both examinations were similar to the ivorene Typodont teeth. On the midterm, students from the Cavidrill method did not know how to image their primary cavity preparations on the Typodont teeth, because they did not use them in their Pediatric Dentistry preclinical training. This could 26 explain why the mean score of the Typodont method was statistically different from that of the Cavidrill method for the midterm but not for the final examination. The differences disappeared after the students were all trained to use the Typodont model two weeks before the final examination. The knowledge gained by using a similar model for the examinations seems to be very important for determining students' performance. This conclusion is supported by the result that the mean score of the Typodont method was higher than the mean score of the Cavidrill method for the midterm examination. Even for the Cavidrill/Typodont and the Typodont/Cavidrill methods, in which both training methods were combined, the mean scores were higher than the mean score of the Cavidrill only method, although the differences were not statistically significant. Interestingly, for the final examination the scores of the Cavidrill method increased and as a result, they became closer to the mean score of the Typodont method, which conversely decreased. Also, after the midterm examination all students were involved in unrelated projects for four weeks. This may indicate that the familiarity of using a 27 similar model during the training and for the examinations played such an important role. Another limitation was that the criteria for the critical errors evaluation used for the Cavidrill method during the training period were somewhat different from the Typodont criteria on the examinations (Appendix B) . The students from the Cavidrill method were sensitized to an ideal cavity preparation based on the factors of the Cavidrill grade evaluation sheet, not based on that of the Typodont. On both examinations, the model used for testing the efficiency of the Cavidrill and the Typodont devices was the Typodont model itself, which could have biased the results of this study. Therefore, this test when applied to the Cavidrill method would likely result in poorer performance than when a test which was unrelated or equally related to both methods would have been used. For testing whether the students improve their cavity preparation skills by using a certain training device, it would be better to test the students in the "real environment." Thus, the model used in both examinations 28 should be real primary teeth of children; although, it is difficult to get good primary teeth as a model. Although grading was accomplished blindly, the scores from one grader placed the female students' mean score in the Cavidrill/Typodont method at a significantly higher level than that of the Cavidrill method; while for the male students, the mean scores of all methods were not significantly different. This situation held only in case of grader 2, and not for grader 1. It is recommended that a pilot study evaluate differences in grading between graders prior