carl misch; dental implant prosthetics; 2ed; 2014. ch. 24

Carl Misch; Dental implant prosthetics; 2ed; 2014. Ch. 24

4 or 6 implants betw. mental foraminae & distal cantilever off each side to replace posterior teeth (5)

The anterior arch form (square, oval, tapered) is related to the anterior most implant position

The foraminae position affects the position of distal most implants

A-P distance of greater than 8 mm A-P distance of 6 to 8 mm

A-P distance of 2 to 5 mm

Mental foramenae may be located as far anterior as just distal to the canine (more common in white women) and as far distal as the mesial of the first molar apex (more often in black men).

Cutright B, Quillopa N, Shupert W, et al. An anthropometric analysis of key foramina for maxillofacial surgery. J Oral Maxillofac Surg. 2003;61:354–357.

For five anterior implants in anterior mandible, cantilever should not exceed 2 times A-P spread, with all other stress factors being lowA cantilever rarely indicated on 3 implants, even with simillar A-P spread as 5 implants

Narrow implants are not designed to support cantilevers

Reserve this option for patients with low force

factors (older female, wearing upper denture,

abundant anterior bone, CHS to 15 mm, tapered or

ovoid mandibular arches, & posterior segments of

inadequate height for endosteal implant)

A slight variation of Branemark protocol to place additional implants above mental foraminae

A prerequisite available bone in height and width over foraminae

A minimum recommended implant height of 9 mm & a greater diameter of an enhanced surface area recommended

No. of implants may be increased to as many as 7 A-P spread for implant placement is greatly increased

Length of cantilever is

reduced

Key implant positions: second premolars, canines, centeral incisor or midline position

One posterior segment connected to anterior segment

key implant positions first molar (on one side), bilateral 1st premolars, bilateral caninesSecondary positions second premolar on same side as molar implant, central incisor (midline)

Option 3 is better than 1 & 2:

A-P spread 1.5 to 2 times greater

When force factors are greater, 6 or 7 implant may be used (5 implant between foraminae & one or two implant distal on one side)

One piece casting can be fabricated & one cantilever to opposite side of molar implant would replace those posterior teeth

Treatment option 3Treatment option 3

Requires available bone in at least one posterior region

Bilateral posterior implants that they are not splinted together

Key implant positions: First molars, first premolars, canines

Secondary implant positions

second premolars and/or

incisor


advantages:

1.Elimination of cantilever2.Risk of uncemented restorations & occlusal overload reduced3.Prostheses has two segments rather than one

Disadvantages 1. Need for abundant bone in both posterior region 2. Additional cost

Treatment option 4 Treatment option 4 is selected :1.When force factors are great or bone density is poor2.When the body of mandible is division C-h & subperiosteal or disc like implants are used for posterior

Three independent prostheses


Advantages:

• Smaller segments for individual restorations

• Most flexibility and torsion of mandible


Disadvantages:• Greater number of implants required•Available bone needs are greatest

•Most common scenario for option 5 is when posterior mandible is C-H bone volume & a circumferential subperiosteal or disc-design implant is used as second premolar & first molar

From 7 to 10, with at least 3 implants from canine to canine

Carl Misch; Dental implant prosthetics; 2ed; 2014. Ch. 25 26

In the case of heavy stress factors, an additional anterior implant and bilateral second molar positions (to increase the anteroposterior distance) may be of benefit

The dentist may use the following guidelines for implant locations in a completely edentulous maxilla:

1. The bilateral canine position is a key implant position and is planned for 4-mm-diameter implants.

2. The center of the first premolar is planned 7 to 8 mm distal from the center of the canine implant (for a 4.0-mm-diameter implant). This is an optional implant site when parafunction is moderate to severe.

3. The center of the second premolar is 7 to 8 mm distal from the first premolar site (14 mm from the midcanine position) on each side for a 4.0-mm-diameter implant. This is a key implant position.

4. The distal half of the first molar is 8 to 10 mm distal from the mid second premolar implant (this places the implant in the distal of the first molar and increases the A-P distance). Ideally, the implant should be 5 to 6 mm in diameter. This is a key implant position. When a 4-mm diameter is used, the first implant is 7 to 8 mm from the mid second premolar site, and the second implant is 7 to 8 mm more distal than the first implant.

