Ignite Creation Date:
2024-05-06 @ 1:19 PM
Last Modification Date:
2024-10-26 @ 1:12 PM
Study NCT ID:
NCT03992300
Status:
COMPLETED
Last Update Posted:
2019-12-16
First Post:
2019-06-17
Brief Title:
Comparison of Full-arch Implant-supported Frameworks From an Intraoral Scanning or From a Conventional Impression
Sponsor:
Universitat Internacional de Catalunya
Organization:
Universitat Internacional de Catalunya
Study Overview
Official Title:
Comparison of Accuracy and Timing Parameter of Digital and Conventional Impression Techniques on Fully Edentulous Jaws an in Vivo Study
Status:
COMPLETED
Status Verified Date:
2019-06
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Purpose To determine if adjustment of full-arch zirconia frameworks processed on a model obtained with an intraoral scanner and an auxiliary device is not inferior to that of identical frameworks obtained from an elastomeric impression
Materials and methods Eight consecutive patients ready for a full-arch rehabilitation on already osseointegrated implants were selected Two sets of impressions were taken one open tray with polyether and splinted impression copings and a second one with an intraoral scanner A verification plaster jig was used for the elastomeric impression and a prefabricated auxiliary device was used to adjust the optical intraoral impressions Two full-zirconia frameworks with the same design were processed and tested on the patient by two independent calibrated operators Accuracy of both frameworks was measured by calibrated blinded operators who determined tactile adjustment Sheffield test radiographic adjustment and screwing torque Overall perception of adjustment was used to determine the better framework to be delivered to the patient
Hº Frameworks obtained from an impression taken with an intraoral scanner are not inferior in accuracy to those obtained from a conventional elastomeric impression
Materials and methods Eight consecutive patients ready for a full-arch rehabilitation on already osseointegrated implants were selected Two sets of impressions were taken one open tray with polyether and splinted impression copings and a second one with an intraoral scanner A verification plaster jig was used for the elastomeric impression and a prefabricated auxiliary device was used to adjust the optical intraoral impressions Two full-zirconia frameworks with the same design were processed and tested on the patient by two independent calibrated operators Accuracy of both frameworks was measured by calibrated blinded operators who determined tactile adjustment Sheffield test radiographic adjustment and screwing torque Overall perception of adjustment was used to determine the better framework to be delivered to the patient
Hº Frameworks obtained from an impression taken with an intraoral scanner are not inferior in accuracy to those obtained from a conventional elastomeric impression
Detailed Description:
Eight consecutive patients ready for a full-arch rehabilitation on previously osseointegrated implants and who had received an immediately loaded prosthesis were selected All implants had multiunit abutments placed on top Cases from 4 to 6 implants were accepted either upper or lower arches Three sets of impressions were taken to each patient
Conventional impression
Open tray impression copings were screwed on top of all implants in the arch using a torque wrench set at 10 Ncm Impression copings were splinted by means of Triad Gel clear resin with an at least 3mm diameter in the resin connectors Once the resin was photo-polymerized a cut was done in the centre of each connection with a 03 mm bur to eliminate possible stress in the structure and then it was splinted again with a drop of Triad Gel in each cut A polyether impression was taken by means of a perforated plastic tray and a master model was fabricated following the manufacturers instructions A plaster verification jig was fabricated on the model After one week the patient came to the dental clinic where vertical dimension of occlusion was determined and the plaster key was screwed in the patient mouth to check passivity In case the key had been fractured a new impression would have been taken and if not final prosthesis could be processed
Optical impression
An impression of the antagonist and an impression of the edentulous arch with the healing abutments in place were taken by means of an optical scanner following the manufacturers protocol The position of the implants was marked in the working standard tessellation language STL model and the software cut a circle on top of those areas The files were copied and two datasets were obtained
Scan-bodies were placed on top of each multiunit abutment the first STL dataset was open and a second impression was taken so that the scan-bodies were positioned on the working file
Scan-bodies were then removed from the patient mouth and temporary copings were placed on top of each multiunit abutment A MedicalFit device was selected and holes were drilled in the position of the implants until it fitted on top of all the cylinders Cylinders were then splinted to MedicalFit device by means of Triad Gel clear The device was then removed from the patient mouth and scan implant replicas were placed at the bottom of the metal cylinders Finally the device with the scan implant replicas was scanned with an intraoral optical scanner
