Transcript Lava COS Scientific Facts Evaluation of Clinical Performance

A Formula for Success
Evaluation of the Clinical
Performance of the Lava™
Chairside Oral Scanner C.O.S.
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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
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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
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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
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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.
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Materials and Methods (continued)
Impression material and technique: Express™2 Penta Putty /
Express™2 Ultra-Light Body Quick in a 2-step technique (
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Materials and Methods (continued)
Lava Chairside Oral Scanner C.O.S.
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Materials and Methods (continued)
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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
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Materials and Methods (continued)
 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
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Materials and Methods (continued)
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)
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Results
 N=216 (4 surfaces x 3 fit checkers x 18 patients)
 Normality Test, Levene´s Test, Mann-Whitney-Test p<0,05
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Results (continued)
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Results (continued)
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Evaluation of Practitioner Comfort
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Evaluation of Patient Comfort
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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.
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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.
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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
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Lava Chairside Oral Scanner C.O.S.
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Lava Chairside Oral Scanner C.O.S.
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Protemp™ Crown Temporization Material
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Lava C.O.S. Lab Software
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SLA Model
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SLA Model with Lava Crown
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RelyX™ Unicem Self-Adhesive Universal Resin Cement
Elipar™ S10 LED Curing Light
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…to digital dentistry?
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YES WE SCAN!
CAN!
Acknowledgements
Dr. Gunnar Reich, General Dental Practitioner from Munich
Doortje Jäckel, Dental Hygienist and Assistant
Dr. Jutta Brodesser, Clinical Examiner
Dr. Barbara Cerny, Clinical Examiner
Dieter Ranftl, Statistician
Special Thank You to
Christoph Klein, Student from Dental Material College in Osnabrück
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