Purpose: To demonstrate how data collected using the computerized planimetric method (CPM) can be analyzed by providing an example in which the amount of plaque accumulation and the efficacy of the rotating needles device (RND) in cleaning specific parts of partial removable dental prostheses (PRDPs) were estimated. Materials and Methods: Thirty-four participants wearing a total of 41 double-crown-retained PRDPs with veneered secondary crowns were included in this study. The PRDPs underwent the following steps: preparing the PRDP for photography, photography of the PRDP, cleaning the PRDP with the RND, and re-photography. One trained examiner used a tested CPM to analyze 98 images (49 before/49 after). Each participant was considered as a statistical unit; thus, if the participant had two PRDPs, one was randomly selected for analysis. Results: The intraclass correlation coefficients (images before/after) for both the base and veneer were > 0.9. Wilcoxon signed rank test P value was .001 for the comparison of plaque accumulation on the base and veneer, estimating the RND's efficacy on both PRDP parts (before/after) and comparing the RND's efficacy on the base and the RND's efficacy on the veneer. Conclusion: There are different ways to analyze data collected via CPM; thus, it is advisable to provide an explanation for the choice of modeling. Plaque accumulation was significantly greater on the double-crown veneer than on the base. The RND efficacy in cleaning the veneer and the base is significant, but more substantial in cleaning the base.