Osseo integrated implant being the most sought after modality of treatment, optimal occlusion plays a key role in implant supported prosthesis. The probable reason for peri-implant disease or crestal bone loss & failure of implant prosthesis is occlusal overloading of implants.
This is a review to discuss the clinical guidelines for various occlusal schemes like balanced, group function, mutually protected occlusion. Appropriate occlusion is the foremost mandatory for long term survival of implants in absence of sound clinical situations. This is because poor occlusion increases the magnitude of mechanical stress & strains at the crestal bone.
Misch proposed implant-protective occlusion which states that by decreasing the occlusal forces increases the clinical success of implants & its prosthesis.
Keeping aside the conventional occlusal concepts, refinements proposed to reduce stress at the implant interface are
Ø Mutually protected articulation
Ø Implant body angle to occlusal load
Ø Crown height
Ø Quality of implant crowns
Ø Timings of Occlusal contacts
The biggest question of the hour is why occlusion is the most important factor? Since the periodontal ligament – mediated proprioception doesn’t occur with implants as in natural teeth; occlusal forces are to be carefully accomplished in order to regulate mandibular displacement.
Each of the prosthesis i.e implant supported prosthesis, tooth or tissue supported prosthesis exerts different range of forces in both the functional & resting movements. The implant supported prosthesis is designed as that of tooth supported single fixed partial prosthesis with an adequate interarch space with bilateral stability in centric occlusion & no interferences between retruded & centric position. In terms of posterior fixed implant prosthesis reduced inclination of cusps, narrow occlusal table, and increased proximal contacts provides stability to the restorations.
The current accepted paradigm shift is mid retrognathia-flat lingual incisal platform in skeletal class II div II, raise vertical dimension at occlusion to flatten anterior guidance in skeletal class II Div II, to slightly disocclude posterior or mild anterior disocclusion in skeletal class III.
In cases of natural dentition little degree of flexibility is acceptable but in implants the flexibility degree is supposed to be decreased to zero for the success of prosthetic rehabilitation.
Dr. Prof. Rajat Sachdeva
Director & Mentor
Dr.Sachdeva’s Dental Institute
I-101 Ashok Vihar Phase 1 Delhi 110052