A Formula for Success © 3M 2008. All Rights Reserved. Evaluation of the Clinical Performance of the...

A Formula for Success

© 3M 2008. All Rights Reserved.

Evaluation of the Clinical Performance of the Lava™ Chairside Oral Scanner C.O.S.


Objectives of the Lava C.O.S. Clinical Study

Evaluation of the marginal fit of Lava all-ceramic crowns generated from 2-step impressions versus Lava C.O.S. scans by means of a replica technique (Fit Checker)

Evaluation of the marginal, occlusal and interproximal fit of Lava all-ceramic crowns generated from 2-step impressions versus Lava C.O.S. scans by 2 calibrated and blinded examiners

Evaluation of operator comfort Evaluation of patient comfort


Materials and Methods IRB / EC approval from freiburger ethik-kommission international (code 08/2218)

and 3M IRB (St. Paul, MN, code 08-95) 20 patients enrolled (male and female) Patients inclusion criteria

employed at 3M ESPE between 18 und 65 years in the need of a single crown at posterior teeth study tooth free of clinical symptoms no need for additional extended treatment (e.g. endodontic treatment) maintain an acceptable standard of oral hygiene have given informed consent

Patients exclusion criteria advanced periodontitis (tooth mobility higher than 2) pressing, clenching, grinding patients pregnant or lactating females medical or dental history which could possibly complicate the provision of the

proposed restorations and/or influence the behaviour and performance of the restorations in clinical service.


Impression material and technique: Express™2 Penta Putty / Express™2 Ultra-Light Body Quick in a 2-step technique (

Materials and Methods (continued)


Lava Chairside Oral Scanner C.O.S.




Express 2 Ultra-Light Body Quick as Fit Checker Express 2 Light-Body Flow Quick to stabilize Fit Checker Sections in mesio-distal and bucco-lingual direction 3 Fit Checkers per coping (6 per patient); adapted with finger pressure for 3 s Stereomikroskop Stemi SVII von Zeiss Magnification 66X Film thickness measurement at mesial, distal, buccal, lingual side


Marginal contour criteria according to „Studienhandbuch Qualitätssicherung in der Zahnmedizin - Kriterien für die Prothetik. Würzburg , 1988.

Calibrated probes with 50µm, 150 µm, 250 µm tip diameter (Deppeler, CH) 2 blinded examiners (dentists) Forced consensus Evaluation of the mesial, distal, buccal and lingual surface




Ratings for interproximal contact points:

1. Clinically excellent: normal contact point; dental floss can be easily inserted.2. Clinically good: contact slightly too strong, but dental floss can still be inserted.3. Clinically unsatisfactory: contact too strong so that dental floss cannot be inserted or contact

too weak with food impaction likely to occur. 4. Clinically poor: no contact point or papilla damage or crown cannot be seated

Quality ratings for occlusion:

1. Clinically excellent: occlusal contact points on the crown and adjacent teeth, equally strong; no supra- or infraoclusion

2. Clinically good: occlusal contact points on the crown and adjacent teeth, but unequally strong; no supra- or infraoclusion

3. Clinically unsatisfactory: no occlusal contact points on the crown (infraocclusion)

4. Clinically poor: contact points only on the crown (crown too high = supraocclusion)


Results

N=216 (4 surfaces x 3 fit checkers x 18 patients) Normality Test, Levene´s Test, Mann-Whitney-Test p<0,05


Results (continued)


Evaluation of Practitioner Comfort


Evaluation of Patient Comfort


Conclusions from the Fit Checker Analysis

All ceramic crowns resulting from Lava C.O.S. scans showed significantly better marginal fit than all-ceramic crowns resulting from 2-step impressions.

Both groups revealed marginal gaps that are clinically acceptable. Compared with marginal gaps reported in the clinical literature

(ranging from 50-1424 µm) the marginal fit of crowns in both study groups was excellent.


Conclusions from the Clinical Crown Assessments

There was a clear trend towards better marginal quality for crowns generated from Lava C.O.S. scans, which can be explained by the fact that in the Lava C.O.S. group the Zirkonia copings were designed directly from the Lava C.O.S. scan data, while in the conventional impression group first a gypsum model was created, which was then scanned as the basis for the Zirkonia coping.

The interproximal contact quality was better in the Lava C.O.S. group compared to the control group.

There was no difference in the occlusal quality between the two groups.

If marginal gaps occured, they were below 150 µm, which is considered to be clinically acceptable.


Digital Workflow - The Future is Now!Lava™ Precision Solutions from Lava C.O.S. to Lava DVS:

3M ESPE end-to-end digital solution from intra-oral data to full restauration - a case report

Dr. Dr. A. Syrek

CDT T. Hiebel

CDT W. Borgmann

Pictures Dr. E. Mecher


Lava Chairside Oral Scanner C.O.S.


Protemp™ Crown Temporization Material


Lava C.O.S. Lab Software


SLA Model


SLA Model with Lava Crown


RelyX™ Unicem Self-Adhesive Universal Resin CementElipar™ S10 LED Curing Light


…to digital dentistry? YES WE CAN!YES WE SCAN!

http://riflesready.files.wordpress.com/2008/11/barack_obama_change_fairey.jpg


Acknowledgements

Dr. Gunnar Reich, General Dental Practitioner from MunichDoortje Jäckel, Dental Hygienist and AssistantDr. Jutta Brodesser, Clinical ExaminerDr. Barbara Cerny, Clinical ExaminerDieter Ranftl, Statistician

Special Thank You toChristoph Klein, Student from Dental Material College in Osnabrück

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