The following set of pictures were taken Rest position maximum smile with the scan bodies placed in the mouth front with retractors with the scan bodies and 45º with retractors also with the scan bodies in place
All pictures and STL datasets were sent to the dental technician to produce a temporary structure The STL dataset from the scanning of Medicalfit device used was adjusted to the original STL dataset of the device in the library and then superimposed to the dataset of the scan-bodies received from us to allow repositioning of the scan-bodies and to correct possible discrepancies during the intraoral scanning process
A temporary polymethylmethacrylate PMMA framework was delivered by the dental lab and tried in the patient mouth Corrections were done to adjust occlusion gingival contour and esthetic parameters where needed Once esthetic parameters and occlusal scheme were considered correct a new intraoral scanning was taken with the temporary framework in place In case changes were done in the gingival contour scanning of the gingival aspect of the PMMA framework was also done The PMMA temporary was then left in the patient mouth
Three pictures were taken with the PMMA framework placed in the mouth Front full face at rest front full-face smiling front full face with separators and full face smiling at 45º
Clinical adjustment assessment
After one week two sets of the final prosthesis in full-zirconia were sent from the dental lab one processed with conventional models and the second fully digital Both sets were tested in the patient mouth by two calibrated blinded independent operators
Misfit should be ideally measured in terms smaller than 10 microns but clinical adjustment is difficult to assess using conventional or quantitative methods In this research adjustment was assessed following four criteria passivity in the insertion of the screws tactile sensation radiographs and screwing torque
1 A Visual Analogue Scale VAS was used to assess the perception of passivity in the insertion of the prosthodontic screws A ten centimeters line will be shown to the observer One side of the line represents perfect passivity and the other no passive at all The observer will mark his passivity perception on the line between the two endpoints The distance between no passivity at all and the mark will defines the passivity perception
2 Examination of the marginal fit with an exploratory probe 233 explorer under 38x magnification Three possible scores were possible 0 no gap perceived when probing 1 perception of the gap without entering it and 2 the tip of the explorer clearly entered the gap
3 Periapical radiographs were taken with a positioning system to evaluate possible gaps Five possible scores were possible from 1 to 5 being 1 no gap and increasing 015 mm each score until reaching 060 mm in score 5
4 Digital photographs were taken with a 105 mm macro lens The pictures were calibrated with the known height of the framework and the gap was measured Four possible scores were possible being 1 no gap and increasing 025 mm each score until reaching 075 mm in score 5
5 Screwing torque on each abutment was measured with the app software from Ichiropro motor BienAir Bienne Switzerland All screws were hand screwed and then all but the most distal right were unscrewed Torque was set at 15 Ncm and speed at 5 rpm The most right distal screw was tightened first and then the rest of the screws were tightened starting at the most mesial left following to the most distal left and from that to the next neighbor implant until all screws were tightened The torque-time signature was studied in every screw to determine if the torque started to grow just at the end of the tightening or throughout the process Three scores were possible 1 for linear value with a fast increase at end of the tightening 2 for soft continuous growth with a steeper increase at the end 3 for steep increase at the beginning of tightening
Once the assessment of the two frameworks was completed the framework with better adjustment will be placed in the patient after assessing the presence of correct occlusion phonetics and esthetic parameters The second set will be packed and delivered to the patient as a possible replacement in case of problems in the future
Conventional impression
Open tray impression copings were screwed on top of all implants in the arch using a torque wrench set at 10 Ncm Impression copings were splinted by means of Triad Gel clear resin with an at least 3mm diameter in the resin connectors Once the resin was photo-polymerized a cut was done in the centre of each connection with a 03 mm bur to eliminate possible stress in the structure and then it was splinted again with a drop of Triad Gel in each cut A polyether impression was taken by means of a perforated plastic tray and a master model was fabricated following the manufacturers instructions A plaster verification jig was fabricated on the model After one week the patient came to the dental clinic where vertical dimension of occlusion was determined and the plaster key was screwed in the patient mouth to check passivity In case the key had been fractured a new impression would have been taken and if not final prosthesis could be processed
Optical impression
