Conventional and digital impressions for complete-arch implant-supported fixed prostheses: time, implant quantity effect and patient satisfaction.

PURPOSE To evaluate and compare the effect of impression type (conventional vs digital) and the number of implants on the time from the impressions to the generation of working casts of mandibular implant-supported fixed complete-arch frameworks, as well as on patient satisfaction. MATERIALS AND METHODS 17 participants, 3 or 4 implants, received 2 types of digital impression methods (DI) and conventional (CI). In DI, two techniques were performed: scanning with the scan bodies (SC) and scanning with a device attached to the scan bodies (SD) (BR 10 2019 026265 6). In CI, the making of a solid index (SI) and open-tray impression (OT) were used. The outcomes were used to evaluate the time and the participant satisfaction with conventional and digital impressions. The time was evaluated through the timing of the time obtained in the workflow in the conventional and digital impression. The effect of the number of implants on time was also assessed. Satisfaction was assessed through a questionnaire based on seven. The Wilcoxon test used to identify the statistical difference between the groups in terms of time. The Mann-Whitney test was used to analyze the relationship between the time and the number of implants. Fisher's test was used to assess the patient satisfaction (P < .05). RESULTS The time with DI was shorter than with CI (DI, x̃=02:58; CI, x̃=31:48) (P < .0001). The arches rehabilitated with 3 implants required shorter digital impression time (3: x̃=05:36; 4: x̃=09:16) (P < .0001). Regarding satisfaction, the DI was more comfortable and pain-free than the CI (P < .005). CONCLUSION Digital impressions required shorter chair time and had higher patient acceptance than conventional impressions

Impact of residual ridge anatomy on masticatory efficiency of conventional complete denture users

ABSTRACT Objective: The aim of this cross-sectional study was to evaluate the anatomical characteristics of edentulous residual ridges in stone casts of complete dentures users and assess correlations with masticatory efficiency. Methods: The sample included 74 study casts, of which 37 were higher and 37 bottom. Measurements were performed using a drypoint compass and a transparent ruler. Arches and ridges of maxillae and mandibles were classified into small, medium, and large. Masticatory efficiency was obtained by the sieve method with the old prostheses and 3 months after placement of new prostheses. The correlations between the anatomical variables of the ridges and arches (height, width and size) and masticatory efficiency were verified by the Spearman correlation test. Significant differences in masticatory efficiencies were assessed by the Wilcoxon test. Results: People with larger maxillary alveolar ridge presented better masticatory performance with old and new dentures. There was no correlation between maxillary ridge width and size with masticatory efficiency, but a correlation was found between maxillary arch width and masticatory efficiency evaluated with the old dentures. Conclusions: With the new dentures, the correlation had a tendency for significance. For the mandible, no correlation was found between height, width, and size of the ridge or with width, length, and size of the arch and masticatory efficiency. In addition, there was no significant difference between masticatory efficiencies evaluated with the old and new prostheses. For the maxilla, ridge height and arch width influence masticatory efficiency. For the mandible, the anatomy had little influence on masticatory performance

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved