1. Single-Tooth Replacement: Treatment Options
Presented by:Dr.m.akouchakian
Supervised by: Dr. Mansour Rismanchian
And Dr.saied Nosouhian
Dental of implantology
Dental implants research center
Isfahan university of mediacal science

2. Single-Tooth Replacement: Treatment Options
chapter 16
m.akouchekian

3. Seventy percent of the dentate population in the United States is missing at least one tooth
Single-tooth replacement will most likely comprise a larger percentage of prosthetic dentistry in the future, compared with past generations.
m.akouchekian

4. POSTERIOR MISSING TOOTH
The first molars are the first permanent teeth to erupt in the mouth
often the first to decay
often play a pivotal role in the maintenance of the arch form and proper occlusal schemes
m.akouchekian

5. The primary cause of failure of the crown: endodontic therapy
the adult patient often has had one or more crowns fabricated to restore the integrity of the tooth and replace previous large restorations.
Longevity reports of crowns have yielded very disparate results, with the mean life span at failure reported to be 10.3 years.
The primary cause of failure of the crown:
endodontic therapy
porcelain or tooth fracture (or both)
uncemented restoration
m.akouchekian

6. POSTERIOR SINGLE-TOOTH REPLACEMENT OPTIONS
m.akouchekian

7. correction of the occlusal plane and maxillomandibular relationships
Regardless of the treatment selected, the interocclusal space must be assessed carefully.
insufficient vertical space
correction of the occlusal plane and maxillomandibular relationships
prosthes
m.akouchekian

8. Removable Prosthesis A common axiom in restorative dentistry :
use a fixed prosthesis whenever possible
RPDs are usually indicated to replace:
three or more posterior teeth
a missing canine and two or more adjacent teeth
m.akouchekian

9. Removable Prosthesis
no reported advantages exist for an RPD replacing one posterior tooth.
m.akouchekian

10. Removable Prosthesis the two primary reasons for the patient
to consent to wearing the restoration
the fear of other teeth shifting in the arch
esthetics
m.akouchekian

11. Resin-Bonded Fixed Partial Denture
m.akouchekian

12. Resin-Bonded Fixed Partial Denture
m.akouchekian

13. Resin-Bonded Fixed Partial Denture
earlier perforated designs exhibited lower survival rates
The majority of resin-bonded fixed partial denture (FPO) failure occurs from cement failure
survival rates :
Max. Ant > mand. Ant > max. Post > mand. post
m.akouchekian

14. Resin-Bonded Fixed Partial Denture
Selection:
economics
maintain tooth structure on the abutment teeth
transitional restoration
m.akouchekian

15. Maintenance of the Posterior Space
Replace a missing tooth to prevent :
tipping,extrusion, increased plaque retention,caries, periodontal disease, and collapse of the integrity of the arch
m.akouchekian

16. m.akouchekian

17. mandibular second molar is often not replaced
when the third molar and second molar are the only posterior mandibular teeth missing
mandibular second molar is often not replaced
m.akouchekian

18. when the third molar is present
The mandibular second molar is usually replaced
m.akouchekian

19. Disadvantage of not replace a mandibular second molar
extrusion and loss of the maxillary second molar
loss of proper interproximal contact with the adjacent tooth
increased risk of caries, periodontal disease,or both
To preven extrusion of the maxillary second molare
a crown on the mandibular first molar include an occlusal contact
with the mesial marginal ridge of the maxillary second molar
the maxillary second molar bonded to the maxillary first molar
m.akouchekian

20. Fixed Partial Denture
m.akouchekian

21. Fixed Partial Denture
m.akouchekian

22. m.akouchekian

23. Single-Tooth Implants
From 1993 to the present time, single-tooth implants have become the most predictable method of tooth replacement.
A review of the literature by Goodacre
from 1981 to 2003:
single-tooth replacement with an implant had the highest implant prosthesis survival rate(97%).
m.akouchekian

24. m.akouchekian

25. Single-Tooth Implants
the longevity of the implant crown has not been adequately determined
However, lO-year data clearly indicate an implant and its associated crown has greater survival than an FPD
most common complication reported :
abutment screw loosening(did not cause the prosthesis or implant to fail)
m.akouchekian

26. the implant failure almost always results in bone loss
The consequences of early failure may be greater for a single-tooth implant compared with a three unit fixed prosthesis.
the implant failure almost always results in bone loss
implant failure:
does not compromise the adjacent teeth
does not increase the risk of their loss
m.akouchekian

27. m.akouchekian

28. Transitional Restorations
Use in esthetic regions during implant healing
A removable transitional restoration:
load the soft tissue over a bone graft
compromise the result and volume of the augmentation
cause bone loss, or perhaps even implant failure from the early loading around the implant during Stage I healing
depress the interdental papillae of the adjacent teeth
m.akouchekian

29. a resin-bonded fixed restoration:
replacing teeth in the esthetic zone
provide an improved function
protect the region
In the esthetic zone when bone grafting is necessary
Use transitional restoration
m.akouchekian

30. Dont use of transitional posterior tooth
during bone augmentation and implant healing in a nonesthetic region (mandibular post)
Dont use of transitional posterior tooth
overall cost of treatment
Short clinical crowns
unfavorable occlusal relationships
m.akouchekian

31. IMPLANT BODY SELECTION
The most common problem associated with a single tooth is abutment screw loosening
an antirotational feature (i.e.,external or internal hex)
Accuracy of component fit
abutment screw design
the number of threads
m.akouchekian

32. should be made of titanium alloy to reduce the risk of long-term fracture
4 times more resistant to fracture than grade 1 titanium
2 times as strong as grade 3 titanium
functional surface :
threaded implant > cylinderical imlplant
parallel walled implant > tapered implant
m.akouchekian

33. 1.5 to 2.0 mm from an adjacent tooth
The ideal diameter of a single-tooth implant is dependent on:
the mesiodistal dimension of the missing tooth
the buccolingual dimension of the implant site
1.5 to 2.0 mm from an adjacent tooth
1.5 mm from the lateral width of the ridge
intratooth posterior region:
at least 3 mm less than the mesiodistal dimension of the missing tooth (from CEJ to CEJ)
3 mm narrower than the buccolingual dimension of bone
m.akouchekian

34. PREMOLAR IMPLANT REPLACEMENT
The most ideal posterior tooth to replace with an implant
The vertical available bone is usually greater
almost always:
anterior or below the maxillary sinus (or both)
anterior to the mental foramen
The bone trajectory for implant insertion is more favorable
m.akouchekian

35. often in the esthetic zone need for bone grafting is very common
maxillary premolars:
often in the esthetic zone
need for bone grafting is very common
Implant placement without bone grafting
recessed emergence profile
facial ridge lap to the crown
does not allow proper hygiene or probing
m.akouchekian

36. improves the cervical emergence profile of the maxillary
To ensure a proper esthetic result and to avoid the need for a crown with a ridge lap
the implant body is often positioned similar to an anterior implant, under the buccal cusp
improves the cervical emergence profile of the maxillary
premolar crown
m.akouchekian

37. at a distance of 2 mm below the CEJ The natural premolar:
root diameter is 4.2 mm consequence
most common implant diameter is about 4mm at the crest module.
when the mesiodistal space is 7 mm or greater:
1.5 mm of bone on the proximal surfaces adjacent to the natural teeth
when the mesiodistal dimension is only 6.5 mm:
3.5-mm implant is suggested
m.akouchekian

38. placed parallel to the canine root, and a shorter
The maxillary canine root is often angled 11 degrees distally and presents a distal curve 32% of the time
placed parallel to the canine root, and a shorter
second premolar apices may be located over the mandibular neurovascular canal or maxillary sinus:
reduced height of bone
a shorter implant
m.akouchekian

39. FIRST-MOLAR IMPLANT REPLACEMENT
Its mesiodistal dimensionusually ranges from 8 to 12 mm
The magnified occlusal
forces (especially important in parafunction) may cause:
bone loss
complicate home care
Increase abutment screw loosening
increase abutment
or implant failure because of overload.
m.akouchekian

40. FIRST-MOLAR IMPLANT Rangert et al:
overload-induced bone resorption appeared to precede implant fracture in a significant number of single-molar implant restorations.
When possible, a larger-diameter implant should be inserted to enhance the mechanical properties of the implant System:
increased surface area
stronger resistance to component fracture
increased abutment stability
enhanced emergence profile for the crown
m.akouchekian

41. FIRST-MOLAR IMPLANT larger-diameter implant:
use of wide-diameter implants:
in bone of poor quality
for the immediate replacement of failed implant
larger-diameter implant:
does not require as long an implant
Is a benefit in post
(anatomical limitations and landmarks, such as the maxillary sinus or mandibular canaI)
m.akouchekian

