Choosing the Appropriate Implant Modality Chapter 16 Dental Notes | EduRev

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Dental : Choosing the Appropriate Implant Modality Chapter 16 Dental Notes | EduRev

 Page 1


Chapter 16 –  Choosing the Appropriate Implant Modality  
The three professionally accepted abutment-providing modalities covered in the teaching case 
chapters are safe and effective for their intended purpose of providing abutment support, and are 
sufficiently technique-permissive to be incorporated into the normal routine of most practitioners. 
Whereas each is known to be scientifically acceptable in terms of safety and efficacy,
[1][2][3][4][5][6]
 
the three differ markedly with regard to the clinical criteria for professional acceptance described 
in Chapter 7 . This affects diagnosis and patient acceptance. 
In most cases properly diagnosed for mainstream treatment, one of the modalities presents itself 
as being the most appropriate for treatment in consideration of the preoperative volume of 
available bone. In some cases, for example, only the plate/blade form modality can be used for 
mainstream treatment, because available bone is insufficient for root form placement
[7]
 and 
overabundant available bone precludes subperiosteal implant placement. For other patients, only 
the subperiosteal implant may be applicable, because a lack of available bone rules out use of 
any endosteal modality without extensive non-mainstream bone augmentation procedures.
[8][9]
  
In cases in which available bone is sufficient for use of the root form modality, plate/blade forms 
may also be used. Because of frequent lack of adequate available bone depth posteriorly, 
conventional root forms can be used in approximately half of the cases that present for 
mainstream treatment. The Innova Endopore implant used in the posterior partial edentulism 
teaching case presented in Chapter 11 increases the applicability of the root form modality, 
because its diffusion-bonded microsphere interface increases its surface area to the extent that it 
can be approximately two thirds the depth of a conventional root form.
[10]
 These considerations 
reaffirm the diagnostic importance of accurately quantifying available bone, in all its variations, 
because of its profound effect on treatment planning and implant modality selection. It is precisely 
because no one implant modality can be used for the mainstream treatment of every case that 
practicing multimodal implant dentistry is of benefit to the practitioner and patient alike. 
This chapter demonstrates how available bone governs much of diagnosis in implant dentistry. 
Available bone requirements are quantified for mainstream treatment using each modality, 
allowing one to empirically determine if any given modality is applicable to the case at hand. In 
the presence of insufficient or overabundant bone, when one modality cannot be considered for 
mainstream treatment, another one can. In cases of overlap, more than one modality is 
appropriate for the available bone presented. Scientifically, the overlapping modalities are equally 
valid, insofar as each can safely and effectively provide additional abutment support for 
restorative dentistry. In such cases, one should apply the clinical criteria for an ideal implant 
system, provided in Chapter 7 , to the modalities under consideration. If two modalities can be 
used safely and effectively, considerations such as time, esthetics, cost, complexity, and trauma 
become important, and can guide the practitioner to make the decision that most benefits the 
patient.
[11]
  
The broader message of this chapter is that the combined scope of treatment using all three 
abutment-providing modalities—the multimodal approach—is far greater than the scope of 
treatment exclusively using any one modality. Collectively, the use of these three modalities 
represents the true scope of treatment possibilities afforded by implant dentistry.
[12]
 Every 
practitioner should understand the indications and contraindications of each modality, and share 
this understanding with patients considering treatment. 
DETERMINING WHETHER IMPLANT TREATMENT CAN SUCCEED  
Determining whether implant treatment can succeed is one of the most important concepts in 
implant dentistry, and is a consideration that must be incorporated into the diagnosis and 
Page 2


Chapter 16 –  Choosing the Appropriate Implant Modality  
The three professionally accepted abutment-providing modalities covered in the teaching case 
chapters are safe and effective for their intended purpose of providing abutment support, and are 
sufficiently technique-permissive to be incorporated into the normal routine of most practitioners. 
Whereas each is known to be scientifically acceptable in terms of safety and efficacy,
[1][2][3][4][5][6]
 
the three differ markedly with regard to the clinical criteria for professional acceptance described 
in Chapter 7 . This affects diagnosis and patient acceptance. 
In most cases properly diagnosed for mainstream treatment, one of the modalities presents itself 
as being the most appropriate for treatment in consideration of the preoperative volume of 
available bone. In some cases, for example, only the plate/blade form modality can be used for 
mainstream treatment, because available bone is insufficient for root form placement
[7]
 and 
overabundant available bone precludes subperiosteal implant placement. For other patients, only 
the subperiosteal implant may be applicable, because a lack of available bone rules out use of 
any endosteal modality without extensive non-mainstream bone augmentation procedures.
[8][9]
  