An impression of the antagonist and an impression of the edentulous arch with the healing abutments in place were taken by means of an optical scanner following the manufacturers protocol The position of the implants was marked in the working standard tessellation language STL model and the software cut a circle on top of those areas The files were copied and two datasets were obtained
Scan-bodies were placed on top of each multiunit abutment the first STL dataset was open and a second impression was taken so that the scan-bodies were positioned on the working file
Scan-bodies were then removed from the patient mouth and temporary copings were placed on top of each multiunit abutment A MedicalFit device was selected and holes were drilled in the position of the implants until it fitted on top of all the cylinders Cylinders were then splinted to MedicalFit device by means of Triad Gel clear The device was then removed from the patient mouth and scan implant replicas were placed at the bottom of the metal cylinders Finally the device with the scan implant replicas was scanned with an intraoral optical scanner
The following set of pictures were taken Rest position maximum smile with the scan bodies placed in the mouth front with retractors with the scan bodies and 45º with retractors also with the scan bodies in place
All pictures and STL datasets were sent to the dental technician to produce a temporary structure The STL dataset from the scanning of Medicalfit device used was adjusted to the original STL dataset of the device in the library and then superimposed to the dataset of the scan-bodies received from us to allow repositioning of the scan-bodies and to correct possible discrepancies during the intraoral scanning process
A temporary polymethylmethacrylate PMMA framework was delivered by the dental lab and tried in the patient mouth Corrections were done to adjust occlusion gingival contour and esthetic parameters where needed Once esthetic parameters and occlusal scheme were considered correct a new intraoral scanning was taken with the temporary framework in place In case changes were done in the gingival contour scanning of the gingival aspect of the PMMA framework was also done The PMMA temporary was then left in the patient mouth
Three pictures were taken with the PMMA framework placed in the mouth Front full face at rest front full-face smiling front full face with separators and full face smiling at 45º
Clinical adjustment assessment
After one week two sets of the final prosthesis in full-zirconia were sent from the dental lab one processed with conventional models and the second fully digital Both sets were tested in the patient mouth by two calibrated blinded independent operators
Misfit should be ideally measured in terms smaller than 10 microns but clinical adjustment is difficult to assess using conventional or quantitative methods In this research adjustment was assessed following four criteria passivity in the insertion of the screws tactile sensation radiographs and screwing torque
1 A Visual Analogue Scale VAS was used to assess the perception of passivity in the insertion of the prosthodontic screws A ten centimeters line will be shown to the observer One side of the line represents perfect passivity and the other no passive at all The observer will mark his passivity perception on the line between the two endpoints The distance between no passivity at all and the mark will defines the passivity perception
2 Examination of the marginal fit with an exploratory probe 233 explorer under 38x magnification Three possible scores were possible 0 no gap perceived when probing 1 perception of the gap without entering it and 2 the tip of the explorer clearly entered the gap
3 Periapical radiographs were taken with a positioning system to evaluate possible gaps Five possible scores were possible from 1 to 5 being 1 no gap and increasing 015 mm each score until reaching 060 mm in score 5
4 Digital photographs were taken with a 105 mm macro lens The pictures were calibrated with the known height of the framework and the gap was measured Four possible scores were possible being 1 no gap and increasing 025 mm each score until reaching 075 mm in score 5
5 Screwing torque on each abutment was measured with the app software from Ichiropro motor BienAir Bienne Switzerland All screws were hand screwed and then all but the most distal right were unscrewed Torque was set at 15 Ncm and speed at 5 rpm The most right distal screw was tightened first and then the rest of the screws were tightened starting at the most mesial left following to the most distal left and from that to the next neighbor implant until all screws were tightened The torque-time signature was studied in every screw to determine if the torque started to grow just at the end of the tightening or throughout the process Three scores were possible 1 for linear value with a fast increase at end of the tightening 2 for soft continuous growth with a steeper increase at the end 3 for steep increase at the beginning of tightening
Once the assessment of the two frameworks was completed the framework with better adjustment will be placed in the patient after assessing the presence of correct occlusion phonetics and esthetic parameters The second set will be packed and delivered to the patient as a possible replacement in case of problems in the future
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None