42. FIRST-MOLAR IMPLANT When the mesiodistal dimension is 14 mm or greater
two 4-mm-diameter implants should be considered
Eliminate the mesiodistal offset loads to the prosthesis
greater total surface area
More stress reduction
reduces the incidence of
abutment screw loosening
m.akouchekian

43. FIRST-MOLAR IMPLANT whenever possible,
two implants should be used to replace a larger singlemolar space to reduce cantilever loads and abutment screw loosening
m.akouchekian

44. FIRST-MOLAR IMPLANT subtracting 6 mm: and dividing by 2
1.5 mm from each tooth for soft tissue and surgical risk
3 mm between the implants
and dividing by 2
m.akouchekian

45. FIRST-MOLAR IMPLANT When the mesiodistal space is 12 to 14 mm:
the treatment plan of choice is less obvious
A 5-mm-diameter implant may result in cantilevers up to 5 mm on each marginal ridge of the crown
two implants present a greater surgical, prosthetic, and hygiene risk
The primary goal is to obtain at least 14 mm of space
m.akouchekian

46. FIRST-MOLAR IMPLANT Additional space may be gained in several ways:
Enamoplasty of the adjacent teeth's proximal contours
Orthodontics to
upright a tilted
Second molar
m.akouchekian

47. FIRST-MOLAR IMPLANT increases the mesiodistal space by 0.5 to 1.0 mm
one implant is placed buccal and the other on a diagonal toward the lingual
increases the mesiodistal space by
0.5 to 1.0 mm
m.akouchekian

48. FIRST-MOLAR IMPLANT In the mandible:
Ant. implant is placed to the lingual
distal implant is placed to the facial
access of a floss threader from the
vestibule into the intrairmplant space
occlusal contacts on
the central fossa of buccal
aspect of the mesial implant
m.akouchekian

49. FIRST-MOLAR IMPLANT In the maxilla:
anterior implant is placed to the buccal
distal implant to the palatal region,
to improve the esthetics
distal occlusal contact is
Placed over the lingual cusp
mesial occlusal contact is
located in the central fossa
access of a floss threader
from the palatal
m.akouchekian

50. FIRST-MOLAR IMPLANT
m.akouchekian

51. MAXILLARY ANTERIOR TOOTH REPLACEMENT
m.akouchekian

52. ESTHETIC MAXILLARY ANTERIOR TOOTH REPLACEMENT
is often the most difficult procedure to perform in all of implant dentistry
highly esthetic zone
requires both hard (bone and teeth) and soft tissue restoration
The soft tissue drape is often the most difficult aspect of treatment
m.akouchekian

53. MAXILLARY ANTERIOR TOOTH REPLACEMENT
m.akouchekian

54. Fixed Partial Denture can be fabricated in shorter time
is more predictable in the short term
often satisfies the criteria of normal contour, comfort,function, esthetics, speech, and health
However, 7-to 9-year survival estimates for a three-unit FPO are often less than 75%
m.akouchekian

55. Fixed Partial Denture
The most common complications associated with FPD failure:
caries
endodontic complications(including fractures)
uncemented restorations(leading to decay)
risk of endodontic treatment :
15% for an FPD abutment
3% to 5% risk for a single crown
additional tooth preparation for parallelism of the abutments
the repreparation of teeth after prosthesis failure
the increased risk of decay on the abutment teeth
m.akouchekian

56. Advantages of a Fixed Partial Denture
Patient Compliance and Patient Fear
an implant restoration:
many steps of treatment
Orthodontics,Soft tissue surgeries, bone graft
surgery, implant surgery, and several prosthetic steps
m.akouchekian

57. a traditional three-unit fixed prosthesis:less than 3 weeks
Time of Treatment
The time required for an implant to heal and be restored :3 to 6 months
If bone grafting and soft tissue rehabilation are required: more than 1 year
a traditional three-unit fixed prosthesis:less than 3 weeks
m.akouchekian

58. Consequence of Failure
The consequences of short-term failure of bone graft, implant, or prosthetic are greater for a single-tooth implant, compared with a three- unit fixed prosthesis
The implant failure may result in:
bone loss (especially when it occurs in the anterior regions)
may include the support system of the adjacent teeth
soft tissue recession
devastating effects on the esthetics
bone grafting may be required
Additional soft tissue reconstruction
These additional procedures are most often at the expense of the doctor
m.akouchekian