In cases in which available bone is sufficient for use of the root form modality, plate/blade forms 
may also be used. Because of frequent lack of adequate available bone depth posteriorly, 
conventional root forms can be used in approximately half of the cases that present for 
mainstream treatment. The Innova Endopore implant used in the posterior partial edentulism 
teaching case presented in Chapter 11 increases the applicability of the root form modality, 
because its diffusion-bonded microsphere interface increases its surface area to the extent that it 
can be approximately two thirds the depth of a conventional root form.
[10]
 These considerations 
reaffirm the diagnostic importance of accurately quantifying available bone, in all its variations, 
because of its profound effect on treatment planning and implant modality selection. It is precisely 
because no one implant modality can be used for the mainstream treatment of every case that 
practicing multimodal implant dentistry is of benefit to the practitioner and patient alike. 
This chapter demonstrates how available bone governs much of diagnosis in implant dentistry. 
Available bone requirements are quantified for mainstream treatment using each modality, 
allowing one to empirically determine if any given modality is applicable to the case at hand. In 
the presence of insufficient or overabundant bone, when one modality cannot be considered for 
mainstream treatment, another one can. In cases of overlap, more than one modality is 
appropriate for the available bone presented. Scientifically, the overlapping modalities are equally 
valid, insofar as each can safely and effectively provide additional abutment support for 
restorative dentistry. In such cases, one should apply the clinical criteria for an ideal implant 
system, provided in Chapter 7 , to the modalities under consideration. If two modalities can be 
used safely and effectively, considerations such as time, esthetics, cost, complexity, and trauma 
become important, and can guide the practitioner to make the decision that most benefits the 
patient.
[11]
  
The broader message of this chapter is that the combined scope of treatment using all three 
abutment-providing modalities—the multimodal approach—is far greater than the scope of 
treatment exclusively using any one modality. Collectively, the use of these three modalities 
represents the true scope of treatment possibilities afforded by implant dentistry.
[12]
 Every 
practitioner should understand the indications and contraindications of each modality, and share 
this understanding with patients considering treatment. 
DETERMINING WHETHER IMPLANT TREATMENT CAN SUCCEED  
Determining whether implant treatment can succeed is one of the most important concepts in 
implant dentistry, and is a consideration that must be incorporated into the diagnosis and 
treatment planning routine of every implant dentistry practitioner in every case. If a dental implant 
of any kind is placed successfully into or onto the available bone, heals properly, and is fitted with 
its final prosthesis, will it be able to withstand the anticipated load? Can it do the job asked of it? 
Just because an implant can be placed and heal successfully does not mean that it will be able to 
withstand the forces to which it will be subjected. Not every implant configuration can support an 
equal load long-term in health. The various implant configurations exist to advantageously use 
the various volumes and configurations of available bone one encounters in candidate implant 
dentistry patients. 
If it is deemed likely that an implant considered for use in a case would not remain in health long-
term, the treatment plan should be changed, or the case may fail. This is the same consideration 
applied to evaluate potential natural abutments in conventional prosthodontics, in that sometimes 
a natural tooth available for abutment support may be deemed unable to bear the load in health 
long-term, and therefore is avoided or splinted to other teeth. 
In a way, asking an entry-level practitioner to make this determination is premature. Realistically, 
one cannot accurately determine how much load an implant should be able to withstand until one 
has gained experience observing the course of several mainstream cases. Generally, if one 
follows the guidelines established in Chapter 1 to determine whether a case is mainstream, an 
implant appropriate for the available bone will be able to withstand the anticipated load. Cases 
similar to the teaching cases discussed in the step-by-step procedure chapters should succeed. 
However, in any type of case, including the most predictable of mainstream cases, it is important 
to be sure that one is asking the implants to do a realistic job. The case must not be 
underengineered. This consideration gains in importance as one progresses toward treating 
intermediate and advanced cases, in which the capability of the implants to withstand anticipated 
load cannot be taken for granted. Proper case engineering is essential. In intermediate and 
advanced cases, the judgment of the practitioner has a greater influence on the ultimate outcome 
of the case. 
In addition to evaluating available bone, the practitioner must consider the nature of the patient. Is 
the patient a gentle, weak, or aged person, or a vigorous person and a habitual bruxer? Other 
factors such as the opposing dentition must also be taken into consideration. For example, an 
opposing removable denture affords more shock absorption than natural teeth and therefore will 
impart less force to the implant-supported prosthesis. Proper occlusion is also an important 
consideration 
AVAILABLE BONE AS THE PRIMARY DIAGNOSTIC CONSIDERATION  
Mainstream Cases Use Existing Available Bone  
Mainstream cases use the available bone that exists preoperatively. It is a fundamental precept of 
mainstream implant dentistry that the implant should be selected to fit the anatomy and volume of 
the available bone, and that the available bone should not need to be altered or augmented 
substantially to accommodate a specific implant modality. As discussed in Chapter 15 , bone 
enhancement techniques can change the anatomy of the alveolar ridge, sometimes radically. 
However, such techniques are not considered mainstream because of the complexity of 
treatment, insufficient long-term success and survival data, and lack of general consensus on 
preferred materials and methods of placement for different types of treatment. The prognostic 
value of altering an alveolar ridge to fit a preselected implant modality or configuration is 
questionable. It is certainly easier to select an implant that fits the available bone as presented. 
Abundant long-term success and survival data support such a course of action. Chapter 8 
presents some of these data. 
Page 3