to main study. If the real teeth were used in the experimental study for the midterm and the final examinations, it would be important to use the same training device consistently during the whole training period in order to examine the efficiency of each method. With the Typodont teeth actually used in the two examinations, there was no difference found among the methods at the final examination. The differences between the results of the midterm and final examinations suggest that the introduction of the Typodont teeth for all methods during the two weeks prior to the final examination might have eliminated the differences among the methods. The statistical analysis seems to support this conclusion. 29 CHAPTER V CONCLUSION AND RECOMENDATION Unfortunately, the results found in this study, interesting as they are, cannot be declared as final. There is a possibility of several biases depending on the type of model and the criteria used for evaluation. As a result, jthe Typodont method of training may have produced higher scores than any of the other methods only due to these biases. So, it would be better to conduct a new experimental study with the following improvements: - using real primary teeth as the model used for the examinations. - not training the Cavidrill group to use the Typodont model (until after the end of the study) . - finding methods to facilitate self-evaluation in the real teeth for both groups. - applying a real randomized mechanism to get a ballanced number of participants per group. 30 REFERENCES 1.Àcorde, Project: Cavitv Preparations for Amalaam and Tooth-colored Materials. Washington, National Àudio-visual Center (GSÀ), Project Àcorde, a consortium on Restorative Dentistry Education, 1975 2.Àfifi AA, Azen SP: Statistical Analvsis. a Computer Oriented Approach. New York, Academic Press, 1979 3.Borg WR and Gall MD: Educational Research. 5th Ed. New York, Longman, 1989 4.Chayes, Herman ES: How to Acquire Abilitv and Skill in Cavitv Preparation. New York, Chayes Dental Instrument Corporation, Press of Stettiner Bros, 1934 5.Cratty, Bryant J: Movement Behavior and Motor Learning. 3rd Ed. Philadelphia, Lea & Febiger, 1973 6.Fell, Philip H: A Theory of Motor Performance and its Applications to preclinical Dental Skill Acquisition. Journal of Dental Education. April 1989;53, No.4:226- 232 7.Freund, Rudolf J, Litter, Ramon C, Spector, Philip C: SAS Svstem for Linear Models for Version 5, second edition. Cary, NC, 1986 8.Hardison, David J, Skeeters, Milton T: A quantifying grid for the Cavidrill training aid. The Journal of Practical Dentistry, Illinois, Number 5, 1988, Volume 19 9.Harty FJB, Ogston R: Consice Illustrated Dental Dictionarv. Bristol, Wright, 1987 lO.Issac S and Michael WB: Handbook in Research Evaluation. 2nd Ed. San Diego, EdITS, 1981 11.Kirk RE: Experimental Design. Procedures for Behavioral Sciences, second edition. Monterey, California, Brooks/Cole Publishing Company, 1982 31 12.Losche GM, Benner B, Roulet JF: A didactic training aid for use in preclinical operative dental education. The Journal of Practical Dentistry, Illinois. 