Masticatory Efficiency in Implant-Supported Fixed Complete Dentures Compared with Conventional Dentures: A Randomized Clinical Trial by Color-Mixing Analysis Test.

PURPOSE: To compare the masticatory efficiency of an All-on-4 prosthesis with complete dentures on a Class I ridge with a color-mixing analysis test. MATERIALS AND METHODS: Ten patients with fixed complete dentures on implants and an additional 10 patients with conventional complete dentures on a Class I ridge (Atwood) chewed a bicolor chewing gum (Hubba Bubba) for different numbers of cycles (5, 10, 15, and 20). The chewed gum was retrieved, scanned, and weighted to quantify masticatory efficiency. RESULTS: This study showed higher values for implant-supported fixed complete dentures than conventional complete dentures. These findings were significant with the color-mixing test in cycles 5 and 10 between both groups. The reduction in weight was not significantly different between the two groups but was noteworthy in intercycle comparison. CONCLUSION: Implant-supported fixed complete dentures showed superior masticatory efficiency compared with conventional complete dentures constructed over well-formed ridges in the early chewing cycles.

Reproducibility of wax interocclusal records on different articulators.

CONTEXT: The construction of a dental prosthesis needs the duplication of intermaxillary relationships of the patient on the articulator. This procedure is normally fulfilled using interocclusal records to program the articulator according to the patient's condylar inclinations. Wax is a popular recording material used for this purpose but has proven to suffer from inaccuracies due to its dimensional variation over time. AIMS: This study intends to test the reproducibility of eccentric interocclusal wax records over time. SETTING AND DESIGN: Thirteen dental students aged between 18 and 30 years participated in this study. Maxillary and mandibular casts of the participants were mounted on two types of articulators; wax lateral and protrusive interocclusal records were used to program these articulators. SUBJECTS AND METHODS: Horizontal and lateral condylar inclinations were obtained for each participant. The interocclusal records were stored for 10 days and the casts of each participant were remounted on the articulators. The interocclusal records were reused to obtain new condylar inclinations of each participant. The initial and the delayed condylar inclinations were compared to evaluate the impact of storage time on wax records. STATISTICAL ANALYSIS USED: Paired Student's t-test was used for this comparison. RESULTS: No significant difference (0.38 < P < 0.92) was found between initial and delayed condylar inclinations for both articulators. An interclass correlation coefficient analysis was used to test the reproducibility of measures, and the correlation was significantly elevated (intraclass correlation coefficient >0.600). CONCLUSIONS: The use of wax interocclusal records for articulator programing was shown to be acceptable even with delayed intervals, without concerns of possible variations of condylar settings due to storage time.