Reproducibility of a Digital Method to Evaluate Soft Tissue Modifications: A study of Inter and Intra-Operative Measurement Concordance

Influence of Angulation in Cervical Prosthetic Emergences Relative to the Gingival Tissue of Teeth Treated under the Biologically Oriented Preparation Technique (BOPT)

Background: The objective of this study was to digitally evaluate the effect of the cervical emergence of restorations in terms of gingival tissue volume. Materials and methods: In this study, 31 upper front teeth (from canine to canine) were selected and prepared using the biologically oriented preparation technique (BOPT). Each tooth had undergone a change in its provisional process with different emergence profile angles: 30° and 60°. Each sample was digitalised (STL file) using an intraoral scanner. By using various pieces of manipulation software for STL files, a volumetric analysis protocol was carried out. Changes in gingival thickness and position were measured at the buccal and the lingual positions. Results: By increasing the angulation of the emergence profile to 60°, the gingival thickness increased by 0.255 ± 0.381 mm (p = 0.001; t-test) at buccal and by 0.038 ± 0.381 mm at lingual (p = 0.600; t-test). In relation to the gingival height, at buccal, there is an apical displacement of 0.262 ± 0.246 mm (p = 0.001; t-test), and at lingual, there is an apical displacement of 0.390 ± 0.279 mm (p = 0.001; t-test). It was shown that an increase in the provisional emergence profile angle significantly diminishes the gingival height while significantly increasing gingival thickness. The Pearson’s correlation coefficient, r = 0.636, was moderately high and significant (p = 0.001; Pearson). Conclusions: The soft tissue surrounding the BOPT restored tooth evolved according to the prosthetic emergence angle of the provisional restoration, enabling us to plan for an apico-coronal and bucco-lingual displacement of the gingival tissue prior to the definitive restoration.

3D Digital Impression Systems Compared with Traditional Techniques in Dentistry: A Recent Data Systematic Review

The advent of new technologies in the field of medicine and dentistry is giving improvements that lead the clinicians to have materials and procedures able to improve patients' quality of life. In dentistry, the last digital techniques offer a fully digital computerized workflow that does not include the standard multiple traditional phases. The purpose of this study is to evaluate all clinical trials and clinical randomized trials related to the digital or dental impression technique in prosthetic dentistry trying to give the readers global information about advantages and disadvantages of each procedure. Data collection was conducted in the main scientific search engines, including articles from the last 10 years, in order to obtain results that do not concern obsolete impression techniques. Elsevier, Pubmed and Embase have been screened as sources for performing the research. The results data demonstrated how the working time appears to be improved with digital workflow, but without a significant result (P = 0.72596). The papers have been selected following the Population Intervention Comparison Outcome (PICO) question, which is related to the progress on dental impression materials and technique. The comparison between dentists or practitioners with respect to classic impression procedures, and students open to new device and digital techniques seem to be the key factor on the final impression technique choice. Surely, digital techniques will end up supplanting the analogical ones altogether, improving the quality of oral rehabilitations, the economics of dental practice and also the perception by our patients.

Reliability of a Virtual Prosthodontic Project Realized through a 2D and 3D Photographic Acquisition: An Experimental Study on the Accuracy of Different Digital Systems

AIMS

The study aims to assess the accuracy of digital planning in dentistry, evaluating the characteristics of different intraoral 3D scanners and comparing it with traditional imaging 2D recording methods. Specifically, using computer aided design (CAD) software and measuring inside CAD software, authors want to verify the reliability of different models obtained with different techniques and machines.

METHODS

12 patients that needed aesthetic restorative treatment were enrolled in the study. All the patients underwent recording data of the height and width dental elements 1.1, 1.2, and 1.3 size using different technologies and comparing 2D with 3D methods. A T test was then applied in order to verify whether there was a statistically significant difference between the measurements obtained, comparing the different tools data (Emerald, TRIOS, Photogrammetry and DSS (Digital Smile System)) with the reference values.

RESULTS

No significant differences emerged in the measurements made with the different scanners (Trios 3Shape ®, Planmeca Emerald ®) and photogrammetry. Therefore, what should be underlined regarding the 2D measurements is the speed and simplicity compared to all 3D techniques, so this work can help to better define the field of application and the limits connected to 2D techniques, giving a good window of the technique.

CONCLUSIONS

The low number of patients is not sufficient to provide statistically significant results, but the digital planning future prospects seem to be promising. This study results highlighted how a photogrammetric scanner for dental arches would only have a much smaller shooting field size and greater accuracy. Despite these considerations, the photogrammetric facial scanner provided excellent results for the measurement of individual teeth, showing a great versatility of use.

The accuracy and reliability of digital measurements of gingival recession versus conventional methods

BACKGROUND

An apical shift in the position of the gingiva beyond the cemento-enamel junction leads to gingival recession. This study aimed to evaluate the reproducibility of digital measurements of gingival recession when compared to conventional measurements taken clinically using periodontal probes.

METHODS

Gingival recession was measured at 97 sites in the oral cavity by four examiners using the following methods: CP, direct measurement of gingival recession using William's periodontal probe intraorally; CC, measurements on cast models using a caliper; DP, digital measurement on virtual models obtained by intraoral scanning, and DC, digital measurements on virtual models of dental casts. Intra-class and inter-rater correlations were analyzed. Bland Altman plots were drawn to visually determine the magnitude of differences in any given pair-wise measurements.

RESULTS

In this study, good inter-methods reliability was observed for almost all the examiners ranging from 0.907 to 0.918, except for one examiner (0.837). The greatest disagreements between the raters were observed for methods; CP (0.631) followed by CC (0.85), while the best agreements were observed for methods DP (0.9) followed by DC (0.872).

CONCLUSION

Variations in measurements between examiners can be reduced by using digital technologies when compared to conventional methods. Improved reproducibility of measurements obtained via intraoral scanning will increase the validity and reliability of future studies that compare different treatment modalities for root coverage.