1986;11, Vol.17:699-701 13.Mandel, ID: Forty years of research - it's impact on dental practice. International Dental Journal. FDI, March 1989;39, No.1:7-12 14.Microsoft, The Peter Norton: Programmer's Guide to the IBM PC, The ultimate reference guide to the entire family of IBM personal computers. Washington, Microsoft Press, 1985 15.SAS Institude Inc: SAS User's Guide : Basics. Version 5 Edition, Cary, NC,1985 16.SAS Institude Inc: SAS User's Guide : Statistics. GLM; procedure. Version 5 Edition, Cary, NC, 1985 17.Udin RD, Bamrud JD, Johnson R, Yaari A: The effectiveness of the Cavidrill Training Aid in the Preclinical Instruction of Sophomore Dental Students. (submitted for publication). 18.Waldman, HB: Another perspective on children's dental needs and demand for services during the 1980s, Journal of Dentistrv for children. Chicago, ASDC, 1987; September-October: 344-348 19.Zar JH: Biostatistical Analvsis. Second Edition. Englewood Cliffs, N.J, Prentice-Hall, Inc., 1984 32 LIST OF APPENDIX A. UNIVERSITY OF SOUTHERN CALIFORNIA PRECLINICAL PEDIATRIC DENTISTRY LAB TYPODONT GRADE SHEET B. UNIVERSITY OF SOUTHERN CALIFORNIA PRECLINICAL PEDIATRIC DENTISTRY LAB CAVIDRILL GRADE SHEET C. P VALUES RESULTING FROM TEST OF NORMALITY OF THE SCORES RECEIVED FROM GRADER 1, GRADER 2, AND STRATIFIED BY GENDER (a=0.0125) Dl. BOX PLOTS OF SCORES IN SITUATIONS OF NON-NORMALITY (ALL STUDENTS) D2. BOX PLOTS OF SCORES IN SITUATIONS OF NON-NORMALITY (GENDER=FEMALE) PHASE 1 D3. BOX PLOTS OF SCORES IN SITUATIONS OF NON NORMALITY (GENDER=FEMALE) PHASE 2 E. SCORES OF CAVITY PREPARATIONS FROM GRADER 1, GRADER 2, AT MIDTERM AND FINAL EXAMINATION 33 APPENDIX Al UNIVERSITY OF SOUTHERN CALIFORNIA PRECLINICAL PEDIATRIC DENTISTRY LAB TYPODONT GRADE SHEET Tooth # Critical Errors Occlusal outline: I ______________________ yery wide (compromises cusp(s), marginal/transv.Ridges = -3 yery narrow (inadequate extension into grooves/anatomy = -2 Wide/narrow/irregular (Lack of Dovetail, deviates from j(circle) ideal etc. )= -1 Pulpal Depth: yery deep (compromises pulp) = -3 Deep (>lmm)/shallow (<lmm)/irreg = -1 j(circle) Extensions : I _______________ [crossly overextended (comprmises tooth structure) B/L = -3 Overextended (<lmm) B/L / underextended B/L = -1 kngle of departure (deviates from 90°) B/L = -1 l(circle) Axial wall: I ______________ yery deep (compromises pulp) = -3 Deep (>lmm) /shallow = -1 |Irreg/not parallel to external surface = -1 Gingival floor : yery deep (compromises tooth structure) = -3 Deep/shallow = -1 Irreg/rough = -1 (circle) 'Finnish : jWalls of prep not parallel (min=-. 5/max=-l) |Unf innished/rough (min=- . 5/max=-l) (circle) STUDENT #: ______________ LAB: GRADE: DATE :____________________ COMMENTS : 34 APPENDIX Bi UNIVERSITY OF SOUTHERN CALIFORNIA PRECLINICAL PEDIATRIC DENTISTRY LAB CAVIDRILL GRADE SHEET Exercise Critical errors Horizontal Too wide Too narrow "Nick” of outer line = Min "Breakthrough" (<lmm) = Max "Breakthrough" (>lmm) = Inner Line nor eliminated = -.5 -1 -2 -1 (circle) Multiple errors of the above (as indicated) Vertical Deep Minimally shallow (Islets of enamel) Very shallow (still in enamel) (circle) Internal considerations