5. The center of the second molar is 8 to 10 mm distal from the center of the first molar implant. This position is most important for the edentulous arch with a tapered dentate arch form, D4 bone types, or severe force factors.


Square, ovoid, and tapering


Arch FormAnterior Cantilever (mm)

Number of Implants

Implant Position

Square <8 2 Canines

Ovoid 8-12 3Two canines and one incisor

Tapering >12 4Two canines and two incisors


Treatment with mandibular IFCDPs yields high implant and prosthodontic survival rates (more than 96% after 10 years).

Rough surface implants exhibited cumulative survival rates similar to the smooth surface ones in the edentulous mandible.

Papaspyridakos et al. Implant and Prosthodontic Survival Rates with Implant Fixed Complete Dental Prostheses in the Edentulous Mandible after at Least 5 Years: A Systematic Review Clinical Implant Dentistry and Related Research, Volume 16, Number 5, 2014

The number of supporting implants and the anteroposterior implant distribution had no influence on the implant survival rate. The prosthetic design, the veneering material, and the retention type had no influence on the prosthodontic survival rates. The loading protocol also had no influence on the prosthodontic survival rates.

Papaspyridakos et al. Implant and Prosthodontic Survival Rates with Implant Fixed Complete Dental Prostheses in the Edentulous Mandible after at Least 5 Years: A Systematic Review Clinical Implant Dentistry and Related Research, Volume 16, Number 5, 2014

A recent meta-analysis showed that technical complications are frequently encountered with IFCDPs during 5 to 10 years of clinical function. The 10-year cumulative rate of “prosthesis free of complications” of 8.6% reported in that review opitomizes the advantage of retrievability of screw-retained IFCDPs vs cement-retained metal-ceramic IFCDPs.

Papaspyridakos P, Chen CJ, Chuang SK, Weber HP, Gallucci GO. A systematic review of biologic and technical complications with fixed implant rehabilitations for edentulous patients. Int J Oral Maxillofac Implants 2012; 27: 102–110.

The insertion of four implants for a fixed restoration in the edentulous mandible reveals satisfying results. However, it has to be noticed that five or more implants showed a slightly better outcome.

Kern et al. A systematic review and meta-analysis of removable and fixed implant supported prostheses in edentulous jaws: post-loading implant loss. Clin. Oral Impl. Res. 00, 2015, 1–22

Implants with rough surfaces showed a statistically higher survival rate than machined implants at all intervals. Implants placed in augmented bone had a statistically lower survival rate, except for rough-surface implants, for which no statistical difference between augmented and non-augmented bone survival rates was found. Machined implants showed a stable survival rate only when placed in native bone. When machined implants were placed in augmented bone, the survival rate decreased significantly at each study endpoint.

Lambert FE,Weber HP, Susarla SM, Belser UC, Gallucci GO. Descriptive analysis of implant and prosthodontic survival rates with fixed implant-supported rehabilitations in the edentulous maxilla. J Periodontol 2009; 80:1220–1230.

The prosthetic design, veneering material, and the number of prostheses per arch had no influence on the prosthodontic survival rate.

Implant number and distribution along the edentulous maxilla seemed to influence the prosthodontic survival rate.

Lambert FE,Weber HP, Susarla SM, Belser UC, Gallucci GO. Descriptive analysis of implant and prosthodontic survival rates with fixed implant-supported rehabilitations in the edentulous maxilla. J Periodontol 2009; 80:1220–1230.

The insertion of six or more implants for a fixed reconstruction in the maxilla reveals favorable results.

Considering the “all-on-4” concept for the maxilla, one study (Crespi et al. 2012) with an acceptable level of evidence was found, revealing a satisfactory outcome.


Implants with fixed prostheses show slightly but significantly better results than removable prostheses regarding both jaws.Rough-surfaced implants demonstrated favorable results compared to machined implants.


carl misch; dental implant prosthetics; 2ed; 2014. ch. 24

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