59. The most common contraindication for a traditional fixed prosthesis and indication for a single-tooth implant in the anterior regions of the mouth is the patient's desire
m.akouchekian

60. The laboratory fee to the doctor for three crowns:low.
Cost to Patient
The laboratory fee to the doctor for three crowns:low.
The implant body, abutment,analog, and final crown fee:more expensive
Although the initial cost of treatment for an implant single crown: higher
implant reconstruction was a better financial option in the long term
m.akouchekian

61. Adjacent Tooth Mobility
the adjacent teeth of the anterior implant site should exhibit minimum mobility
if all other periodontal indices are normal, Natural tooth longevity is not related to mobility
a traditional FPD decrease the abutment mobility
m.akouchekian

62. Unfavorable Tooth Size and Position
the maxillary anterior central incisors may be misplaced, angled, rotated, or smaller than ideal =>
An FPD replacing a lateral incisor:
improve the position and size of the central incisor
The canine may be made slightly narrower to make the lateral incisor similar in size to the contralateral incisor
several cosmetic advantages especially when the lateral edentulous sites are smaller than 5 mm in width
m.akouchekian

63. Cantraindicatians for a Fixed Partial Denture
m.akouchekian

64. Cantilevered Fixed Partial Denture
worse prognosis than a traditional FPD
The genesis of failure is usually an uncemented restoration
when the canti lever is short,limited occlusion on the pontic exists, limited mesiodistal space exists(less than 5 mm) => a cantilever may be indicated in the anterior region
m.akouchekian

65. Removable Partial Denture
No short- or long-term clinical studies exist in the literature for single anterior tooth replacement with an RPD.
The usual indication :economics
the easiest interim treatment modality during submerged implant healing
Loading of a bone graft with an RPD during initial healing :
increase the risk of micromovement
decrease the success rate of a bone augmentation
Therefore if a bone augmentation is indicated and an RPD is used, it should have a cast framework with occlusal rests to prevent rotation and loading of the soft tissue during function.
m.akouchekian

66. Resin-Bonded Restoration
has a higher survival rate in the maxillary anterior region than any other location in the mouth.
The primary indication:
a transitional restoration during bone and soft tissue grafts before implant placement
m.akouchekian

67. Two modifications:
no enamel preparation exists on the abutment teeth and the metal substructure design is extended in areas of enamel that are gingival to the occlusal contact zones (decreases retention)
An acrylic removable overlay prosthesis, or a flipper is fabricated
m.akouchekian

68. Resin-Bonded Restoration
m.akouchekian

69. Single-Tooth Implant
More clinical studies have been conducted for a maxillary anterior single-tooth replacement with an implant than any other treatment option.
Retrospective reports are available
many prospective clinical studies confirm the data of previous reports
m.akouchekian

70. Single-Tooth Implant
The maxillary anterior single-tooth implant has the highest success rate compared with any other treatment option to replace missing teeth with an implant restoration
recently, a trend toward single-stage and immediate- extraction implants has emerged. This appears especially attractive in the maxillary anterior region, where the soft tissue drape is ideal before the extractionand patients are more anxious to have a fixed replacement.
m.akouchekian

71. Single-Tooth Implant
m.akouchekian

72. Age Limitations a greater soft tissue pocket around the implant
The minimum age of the implant patient is more often a concern for maxillary anterior tooth replacement,especially for congenitally missing teeth
implants:
do not erupt along with adjacent teeth
Do not become secondarily displaced in space as do ankylosed teeth during growth of the jaws
many implants placed in adolescents with residual growth may be in infraposition after 10 years
a greater soft tissue pocket around the implant
Tissue shrinkage
peri-implant conditions
m.akouchekian

73. Age Limitations
The growth of the maxilla occurs in three distinct planes:
transverse (width)
sagittal (length)
vertical
The transverse growth of the anterior maxilla is completed before adolescence
The sagittal growth is the result of growth at the suture and bone apposition in the maxillary tuberosity region
m.akouchekian

74. Age Limitations
The most variable growth of concern is the sagittal growth, because the premaxilla may advance downward and forward or primarily downward
As much as 25% of this displacement is lost as the result of resorption at the anterior =>facial bone resorption of the maxillary implants placed before completionof growth
m.akouchekian