Chapter 16 –  Choosing the Appropriate Implant Modality  
The three professionally accepted abutment-providing modalities covered in the teaching case 
chapters are safe and effective for their intended purpose of providing abutment support, and are 
sufficiently technique-permissive to be incorporated into the normal routine of most practitioners. 
Whereas each is known to be scientifically acceptable in terms of safety and efficacy,
[1][2][3][4][5][6]
 
the three differ markedly with regard to the clinical criteria for professional acceptance described 
in Chapter 7 . This affects diagnosis and patient acceptance. 
In most cases properly diagnosed for mainstream treatment, one of the modalities presents itself 
as being the most appropriate for treatment in consideration of the preoperative volume of 
available bone. In some cases, for example, only the plate/blade form modality can be used for 
mainstream treatment, because available bone is insufficient for root form placement
[7]
 and 
overabundant available bone precludes subperiosteal implant placement. For other patients, only 
the subperiosteal implant may be applicable, because a lack of available bone rules out use of 
any endosteal modality without extensive non-mainstream bone augmentation procedures.
[8][9]
  
In cases in which available bone is sufficient for use of the root form modality, plate/blade forms 
may also be used. Because of frequent lack of adequate available bone depth posteriorly, 
conventional root forms can be used in approximately half of the cases that present for 
mainstream treatment. The Innova Endopore implant used in the posterior partial edentulism 
teaching case presented in Chapter 11 increases the applicability of the root form modality, 
because its diffusion-bonded microsphere interface increases its surface area to the extent that it 
can be approximately two thirds the depth of a conventional root form.
[10]
 These considerations 
reaffirm the diagnostic importance of accurately quantifying available bone, in all its variations, 
because of its profound effect on treatment planning and implant modality selection. It is precisely 
because no one implant modality can be used for the mainstream treatment of every case that 
practicing multimodal implant dentistry is of benefit to the practitioner and patient alike. 
This chapter demonstrates how available bone governs much of diagnosis in implant dentistry. 
Available bone requirements are quantified for mainstream treatment using each modality, 
allowing one to empirically determine if any given modality is applicable to the case at hand. In 
the presence of insufficient or overabundant bone, when one modality cannot be considered for 
mainstream treatment, another one can. In cases of overlap, more than one modality is 
appropriate for the available bone presented. Scientifically, the overlapping modalities are equally 
valid, insofar as each can safely and effectively provide additional abutment support for 
restorative dentistry. In such cases, one should apply the clinical criteria for an ideal implant 
system, provided in Chapter 7 , to the modalities under consideration. If two modalities can be 
used safely and effectively, considerations such as time, esthetics, cost, complexity, and trauma 
become important, and can guide the practitioner to make the decision that most benefits the 
patient.
[11]
  
