Crestal Bone Resorption Clinical Trial
Official title:
Clinical Evaluation Of Dental Implants Stability Placed In Healed Bony Sites Following Over-drilling Compared To Conventional-Drilling Protocol: A Randomized Controlled Trial.
Clinical Evaluation Of Dental Implants Stability Placed In Healed Bony Sites Following Over-drilling Compared To Conventional-Drilling Protocol
- Statement of the problem:
peri-implant bone is affected by excessive mechanical stress, the mechanism of bone formation
is reduced and the bone resorption is increased, leading to MBL. Isidor F. 2006, Warreth A,
009 A drilling sequence using a drill that is smaller than the implant diameter has been
applied as a way to obtain enough initial stability.Bilhan H,2010 However, the implant can be
extremely compressed or exceed the torque, which can be higher than the elastic limit of bone
when a drill that is smaller than the implant diameter is used. This may affect the bone
surrounding the implant and may also lead to a micro fracture.
Frost mentioned that alveolar bone density is changed by micro deformation due to
modification of the physical condition. Bone resorption and fibrous tissue production
progress if the micro deformation rate is higher than 3,000 micro strain (με). Also,
continuous bone replacement occurs while woven bone appears. Wolff J.1986 Bone tissue adapts
to the change of stress while minimizing its weight and transforming its structure. Frost
HM,1989 The bone formation mechanism is inhibited and the bone resorption mechanism is
enhanced if excessive mechanical stress is applied to alveolar bone during implantation,
resulting in the progression of marginal bone loss (MBL). Isidor F.2006 , Warreth A,2009-
Rationale for carrying out the trial:
Success and survival rate of an implant are directly associated with primary stability.
Friberg B,et al 1991 Primary stability is achieved with initial rigid fixation of implants
during the surgery and considered necessary for a successful osseointegration. Sennerby L,et
al 1992, Rodrigo D,et al 2010 There are two different processes of bone formation at implant
sites; contact and distance osteogenesis. Contact osteogenesis infers new bone formation in
direct contact with the implant surface. Distance osteogenesis is the new bone formation on
the surfaces of the parent bone and occurs when primary stability is absent at implant site.
Davies JE.et al 2003, Sivolella S,et al2012
When there is a gap between the implant surface and bone, a clot will fill the space and will
be replaced by a provisional connective matrix that will act as scaffold for formation of
woven bone. Berglundh T,et al,2003 , Rossi F,2012 Our study will evaluate the effect of
oversized drilling on implant success and secondary stability
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