75. Age Limitations
In premaxilla growth should be completed before implant placement.
when cessation of growth and development is undetermined => Multiple implants should not be splinted across the midline in the adolescent.
m.akouchekian

76. Age Limitations
during the growth, teeth shift mesially. between the ages of 10 and 21:
posterior segment (canine to molar): moves anaverage of 5 mm mesially
the anterior segment: moves an average of 2.5 mm
Therefore an implant placed too early in the growthperiod could impede the mesial shift, thus resulting in an asymmetrical arch
m.akouchekian

77. Age Limitations
The vertical growth continues well after transverse and sagittal growth.
The Clinical reports have shown that:
implants in the anterior maxilla at the age of 7 may be located up to 10 mm apically compared with the neighboring teeth 9 years later
solitary implants placed at the age of 12 will be in infraocdusion 5 to 7 mm 4 years later
m.akouchekian

78. Age Limitations As a general rule:
the lateral incisor may be inserted at a younger ge than a central incisor or canine
less obvious to the eye when lateral incisors are at different height positions, compared with central incisors.
It is not unusual for a lateral incisor to be shorter than the adjacent teeth
m.akouchekian

79. Age Limitations
Misch et al have created four guidelines for implants placed in younger patients:
the chronological age of the patient
The chronological age of growth cessation :
for girls from 9 to 15 years and
for boys 11 to 17 years
As a general rule: implant insertion inthe anterior maxilla is delayed:
for female patients untilat least 15 years
male patients until 18 years of age.
However, this guideline is too variable to be used alone => ideally, age is related to the patient's biological age
m.akouchekian

80. Age Limitations endocrine changes size of the the child
The female patient should be able to menstruate
the male patient should have body hair, voice changes
size of the the child
implant patient should have greater height than their same-sex parent
The size of the patient is more important than the age
m.akouchekian

81. Age Limitations the patient has not grown in the last 6- month period
This criterion is easier to observe than cephalograms or hand-wrist films with a 2-year evaluation period.
m.akouchekian

82. Age Limitations
The two criteria that make the implant site most at risk:
a male patient
a central incisor
a delayed growth spurt :
a male patient :4-inch change in height
female patient may grow 1 to 2 inches
If all four criteria are fulfilled (i.e., minimum age, endocrine changes, recent stature growth, 2-year lateral cephalometric radiographs with no changes) => it is very likely the patient has completed their maxillary anterior jaw growth =>the implant may be inserted with little risk or compromise
m.akouchekian

83. Esthetics
the natural central incisor and canine teeth are often larger in their faciopalatal dimension at the CEl than the mesiodistal dimension
The implant is round in cross section
the cervical esthetics of a single-implant crown must accommodate a round-diameter implant and balance hygiene and esthetic parameters
Often a soft tissue model is required to transfer the soft tissue clinical condition to the laboratory. Rarely are these unique needed for a crown on a natural tooth
m.akouchekian

84. Crown Height Space Patients with:
Angle's Class II Division II skeletal patterns
an inadequate maxillornandibular relationship
severe deficiency in the VD
are poor candidates for many treatment options
without prior corrections ,they are contraindicated for dental implants
m.akouchekian

85. Mesiodistal Space The smallest-diameter implant body:3.2 mm
the crest module of these two-piece implants :3.5 mmmor more
the mesiodistal edentulous space for a two-piece implant should be 6.5 mm or greater
The average maxillary lateral incisor is 6.6 mm
patients with congenitally missing teeth often have contralateral anterior teeth narrower than typical=> orthodontic therapy to increase the intra tooth space is inadequate
when the lateral incisor is missing, the root of the adjacent teeth may be angled toward the edentulous site, further decreasing the intratooth bone dimension for implant => Orthodontic treatment to reposition the roots out of the edentulous root space may not be accepted by the patient
m.akouchekian

86. Mesiodistal Space
One-piece dental implants may be fabricated in mm to 3.0-mm diameters to accommodate a reduced mesiodistal dimension criterion
do not have a microgap
the vertical defect is narrower than most two-piece implant systems
they may be placed as close as 1 mm from an adjacent tooth
can accommodate a 5-mm mesiodistal missing tooth space
m.akouchekian