The broader message of this chapter is that the combined scope of treatment using all three 
abutment-providing modalities—the multimodal approach—is far greater than the scope of 
treatment exclusively using any one modality. Collectively, the use of these three modalities 
represents the true scope of treatment possibilities afforded by implant dentistry.
[12]
 Every 
practitioner should understand the indications and contraindications of each modality, and share 
this understanding with patients considering treatment. 
DETERMINING WHETHER IMPLANT TREATMENT CAN SUCCEED  
Determining whether implant treatment can succeed is one of the most important concepts in 
implant dentistry, and is a consideration that must be incorporated into the diagnosis and 
treatment planning routine of every implant dentistry practitioner in every case. If a dental implant 
of any kind is placed successfully into or onto the available bone, heals properly, and is fitted with 
its final prosthesis, will it be able to withstand the anticipated load? Can it do the job asked of it? 
Just because an implant can be placed and heal successfully does not mean that it will be able to 
withstand the forces to which it will be subjected. Not every implant configuration can support an 
equal load long-term in health. The various implant configurations exist to advantageously use 
the various volumes and configurations of available bone one encounters in candidate implant 
dentistry patients. 
If it is deemed likely that an implant considered for use in a case would not remain in health long-
term, the treatment plan should be changed, or the case may fail. This is the same consideration 
applied to evaluate potential natural abutments in conventional prosthodontics, in that sometimes 
a natural tooth available for abutment support may be deemed unable to bear the load in health 
long-term, and therefore is avoided or splinted to other teeth. 
In a way, asking an entry-level practitioner to make this determination is premature. Realistically, 
one cannot accurately determine how much load an implant should be able to withstand until one 
has gained experience observing the course of several mainstream cases. Generally, if one 
follows the guidelines established in Chapter 1 to determine whether a case is mainstream, an 
implant appropriate for the available bone will be able to withstand the anticipated load. Cases 
similar to the teaching cases discussed in the step-by-step procedure chapters should succeed. 
However, in any type of case, including the most predictable of mainstream cases, it is important 
to be sure that one is asking the implants to do a realistic job. The case must not be 
underengineered. This consideration gains in importance as one progresses toward treating 
intermediate and advanced cases, in which the capability of the implants to withstand anticipated 
load cannot be taken for granted. Proper case engineering is essential. In intermediate and 
advanced cases, the judgment of the practitioner has a greater influence on the ultimate outcome 
of the case. 
In addition to evaluating available bone, the practitioner must consider the nature of the patient. Is 
the patient a gentle, weak, or aged person, or a vigorous person and a habitual bruxer? Other 
factors such as the opposing dentition must also be taken into consideration. For example, an 
opposing removable denture affords more shock absorption than natural teeth and therefore will 
impart less force to the implant-supported prosthesis. Proper occlusion is also an important 
consideration 
AVAILABLE BONE AS THE PRIMARY DIAGNOSTIC CONSIDERATION  
Mainstream Cases Use Existing Available Bone  
Mainstream cases use the available bone that exists preoperatively. It is a fundamental precept of 
mainstream implant dentistry that the implant should be selected to fit the anatomy and volume of 
the available bone, and that the available bone should not need to be altered or augmented 
substantially to accommodate a specific implant modality. As discussed in Chapter 15 , bone 
enhancement techniques can change the anatomy of the alveolar ridge, sometimes radically. 
However, such techniques are not considered mainstream because of the complexity of 
treatment, insufficient long-term success and survival data, and lack of general consensus on 
preferred materials and methods of placement for different types of treatment. The prognostic 
value of altering an alveolar ridge to fit a preselected implant modality or configuration is 
questionable. It is certainly easier to select an implant that fits the available bone as presented. 
Abundant long-term success and survival data support such a course of action. Chapter 8 
presents some of these data. 
Range of Available Bone Volume Suitable for Each Implant Modality  
This section analyzes the available bone that is typically required for each of the abutment-
providing modalities, dimension by dimension, and identifies the conditions in which only one 
modality can fit the available bone to provide mainstream treatment. 
Root Forms.  
The ideal available bone parameters for a typical conventional root form configuration are shown 
in Box 16-1 . No available bone presentations exist for which only the root form modality can be 
used to provide mainstream treatment.  
Box 16-1  
IDEAL AVAILABLE BONE PARAMETERS FOR A ROOT FORM WITH 4-MM DIAMETER 
AND 10-MM DEPTH  
 
