Proper case selection is needed for a successful implant therapy. For a successful implant case, an appropriate healing response is required. Not all edentulous patients are candidates for implant therapy. Absolute medical contraindications exist and must be adhered to. In order to avoid any infection, implant failure, or even patient death. But then there are conditions, if stabilized, they do not interfere with healing; those are relative contraindications to elective oral surgery. The careful practitioner understands the nature of a number of diseases assess evidence regarding implant therapy in such patients and picks his or her cases based on this knowledge. It is an informed choice that we make, and if we choose properly, predictability results.

Aim – The purpose of this study was to evaluate and compare the effect of two cordless retraction techniques and their influence on gingiva.


Material and Methods – Participants (n=40) with healthy gingival conditions were recruited- an expanding polyvinyl material(Magic foam cord), a paste like material (Expasyl) were applied in the posterior tooth of the subjects. Following impressions casts was measured for the gingival retraction with 3D scanner. Gingival health was assessed after one week and the collected data was tabulated and subjected to statstical analysis.


Result- Mean gingival displacement obtained by the Expasyl paste was more effective as compared to the magic foam cord i.e, 0.30mm and 0.23mm respectively and the obtained “p� value was p<0.001 which was extremely significant.


Conclusions – Within the limitations of this study the conclusions were made that both the retraction agents were convenient to use, painless and they achieved the adequate gingival retraction and they wont result in any gingival inflammation and gingival recession.

Aim

This study's objective was to assess and analyze, using 3D Finite Element Analysis, the impact of four mandibular complete arch superstructures on the distribution of stress in the crestal bone during mandibular flexure.

Materials and methods

Four Finite element models of the mandible with different implant-retained framework designs have been developed. Three of these models had six axial implants placed at intervals of 11.8 mm, 18.8 mm and 25.8 mm from the midline, respectively. One model had two tilted implants and four axial implants splinted with a single piece of framework at intervals of 8.4 mm, 13.4 mm and 18.4 mm from the midline. For analyzing the stress distribution, the finished product was transferred to ANSYS R 18.1 software (Sirsa, Haryana, India) for finite element simulation, the models were constructed, the ends were restrained, and bilateral vertical loads of 50N, 100N and 150N were applied to the distal part of the framework.

Results

Bilateral loads were applied to each of the four 3D FEM and after assessment of Von Mises Stress and Total Deformation, a finding was made that the model with six axial implants supported by a single piece of framework underwent the highest total deformation and the model with four axial implants and two implants with distal tilts displayed most significant Von Mises stress.

Conclusion

Within the constraints of this 3D FEA, it was determined that mandibular flexure and peri-implant bone stress were affected by the way the framework is divided and the nature of mandibular movement. The three types of frames with the least bone stress are demonstrated by the mandibular deformation that results from two-piece frameworks on axial implants. Regardless of the number of implants, the single framework splinted with six implants shows a flexure in mandible with the highest bone stress around the implant irrespective of the angulation of the implant.

Clinical significance

When it comes to edentulous jaws, reducing stress in implant-supported restorative systems at varying degrees of the bone and implant interfaces and superstructures of prosthetics is one of the fundamental goals of implant treatment. A framework with proper design and a low modulus of elasticity reduces mechanical risk. Additionally, a larger number of implants helps to prevent cantilevers and spacing between the implants.