87. Bone Height not only the available bone volume is necessary
The available bone for implant insertion in esthetic regions will greatly influence:
the soft tissue drape
implant size
Implant position (angulation and depth)
The final esthetic outcome
not only the available bone volume is necessary
also the position of the osseous crest is specific
The ideal midcrestal position of the edentulous site:2 mm below the facial CEj of the adjacent teeth
m.akouchekian

88. Bone Height Becker et al. Found:
the interproximal bone:
should be scalloped
3 mm more incisal than the midcrestal position
Becker et al. Found:
the range of interproximal bone height above the midfacial scallop was from less than 2.1 mm to more than 4.1 mm
2.1 mm :flat
2.8 mm : scalloped
4.1 mm :pronounced scalloped
m.akouchekian

89. The flat anatomy => square tooth shape
the scalloped => ovoid tooth shape
pronounced scalloped =>triangular-shaped tooth
However, these relationships do not always exist
When a flat interdental-to-crest dimension is found on triangular teeth => the interproximal space will usually not be filled with soft tissue
because the dimension of the interproximal contact to the bone will be greater than 5 mm.
when a single-tooth site has inadequate bone height at the crest and the adjacent roots also have lost bone =>
Orthodontic extrusion of the teeth may be considered (To grow crestal bone height on the adjacent roots,in relation to the ideal crest of the ridge)
m.akouchekian

90. Faciopalatal Width
Most of the conditions that lead to single-tooth loss result in the loss of some or all of the facial bone
within the first year of tooth loss :a 25% decrease in faciopalatal
within 3 years: a 30% to 40% decrease
After 3 years: it almost never presents adequate available bone for the properly sized implant.
m.akouchekian

91. Faciopalatal Width Because:
the labial plate is very thin compared with the palatal plate
facial undercuts are often found over the roots of the teeth
=> The bone width loss is primarily from the facial region
m.akouchekian

92. Faciopalatal Width
The amount of available bone width (faciopalatal) should be at least 2.0 mm greater than the implant diameter at implant insertion and ideally more than 3 mm greater in width
m.akouchekian

93. Soft Tissue Drape When a tooth is lost:
the thin interseptal bone disappears
the bone remodels in a sloping fashion from the palatal to the more apical facial bony plate
the interdental papillae are often depressed
The use of a soft tissue removable prosthesis often accelerates the collapse of the soft tissue and its apical migration
Soft tissue manipulation to restore their proper contour is often required in conjunction with implant therapy.
m.akouchekian

94. m.akouchekian

95. SPECifiC SINGLE-TOOTH IMPLANT INDICATIONS
Anodontia
The most common maxillary anterior tooth replaced by an implant is a central incisor lost from trauma (e.g.,endodontic failure, fracture, root resorption) and/or a lateral incisor lost as a result of agenesis
in a lateral incisor:
the ideal cervical region of the tooth is similar to the implant diameter
the roots of the adjacent natural teeth often impinge on the edentulous bone
the mesiodistal length is insufficient
orthodontic therapy before implant placement should often be considered
m.akouchekian

96. SPECifiC SINGLE-TOOTH IMPLANT INDICATIONS
When the patient is missing a maxillary lateral incisor, space closure is less often indicated:
When a maxillary canine is orthodontically moved to a lateral position:
The midline between the central incisors is often shifted to the missing tooth side.
The canine eminence over the canine root is positioned under the nose=>creat a depression lateral to the naris, and a less full maxillary lip on one side of the midline.
These differences are more evident as the patient ages
The maxillary canine is larger faciopalatally than mesiodistally => the cervical emergence is different from the contralateral incisor, even when restored with a laminate facing.
The height of gingival contour is also higher than the lateral incisor on the other side of the arch.
m.akouchekian

97. SPECifiC SINGLE-TOOTH IMPLANT INDICATIONS
The missing maxillary lateral incisor is the tooth most often replaced with a dental implant because the other orthodontic or prosthetic options are usually poor alternatives.
m.akouchekian

98. A congenital missing mandibular second premolar
The treatment options are usually different for a mandibular second premolar compared with a maxillary lateral incisor.
A congenital missing mandibular second premolar
the deciduous molar may be extracted patient in 5 to 6 years old.
The permanent first molar may then erupt in a more mesial position
When the first deciduous molar is lost naturally (around the age of 9 to 11 years)
the first permanent premolar and first molar may be orthodontically positioned adjacent to each other
This approach eliminates the need for a second premolar replacement
no required to bone graft, implant surgery, or crown (or combination of these treatments)
Very few disadvantages exist to the use of orthodontics to eliminate this posterior missing tooth space.
m.akouchekian

99. SPECifiC SINGLE-TOOTH IMPLANT INDICATIONS
When the deciduous second molar is maintained:
it often becomes ankylotic
the opposing maxillary second premolar extrudes
the mesiodistal space is larger than the usual premolar(Because the deciduous molar is 1.9 mm larger than a premolar)
The deciduous tooth does not have a buccolingual width of bone => can not use a larger-diameter implant.
The crown for this larger tooth dimension is supported by a regular-size implant, which increases forces on the abutment screw and increases the risk of screw-loosening complications.
m.akouchekian

100. Orthodontic Implant Site Development
In specific situations, the management of the patient in the early treatment phase may require orthodontics before the implant insertion to replace the missing tooth:
Space oppening
congenitally missing teeth
If bone height is insufficient and bone loss is also present on the adjacent teeth
when the patient has a failing tooth
m.akouchekian

101. The maxillary deciduous lateral incisor is prematurely extracted.
Missing lateral incisor in a child before the eruption of the permanent canine, Kokich proposed the following treatment modality:
The maxillary deciduous lateral incisor is prematurely extracted.
The permanent canine is encouraged to erupt in the missing lateral incisor position => the bone around the canine forms in the lateral incisor position.
after the eruption of the permanent canine in the lateral position, The deciduous canine is extracted
The canine is orthodontically retracted into the ideal canine position.
The remaining lateral incisor bone volume is abundant and ideal for an endosteal single-tooth implant.
After growth and development of the child has occurred, an implant may be inserted.
In this manner, a bone graft will not be required before implant
m.akouchekian

102. Root Resorption
Root resorption may cause the loss of a single anterior tooth.
Two major categories of root resorption:
external
Internal
when structural failure is evident and the extraction of the tooth is eminent, two different treatment options related to the type of resorption exist.
Internal root resorption:
The treatment of choice is often orthodontic extraction
m.akouchekian

103. a 3-month extraction process produces sufficient movement
so that the remaining root diameter in the bone is smaller than the implant diameter.
after 3 months of orthodontic extrusion, no void exists around the implant at the time of extraction and implant insertion.
m.akouchekian

104. m.akouchekian

105. Delaying the extraction as long as possible
When external root resorption is the cause of structural failure of the tooth root,
Bone, replacing the root defect
No evidence of a periodontal ligament space around the defect is seen
orthodontic extrusion is not possible
Delaying the extraction as long as possible
the remaining root segments may be cored out during the implant osteotomy procedure
If the surgical defect is too large for immediate implant insertion, then the osteotomy is grafted and the implant procedure is delayed.
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106. Remaining Maxillary Anterior Teeth
to obtain an ideal result When the maxillary incisor single-tooth replacement:
not only evaluate the edentulous site but also the remaining anterior teeth
the adjacent teeth most often dictate its length, contour, shape, and position
The patient, once fully informed of the existing discrepancies and their potential negative effect on the envisioned result, may decide to:
address and correct the existing problems of the adjacent teeth
simply elect to accept the compromise
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107. Tooth Size The two maxillary central incisors should
appear symmetrical and of similar size
when the missing tooth is a central incisor with a mesiodistal space less or more than the size of the corresponding central incisor:
Orthodontic correction is strongly encouraged
modify the existing central incisor with a veneer to make it similar in size and shape to the missing tooth restoration
lowering the mesial interproximal contact
Making the two centrals more square shaped
Decreases the height requirement of the papilla
The shades of the two centrals are also easier to match when made at the same time in the laboratory.
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108. Tooth Size
Because the clinical crown height of an implant supported central incisor is often longer than the adjacent tooth, an esthetic crown lengthening on the natural tooth may be used to align the gingival margins
a crown-lengthening procedure on the natural tooth, may be more predictable than attempting to cover the implant crown with soft tissue
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109. Tooth Shape Three basic shapes of maxillary anterior teeth exist:
square
ovoid
Triangular
The tooth shape will influence the interproximal contact and the gingival embrasure.
The square tooth shape is the most favorable to obtain an ideal soft tissue drape and papillae around the crown
the interproximal contact is more apical
more tooth structure fills the interproximal region
a triangular tooth shape has
a more incisal interproximal contact
a steeper gingival scallop
farther from the interproximal bone
a space often exists between the interproximal contact and the interdental papilla of the remaining teeth
When the soft tissue fills the interproximal space of the remaining anterior teeth that have a triangular shape, the tissues may be very liable and easily vanish during the healing phases after implant surgery.
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110. Tooth Shape
The tooth shape also affects the topography of the underlying hard tissues.
The roots of triangular tooth shapes are positioned farther apart :
Have thicker facial and interproximal bone
Decrease the amount of crestal bone loss after an extraction
the prognosis for an immediate implant insertion is more favorable
provide the recommended 1.5 mm or more of interproximal bone from the adjacent tooth
The square shaped tooth:
have less interproximal bone between the roots
a greater risk of crestal or interproximal bone loss with an immediate implant insertion
less favorable for immediate implant insertion after extraction.
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111. Soft Tissue Drape
The height of the maxillary lip when smiling (high lip line) is one of me most important criterion to evaluate when observing me cervical region of the maxillary anterior teeth.
Ideally:
the height of the maxillary lip should rest at the junction of the free gingival margin on the facial aspect of the maxillary centrals and canine teeth => the interdental papillae are visible, but little gingival display is seen over the clinical crowns.
Almost 70% of patients have this ideal smile position.
A "gummy"smile displays more than 2 mm of soft tissue above the clinical maxillary crowns and is more acceptable in the female patient.
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112. Soft Tissue Drape
Under ideal conditions in the maxillary anterior region:
interproximal contact should begin in the incisal third
the bone:
In midfacial: 2 mm below the CEl
in the interproximal region : 3 mm more incisal the CEl
The soft tissue:
In midfacial :3 mm above the bone at the midfacial position (1 mm above the CEl)
in the interproximal region : 3 to 5 mm above the interproximal bone
Therefore if the interproximal contact is within 3 to 5 mm of the interproximal bone, then the interdental papilla will most often completely fill the space
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113. Soft Tissue Drape The higher the gingival scallop:
the higher the risk for gingival loss after extraction
the less likely the surgical and restorative procedures will be able to restore an ideal soft tissue contour
a flatter gingival scallop:
minimal tissue shrinkage
more ideal outcome
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114. Soft Tissue Drape
The biotype of the gingiva is usually called thick or thin.
Thicker tissue:
more resistant to the shrinkage or recession
more often leads to the formation of a periodontal pocket after bone loss.
Thin gingival tissues:
more prone to shrinkage after tooth extraction
more difficult to elevate or augment after tooth loss.
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115. Soft Tissue Drape According to Kois:
predictability of the maxillary anterior single-tooth implant is ultimately determined by the patient's own presenting anatomy.
Favorable conditions include:
when the tooth position is more coronal relative to the full gingival margin
square tooth shapes
flat scallop periodontium forms
thick periodontium biotypes, and
high (<3 mm) facial osseous crest positions of the teeth and midcrestal
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116. Soft Tissue Drape Unfavorable patient anatomy :
aligned or apical preexisting tooth (relative to the free gingival margin)
Triangular tooth shapes
high scallop periodontium form
thin periodontium types
low (>4 mm) facial osseous crest positions in relation to adjacent teeth and midcrestal
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117. IMPLANT CREST MODULE DESIGN
The two most common complications of anterior singletooth implant replacement:
abutment screw loosening
crestal bone loss
Both of these conditions are in part related to the implant crest module design
to decrease in abutment screw loosening: an antirotational feature
to decrease crestal bone loss:
The crest module of an implant body should also be designed to transmit some compression and tensile forces to the crestal bone.
Smooth metal on the crest module transmits shear forces to the bone => increases the crestal bone loss
smooth metal collars on the implant crest module should be limited to approximately 0.5 mm
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118. Implant Size
the implant body should obviously not be as wide as the natural tooth or clinical crown=>the emergence contour and interdental papillae region cannot be properly established.
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119. Implant Size
The ideal width of bone would allow at least 1.5 mm on the facial aspect of the implant
if a vertical defect forms around the crest module, that defect would not become horizontal and change the cervical contour of the facial gingiva
the faciopalatal width dimension is not as critical on the palatal aspect of the implant
the palatal bone is dense cortical bone and more resistant to bone loss
the palatal area is not within the esthetic zone
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120. Thanks for your attention 
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