Mechanical performance of posterior Implant supported Crowns using abutments with different angulations
Samar Saeed Taha Bedair;
Abstract
Dental implants have become a significant aspect of tooth replacement in prosthodontic treatment.Despite of high success rates, complications and failures still occur.
The anatomic configuration of the osseous structures may dictate placement of implants, and the position and angulations of the teeth adjacent to the edentulous space must also be considered. Angulated abutments may be used to overcome non-ideal implant location due to lack of bone.
Using angulated abutments with different types of restorative materials to construct the overlying fixed partial dentures are significant factors in determining the amount and distribution of the stresses loaded onto the superstructure and implant under functional forces.
Therefore, the aim of the current study was to evaluate strain applied on zirconia and metal fixed partial dentures constructed over different abutment angulations straight, 15° and 25° abutments.
Thirty implant analogs were chosen to replicate posterior first premolar and first molar and were embedded in supportive resin. Then mounted by thirty abutments 10 straight, 10 15° and 10 25° angled.
A digital impression was performed for theabutments as they were scanned by the use of IdenticaBlue Desktop Scanner that, then will import the image taken to the CAD software the ExoCad.Five full contoured bridges according to anatomical aspectswere designed on the scanned abutments for each abutment angulations (straight, 150 angled,250 angled) using ExoCad software.As the restoration was designed and was shown exactly as it will be machined by the milling unit,milling machine is VHF CAM5 S1. Any final fine adjustments were made in this step. This was done for the first group; zirconia.
VIPI BLOCK WAX wasused for milling of the same design used with the zirconia restorations. This material allows the reduction in milling times and easy extraction and was ideal for casting andinjection process.Then, milling of the wax to desired restoration that was afterwards casted into metal restoration.
The cast frameworks were then sandblasted to remove the remaining investment material.
The results of strain showed that the higher the implant angulations, the higher the strain developed.
The results of strain showed that angled abutment had statistically significant higher strain transmitted to implant on mesial and distal sides
While the zirconia fixed partial dentures had statistically higher strain transmitted to implant than metal.
Conclusions:
Under the limitation of this study, several conclusions could be drawn:
1. Metal superstructureproduced less strain than Zirconia superstructures to implant.
2. Increasing the abutment angulations to 25° increases the strain transferred to implant body.
Recommendations:
1. Placement of implant parallel to long axis is recommended than angulated placement, as this decreases the strain applied on the implant, as the angle increases the produced strain increases.
2. It is better to use metal rather than Zirconia as implant superstructure.
3. Further investigations can be employed to asses other materials to be used as suprastructures to implants as a restorative material.
The anatomic configuration of the osseous structures may dictate placement of implants, and the position and angulations of the teeth adjacent to the edentulous space must also be considered. Angulated abutments may be used to overcome non-ideal implant location due to lack of bone.
Using angulated abutments with different types of restorative materials to construct the overlying fixed partial dentures are significant factors in determining the amount and distribution of the stresses loaded onto the superstructure and implant under functional forces.
Therefore, the aim of the current study was to evaluate strain applied on zirconia and metal fixed partial dentures constructed over different abutment angulations straight, 15° and 25° abutments.
Thirty implant analogs were chosen to replicate posterior first premolar and first molar and were embedded in supportive resin. Then mounted by thirty abutments 10 straight, 10 15° and 10 25° angled.
A digital impression was performed for theabutments as they were scanned by the use of IdenticaBlue Desktop Scanner that, then will import the image taken to the CAD software the ExoCad.Five full contoured bridges according to anatomical aspectswere designed on the scanned abutments for each abutment angulations (straight, 150 angled,250 angled) using ExoCad software.As the restoration was designed and was shown exactly as it will be machined by the milling unit,milling machine is VHF CAM5 S1. Any final fine adjustments were made in this step. This was done for the first group; zirconia.
VIPI BLOCK WAX wasused for milling of the same design used with the zirconia restorations. This material allows the reduction in milling times and easy extraction and was ideal for casting andinjection process.Then, milling of the wax to desired restoration that was afterwards casted into metal restoration.
The cast frameworks were then sandblasted to remove the remaining investment material.
The results of strain showed that the higher the implant angulations, the higher the strain developed.
The results of strain showed that angled abutment had statistically significant higher strain transmitted to implant on mesial and distal sides
While the zirconia fixed partial dentures had statistically higher strain transmitted to implant than metal.
Conclusions:
Under the limitation of this study, several conclusions could be drawn:
1. Metal superstructureproduced less strain than Zirconia superstructures to implant.
2. Increasing the abutment angulations to 25° increases the strain transferred to implant body.
Recommendations:
1. Placement of implant parallel to long axis is recommended than angulated placement, as this decreases the strain applied on the implant, as the angle increases the produced strain increases.
2. It is better to use metal rather than Zirconia as implant superstructure.
3. Further investigations can be employed to asses other materials to be used as suprastructures to implants as a restorative material.
Other data
| Title | Mechanical performance of posterior Implant supported Crowns using abutments with different angulations | Other Titles | الاداء الميكانيكي للغرسات المدعمة للتيجان الخلفية باستخدام دعامات بزوايا ميل مختلفه | Authors | Samar Saeed Taha Bedair | Issue Date | 2016 |
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