TOPIC: Introduction, Diagnosis and Treatment Planning
🎯 KEY POINTS:
🔹Dahl of Germany introduced the mucosal inserts or button implants for maxilla in 1940.
🔹Dahl also conceived the concept of the subperiosteal implants.
🔹Goldberg and Gershkoff made subperiosteal implant with vitallium in 1948.
🔹Sollier, Chercheve and Small introduced the transosteal implant in 1953.
🔹L.I. Linkow in 1966 introduced the endosseous blade vent implant.
🔹First extraoral implant was placed for the auricular prosthesis by P.I. Branemark in 1977.
🔹Implants can be placed minimum 6 months after the radiotherapy.
🔹Radiation dose of OPG is less than the full mouth periapical radiographs.
🔹Lateral skull radiograph is used to study ridge profile of both upper and lower jaws in the midline.
🔹In CT scans, the metal markers should be avoided as these produce scattering of the image.
🔹Scan Ora is a new generation sophisticated tomograph which is used to generate high-quality sectional image.
🔹Narrow diameter implants less than 3.5 mm should be avoided in the posterior region or number of implants should be increased.
🔹Narrow diameter implants greatly reduce the strength and the surface area for osseointegration or load distribution.
🔹D4 type of bone represents the worst type of bone used for implant placement.
🔹The factors such as the quality of bone, type and design of implant to be used, the anatomical anomaly and technique of use determine the efficacy of the osteotome used in the posterior maxilla.
🔹The effective radiation dose with CBCT is significantly lower than that of conventional CT.
🔹The CT imaging 3G software can produce high-quality images on the paper, films or in the digital form.
🔹Surgical template is a useful diagnostic tool to guide the implant in desired angulation during placement.
🔹Implant-supported prosthesis has the poorest prognosis of the patient with parafunctional habits such as bruxer.
🔹Microstrain can be a favourable stimulus during healing period of implants resulting in increased bone density.
🔹Branemark design is called the bone-anchored bridge which consisted of cast metal bar attached to the acrylic teeth and gumwork attached to the number of implants. This resembles denture on stilts.
🔹The ‘All and 4 Shelf’ concept was first described by Dr Paula Malo in 1998.
DENTAL IMPLANT
🔎 DEFINITION:
A prosthetic device made of alloplastic materials implanted into the oral tissues beneath the mucosal or/and periosteal layer, and on/or within the bone to provide retention and support for a fixed or removable dental prostheses. (GPT 8th Ed)
📢 PARTS OF DENTAL IMPLANT
👉 Components of dental implants:
- Implant body
- Cover screw
- Healing cap or gingival former
- Abutment
- Impression post
- Laboratory analogue
- Waxing sleeve
🔍 CLASSIFICATION OF DENTAL IMPLANT
✳️ On the Basis of Placement of Implants Within the Tissues
👉 There are three primary types of implants based on their placement within the tissues:
- Subperiosteal Implants: These implants rest on the bone surface without penetrating it.
- Transosteal Implants: These implants pass through both cortical plates of the jawbone.
- Endosteal Implants: These implants are placed within the bone itself, either as root-form or plate-form implants.
✳️ On the Basis of Type of Material Used
(a) Metallic implants: Titanium and its alloys, cobalt–chromium, molybdenum alloy, iron–chromium–nickel-based alloys are some examples of metallic implants.
(b) Nonmetallic implants: Ceramics and carbon are some examples of nonmetallic implants.
✳️ On the Basis of Treatment Options of Completely Edentulous Arches (Misch)
👉 The Misch classification divides the completely edentulous jaw into three segments: anterior, left posterior, and right posterior. It categorizes these segments based on bone quality and quantity, determining suitable implant treatment options:
🔶 Type 1:
- Div A: Abundant bone in all segments.
- Div B: Adequate bone for narrow implants.
- Div C-w: Inadequate bone width, requiring augmentation.
- Div C-h: High crown-to-implant ratio, favoring removable prostheses.
- Div D: Severe atrophy, requiring augmentation or conventional dentures.
🔶 Type 2:
- Div A, B: Abundant anterior, adequate posterior bone.
- Div A, C or D: Similar to Type 1.
- Div B, C: Requires osteoplasty and augmentation.
- Div B, D: Advanced posterior atrophy, suitable for maxilla only.
🔶 Type 3:
- Div A, B, D: Abundant anterior, moderate posterior right, severe posterior left bone. Sinus lift or cantilever design may be used.
- Div C, D, C: Severe right, moderate left atrophy. Cantilever or subantral augmentation/subnasal elevation may be used.
✳️On the Basis of Treatment Options of Partially Edentulous Arches
👉 Misch’s classification categorizes partially edentulous arches based on bone quality and quantity in the edentulous areas:
🔶 Class I: Bilateral posterior edentulism
- Div A: Abundant bone, suitable for root-form implants and independent prostheses.
- Div B: Moderate bone width, requires osteoplasty or narrow diameter implants.
- Div C: Inadequate bone, needs augmentation.
- Div D: Severe resorption, major augmentation required.
🔶 Class II: Unilateral posterior edentulism
- Similar to Class I divisions.
🔶 Class III: Unilateral edentulism with teeth on both sides
- Similar to Class I divisions.
🔶 Class IV: Anterior edentulism crossing the midline
- Similar to Class I divisions.
✳️ On the Basis of Treatment Options
👉 Misch (1989) proposed five treatment options for implant-supported prostheses:
🔶 Fixed Prostheses:
- FP1: Replaces only the crown, resembling a natural tooth.
- FP2: Replaces the crown and a portion of the root, with altered gingival contour.
- FP3: Replaces crowns, gingival tissues, and part of the edentulous site, often using denture teeth and acrylic gingiva.
🔶 Removable Prostheses:
4. RP4: Overdenture supported entirely by implants.
5. RP5: Overdenture supported by both soft tissues and implants.
✳️ On the Basis of their Reaction to Bone
🔶 Bioactive: These materials stimulate bone growth and formation. Hydroxyapatite is a common example.
🔶 Bioinert: These materials do not directly bond to bone but are mechanically retained in place.