51. Implant surgery.

Question 1

Basic principles for implant site preparation to ensure successful osseointegration

Answer 1

• Implants sterile and of biocompatible material=>titanium
• Sterile conditions
• Atraumatic technique=>avoid overheating bone
• Placing implants w/ good initial stability
• Allowing healing without loading or micromovement for 2-4 or 4-6 months=>
• Depending on bone density, bone maturation, implant stability

Question 2

Key steps in flap elevation for implant placement

Answer 2

• Incisions w/ crestal or vestibular approach
• Crestal incisions where ridge wide and in one-stage implantation
• Buccal approach if crest is high but narrow or in ridge augmentation procedures=>
• Avoid early exposure of bone substitute or membrane
• Gingiva (papillae) of neighboring teeth not included in flap=>
• Avoid shrinkage and black triangles in esthetic zone
• Including gingiva in flap for narrow edentulous sites close to teeth=>
• Combined w/ vertical releasing incisions for adequate flap dimension and vascular support
• Releasing entire periosteum properly from jaw walls to include it in full-thickness flap
• Facilitating irrigation (cooling) during drilling by elevating and exposing osseous tissue

Question 3

Advantages of flapless implant insertion

Answer 3

• Reduction in complications
• Reduced surgical time
• A good fit between implant and soft tissues=> facilitatin restorative phase of treatment

Question 4

Model-based guided surgery technique for implant placement

Answer 4

• Plaster model=>represents edentulous area=>
• Planning and performing implant insertion on the plaster model=>
• Most convenient position for permanent restoration
• Preparation of surgical template w/ sleeves (canals) to guide drilling
• Replicating soft tissues of recipient site=>
• Allowing fabrication of provisional restoration before implantation

Question 5

Precautions taken to avoid neurosensory disorders during implant insertion

Answer 5

• Avoid mechanical compression or direct injury to nerves=>
• Neural degenerative processes, edema, or local hematoma
• X-ray analysis of lower jaw when planning implant placement near the mental foramen or inferior alveolar nerve=>
• Prevent anesthesia, paresthesia, or dysesthesia

Question 6

Potential risks associated with implant placement in the anterior and posterior mandible

Answer 6

• Severe hemorrhage in floor of mouth=>
• Airway obstruction=>close proximity of sublingual and submental arteries to the lingual cortical plate
• Displacement of tongue and floor of mouth superiorly and posteriorly=>
• Hematoma=>obstructing upper airway and requiring tracheostomy or intubation

Question 7

How implant position determined during surgery

Answer 7

• Starting w/ most distal implants in fully edentulous jaws
• Minimum bone presence of 4(5) mm horizontally and about 7(9) mm vertically in recipient site

Question 8

Recommended number of implants for partially edentulous patients

Answer 8

• Three implants=>avoid overloading anchorage unit
• Placed in tripod position instead of straight line =>minimize transmission of bending forces onto each individual implant

Question 9

Considerations made for implant direction and inclination

Answer 9

• Implants in tooth position, w/ long axis directed through occlusal surface of the final restoration
• Long axis of mandibular implants directed towards limbus part of incisors or palatal cusps of maxillary teeth
• Inclination based on existing jaw relations=>
• Vertically in class I
• Vertically in the maxilla and slightly buccally in mandible for class II
• Buccally in maxilla and more lingually in mandible for class III

-Considering orthognathic surgery or an overdenture retained by a bar construction on 2-4 implants for markedly adverse jaw relations

Question 10

Recommended healing time for implants

Answer 10

• 3-4 months following installation of implants w/ turned surface
• 5-6 months for maxilla and occasionally posterior areas of mandible=>more cancellous bone
• Reduced healing times of 6 weeks=>implants w/ modified surface recommended for early or immediate loading protocols

-Additional 1-2 months for implants placed in quality 4 bone of the mandible.

Question 11

How initial implant stability measured

Answer 11

• Resonance frequency analysis=>
• Allows repeated analysis of bone quality over time without invasive techniques
• An Implant Stability Quotient (ISQ) value>60 recommended to allow oral implants to be loaded directly after insertion=>
• Good initial stability and higher likelihood of successful osseointegration