Parallelism Smoothness Minimal discrepancy Non paralel in part Totally non parallel Minimal roughness Greater roughness .5 1 2 .5 1 (circle) STUDENT # DATE : LAB: GRADE: COMMENTS : 35 APPENDIX G : P VALUES RESULTING FROM TEST OF NORMALITY OF THE SCORES RECEIVED FROM GRADER 1, GRADER 2, AND STRATIFIED BY GENDER (a = 0.0125) A. ALL STUDENTS: |G 1 MIDTERM EXAMINATION | FINAL EXAMINATION | |R 1 1 1 |0 1 1 1 1 |U 1 GRADER 1 GRADER 2| GRADER 1 1 GRADER 2 | |P 1 1 1 1 1 |1 1 0.02 0.07 1 0.42 1 0.05 1 |2 1 0.12 0.22 1 0.07 1 0.06 1 |3 1 0.23 0.003 1 0.06 1 0.05 1 14 1 0.04 0.03 1 0.03 1 0.18 1 B.FEMALE STUDENTS: |G 1 MIDTERM EXAMINATION | FINAL EXAMINATION | |R 1 1 1 |0 1 1 1 |U 1 GRADER 1 GRADER 2| GRADER 1 1 GRADER 2 | |P 1 1 1 1 |1 1 0.11 0.45 1 0.67 1 0.22 1 |2 1 0.11 0.07 1 0.30 1 0.68 1 |3 1 0.23 0.14 1 0.003 1 0.12 1 |4 1 0.81 0.006 1 0.09 1 0.04 1 C. MALE STUDENTS : |G 1 MIDTERM EXAMINATION I FINAL EXAMINATION | |R 1 1 1 |0 1 1 1 1 1 |U 1 GRADER 1 1 GRADER 2| GRADER 1 1 GRADER 2 | |P 1 1 1 1 1 1 1 1 1 1 1 |1 1 0.09 1 0.29 1 0.67 1 0.12 1 12 1 0.22 1 0.60 1 0.02 1 0.23 1 |3 1 0.06 1 0.09 1 0.05 1 0.05 1 |4 1 0.03 1 0.10 1 0.09 1 0.41 1 36 APPENDIX D FIGURE Dl: Box plots of Scores in Situations of Non-normality (All Students) Variable=Y(score) 5 + 4.5 + 4 + 3.5 + 3 + I I I + I I I + 2.5 1.5 GROUP GRADER PHASE +-----+ I I I I I I * _______* I + I I I I I +-----+ ■+ I I + + + + I I I I I ■+ * * I + I *____* I I I I I I +-----+ 0.5 + 0 - + + --+ + --------------- 37 APPENDIX D FIGURE D2 Box plots of Scores in Situations of Non-normality (Gender= Female) Phase 1 Variable=Y(score) 4.5 + I 4 + I I I 3.5 + I I 3 + I I I 2.5 + I I I 2 + 1.5 + I I I 1 + I I I 0.5 + I + I I I +-----+ GROUP GRADER PHASE GENDER 38 APPENDIX D FIGURE D3 Box plots of Scores in Situations of Non-normality (Gender= Female) Phase 2 Variable=Y(score) — — — + — 39 APPENDIX E SCORES OF CAVITY PREPARATIONS FROM CRADER 1, CRADER 2 AT MIDTERM AND FINAL EXAMINATION SUBJI CROUP I CENDER | MIDTERM FINAL # 1 1 11=FEMALE1------ I2=MALE 1CRADER 1 1 CRADER 2 1CRADER 1|CRADER 2 1 1 1 1.0 0.5 2.5 1.5 2 1 2 2.0 3.0 4.0 3.5 3 1 2 1.0 1.5 2.5 2.0 4 1 1 1.5 1.0 1.5 2.0 5 1 2 2.5 2.0 3.0 2.5 6 1 2 1.5 1.5 3.5 2.0 7 1 1 1.0 1.5 1.5 2.0 8 1 1 4.0 3.5 2.5 2.5 9 1 2 1.0 2.5 2.5 3.0 10 1 2 3.5 2.0 3.0 3.0 11 1 1 2.5 3.0 2.0 3.0 12 1 2 3.0 3.0 1.5 1.5 13 1 2 3.5 3.5 2.0 3.0 14 1 2 3.0 1.5 2.5 3.0 15 1 2 1.5 2.5 3.0 2.0 16 1 2 2.0 3.0 2.5 3.5 17 1 1 1.5 1.5 2.5 2.0 18 1 2 3.5 2.0 3.5 3.5 19 1 1 1.5 3.0 1.0 0.5 20 1 2 1.0 1.0 2.0 2.5 21 1 2 1.5 3.0 3.5 2.5 22 1 2 2.5 3.5 3.0 3.5 23 1 1 2.0 1.5 3.5 3.0 24 1 1 3.5 2.0 2.0 2.0 1 2 2 2.0 2.5 2.0 2.5 2 2 1 2.5 2.0 3.0 3.5 3 2 2 1.5 2.0 2.0 0.5 4 2 2 2.5 1.0 2.5 3.0 5 2 1 2.5 2.5 3.0 3.5 6 2 1 2.5 3.0 7 2 2 3.5 3.0 2.5 3.0 8 2 2 1.5 2.0 2.5 1.0 9 2 2 2.5 2.5 4.5 2.0 10 2 1 1.5 2.0 3.0 2.5 11 2 1 3.0 2.0 3.0 4.5 12 2 1 2.5 3.0 1.5 3.0 13 2 1 4.0 4.0 14 2 1 1.5 3.5 1.5 2.0 Note: missing values were entried as '. ' 40 APPENDIX E icon't) SCORES OF CAVITY PREPARATIONS FROM GRADER 1, GRADER 2 , AT MIDTERM AND FINAL EXAMINATION SUBJI GROUP I GENDER | MIDTERM | FINAL # I 11=FEMALEI----------------------------------------- I |2=MALE I GRADER 1 | GRADER 2 |GRADER 11GRADER 2 15 2 2 3.5 2.5 3.0 4.0 16 2 1 2.5 2.0 2.0 3.0 17 2 2 4.0 2.5 3.0 2.5 18 2 2 3.5 3.0 2.0 3.5 19 2 2 3.5 3.5 2.0 0.5 20 2 1 1.5 3.0 2.5 2.5 21 2 2 2.5 3.0 2.5 3.5 22 2 1 1.0 2.5 2.5 3.0 23 2 2 3.0 4.0 3.5 2.5 1 3 2 4.0 3.0 4.0 4.0 2 3 1 2.5 1.5 0.5 2.5 3 3 2 4.5 4.0 1.0 2.5 4 3 2 3.5 2.0 4.0 3.0 5 3 1 3.5 3.0 2.5 2.0 6 3 2 2.0 2.5 2.5 2.5 7 3 2 4.5 4.0 2.5 3.5 8 3 1 3.0 2.5 2.5 4.0 9 3 1 3.0 3.5 2.5 2.0 10 3 2 2.5 2.5 2.5 1.0 11 3 2 2.0 3.0 2.5 1.0 12 3 2 3.5 4.5 4.0 4.0 13 3 1 3.0 2.5 3.0 2.5 14 3 1 3.0 2.5 2.0 2.5 15 3 2 3.0 3.0 3.5 1.0 16 3 1 2.5 4.0 2.0 0.5 17 3 1 1.5 2.0 2.0 2.5 18 3 2 2.5 2.5 2.0 3.5 19 3 2 2.0 2.5 3.5 1.0 20 3 2 4.0 3.0 3.5 2.5 21 3 2 2.5 3.5 4.0 2.5 22 3 2 3.0 3.5 3.5 4.0 23 3 2 3.0 3.5 2.0 3.5 24 3 2 4.0 3.5 4.0 4.5 25 3 1 2.0 3.5 3.0 2.0 26 3 2 2.5 1.0 2.0 3.0 27 3 1 2.5 3.5 3.0 2.5 28 3 2 3.0 4.0 2.5 2.0 Note missing values were entried as 41 APPENDIX E (con't) SCORES OF CAVITY PREPARATIONS FROM GRADER 1, GRADER 2 AT MIDTERM AND FINAL EXAMINATION SUBJ1 GROUP 1 # 1 |1 1 |2 GENDER 1 MIDTERM 1 FINAL C AJrifLLiiJ 1---- =MALE 1 GRADER 1 1 GRADER 2 [GRADER 11 GRADER 2 29 3 1 3.5 4.0 2.5 3.0 30 3 2 3.0 3.5 3.0 2.5 31 3 2 1.5 2.5 2.5 1.5 32 3 1 3.0 3.5 3.0 3.5 33 3 2 1.5 1.5 0.5 1.0 34 3 2 3.0 3.5 2.5 3.5 35 3 2 2.5 3.5 2.5 4.0 36 3 1 2.0 3.5 3.0 2.0 37 3 2 2.0 2.0 38 3 2 4.0 2.5 2.5 2.0 39 3 2 4.0 4.0 3.5 3.0 40 3 2 4.0 3.5 4.5 3.5 41 3 2 4.0 2.5 3.0 3.5 42 3 2 2.5 3.5 2.5 2.0 43 3 2 3.0 3.0 3.5 3.0 44 3 2 2.0 2.5 3.5 2.5 1 4 2 2.5 3.0 2.5 2.5 2 4 1 1.5 2.5 2.0 2.0 3 4 2 1.5 2.5 1.5 1.5 4 4 2 4.0 3.5 2.5 3.5 5 4 1 0.5 2.5 2.0 2.0 6 4 2 1.5 1.5 2.5 2.0 7 4 1 4.0 3.5 3.0 3.5 8 4 2 1.0 0.5 3.0 3.0 9 4 2 3.5 3.5 3.5 2.5 10 4 2 2.0 1.5 1.5 4.0 11 4 2 1.5 2.5 1.0 2.5 12 4 2 1.5 1.0 2.5 1.5 13 4 2 2.5 3.0 1.0 2.0 14 4 2 2.5 3.0 3.0 4.0 15 4 2 4.5 2.5 3.5 3.0 16 4 1 1.5 2.5 3.0 2.0 17 4 1 2.0 2.5 3.0 3.5 18 4 2 1.5 2.0 2.0 3.5 19 4 2 2.0 1.5 3.5 4.5 20 4 1 3.0 3.0 3.5 4.0 21 4 2 1.0 3.0 1.5 1.5 22 4 2 1.5 2.0 3.0 2.5 23 4 2 2.0 3.0 3.5 3.0 24 4 2 3.0 3.0 2.0 3.0

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Asset Metadata

Creator Surjadi, Erna (author)

Core Title A comparison of training methods in cavity preparations in primary teeth for preclinical dental students

School Graduate School

Degree Master of Science

Degree Program Applied Biometry

Degree Conferral Date 1990-05

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag education,health and environmental sciences,OAI-PMH Harvest

Format application/pdf (imt)

Language English

Contributor Digitized by ProQuest (provenance)

Advisor Kipnis, Victor (committee chair), Azen, Stanley P. (committee member), Udin, Richard (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c37-197547

Unique identifier UC11649574

Identifier EP54929.pdf (filename),usctheses-c37-197547 (legacy record id)

Legacy Identifier EP54929.pdf

Dmrecord 197547

Document Type Thesis

Format application/pdf (imt)

Rights Surjadi, Erna

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the au...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus, Los Angeles, California 90089, USA