    Bucco/labio-lingual width: 6 mm 
    Mesio-distal length: 8 mm 
    Depth: 12 mm 
 
Bucco/Labio-Lingual Available Bone Width.  
The width of a root form implant is its diameter. It is best to have 1 mm of crestal bone width at 
the bucco/labiolingual borders of any endosteal implant on the day of insertion. Three-
dimensional finite element analysis in conjunction with clinical observation indicates that this is 
generally the minimum amount of investing bucco/ labio-lingual bone required at the ridge crest to 
absorb functional loads within physiologic limits of health.
[13]
 The reason that the amount of 
required investing bone at the ridge crest is smaller than in other areas is because cortical bone 
offers more support. Clinically, in mainstream cases, this means that a conventional root form 
implant with a diameter of 4 mm requires a pretreatment ridge width of 6 mm as measured 1 to 2 
mm apical to the ridge crest. 
Mesio-Distal Available Bone Length.  
Because a root form is round in cross section, its length is its diameter. If a root form is inserted 
adjacent to a tooth or another root form, a minimum of 2 mm of clearance between them is 
recommended in mainstream cases. This amount of proximal bone is required because the 
mesial and distal of the implant interface is almost entirely against cancellous bone. There is a 
much higher percentage of cortical contact against the buccal/labial and lingual interfaces.
[14]
  
Available Bone Depth.  
Conventional root forms used for mainstream implant dentistry treatment are typically 10 mm 
deep. It is advised to have approximately 2 mm of clearance beyond the apical end of the implant 
to the nearest landmark. Thus, for conventional root forms, 12 mm of available bone depth is 
generally recommended. It is permissible to reduce the height of the ridge crest to create the 
sufficient ridge width provided that in doing so a sufficient depth of available bone remains from 
the reduced crest to the nearest landmark to place the implant with 2 mm of clearance. 
Plate/Blade Forms.  
Page 4


Chapter 16 –  Choosing the Appropriate Implant Modality  
The three professionally accepted abutment-providing modalities covered in the teaching case 
chapters are safe and effective for their intended purpose of providing abutment support, and are 
sufficiently technique-permissive to be incorporated into the normal routine of most practitioners. 
Whereas each is known to be scientifically acceptable in terms of safety and efficacy,
[1][2][3][4][5][6]
 
the three differ markedly with regard to the clinical criteria for professional acceptance described 
in Chapter 7 . This affects diagnosis and patient acceptance. 
In most cases properly diagnosed for mainstream treatment, one of the modalities presents itself 
as being the most appropriate for treatment in consideration of the preoperative volume of 
available bone. In some cases, for example, only the plate/blade form modality can be used for 
mainstream treatment, because available bone is insufficient for root form placement
[7]
 and 
overabundant available bone precludes subperiosteal implant placement. For other patients, only 
the subperiosteal implant may be applicable, because a lack of available bone rules out use of 
any endosteal modality without extensive non-mainstream bone augmentation procedures.
[8][9]
  
In cases in which available bone is sufficient for use of the root form modality, plate/blade forms 
may also be used. Because of frequent lack of adequate available bone depth posteriorly, 
conventional root forms can be used in approximately half of the cases that present for 
mainstream treatment. The Innova Endopore implant used in the posterior partial edentulism 
teaching case presented in Chapter 11 increases the applicability of the root form modality, 
because its diffusion-bonded microsphere interface increases its surface area to the extent that it 
can be approximately two thirds the depth of a conventional root form.
[10]
 These considerations 
reaffirm the diagnostic importance of accurately quantifying available bone, in all its variations, 
because of its profound effect on treatment planning and implant modality selection. It is precisely 
because no one implant modality can be used for the mainstream treatment of every case that 
practicing multimodal implant dentistry is of benefit to the practitioner and patient alike. 
This chapter demonstrates how available bone governs much of diagnosis in implant dentistry. 
Available bone requirements are quantified for mainstream treatment using each modality, 
allowing one to empirically determine if any given modality is applicable to the case at hand. In 
the presence of insufficient or overabundant bone, when one modality cannot be considered for 
mainstream treatment, another one can. In cases of overlap, more than one modality is 
appropriate for the available bone presented. Scientifically, the overlapping modalities are equally 
valid, insofar as each can safely and effectively provide additional abutment support for 
restorative dentistry. In such cases, one should apply the clinical criteria for an ideal implant 
system, provided in Chapter 7 , to the modalities under consideration. If two modalities can be 
used safely and effectively, considerations such as time, esthetics, cost, complexity, and trauma 
become important, and can guide the practitioner to make the decision that most benefits the 
patient.
[11]
  
The broader message of this chapter is that the combined scope of treatment using all three 
abutment-providing modalities—the multimodal approach—is far greater than the scope of 
treatment exclusively using any one modality. Collectively, the use of these three modalities 
represents the true scope of treatment possibilities afforded by implant dentistry.
[12]
 Every 
practitioner should understand the indications and contraindications of each modality, and share 
this understanding with patients considering treatment. 
DETERMINING WHETHER IMPLANT TREATMENT CAN SUCCEED  
Determining whether implant treatment can succeed is one of the most important concepts in 
implant dentistry, and is a consideration that must be incorporated into the diagnosis and 
treatment planning routine of every implant dentistry practitioner in every case. If a dental implant 
of any kind is placed successfully into or onto the available bone, heals properly, and is fitted with 
its final prosthesis, will it be able to withstand the anticipated load? Can it do the job asked of it? 
Just because an implant can be placed and heal successfully does not mean that it will be able to 
withstand the forces to which it will be subjected. Not every implant configuration can support an 
equal load long-term in health. The various implant configurations exist to advantageously use 
the various volumes and configurations of available bone one encounters in candidate implant 
dentistry patients. 
If it is deemed likely that an implant considered for use in a case would not remain in health long-
term, the treatment plan should be changed, or the case may fail. This is the same consideration 
applied to evaluate potential natural abutments in conventional prosthodontics, in that sometimes 
a natural tooth available for abutment support may be deemed unable to bear the load in health 
long-term, and therefore is avoided or splinted to other teeth. 
In a way, asking an entry-level practitioner to make this determination is premature. Realistically, 
one cannot accurately determine how much load an implant should be able to withstand until one 
has gained experience observing the course of several mainstream cases. Generally, if one 
follows the guidelines established in Chapter 1 to determine whether a case is mainstream, an 
implant appropriate for the available bone will be able to withstand the anticipated load. Cases 
similar to the teaching cases discussed in the step-by-step procedure chapters should succeed. 
However, in any type of case, including the most predictable of mainstream cases, it is important 
to be sure that one is asking the implants to do a realistic job. The case must not be 
underengineered. This consideration gains in importance as one progresses toward treating 
intermediate and advanced cases, in which the capability of the implants to withstand anticipated 
load cannot be taken for granted. Proper case engineering is essential. In intermediate and 
advanced cases, the judgment of the practitioner has a greater influence on the ultimate outcome 
of the case. 
In addition to evaluating available bone, the practitioner must consider the nature of the patient. Is 
the patient a gentle, weak, or aged person, or a vigorous person and a habitual bruxer? Other 
factors such as the opposing dentition must also be taken into consideration. For example, an 
opposing removable denture affords more shock absorption than natural teeth and therefore will 
impart less force to the implant-supported prosthesis. Proper occlusion is also an important 
consideration 
AVAILABLE BONE AS THE PRIMARY DIAGNOSTIC CONSIDERATION  
Mainstream Cases Use Existing Available Bone  
Mainstream cases use the available bone that exists preoperatively. It is a fundamental precept of 
mainstream implant dentistry that the implant should be selected to fit the anatomy and volume of 
the available bone, and that the available bone should not need to be altered or augmented 
substantially to accommodate a specific implant modality. As discussed in Chapter 15 , bone 
enhancement techniques can change the anatomy of the alveolar ridge, sometimes radically. 
However, such techniques are not considered mainstream because of the complexity of 
treatment, insufficient long-term success and survival data, and lack of general consensus on 
preferred materials and methods of placement for different types of treatment. The prognostic 
value of altering an alveolar ridge to fit a preselected implant modality or configuration is 
questionable. It is certainly easier to select an implant that fits the available bone as presented. 
Abundant long-term success and survival data support such a course of action. Chapter 8 
presents some of these data. 
Range of Available Bone Volume Suitable for Each Implant Modality  
This section analyzes the available bone that is typically required for each of the abutment-
providing modalities, dimension by dimension, and identifies the conditions in which only one 
modality can fit the available bone to provide mainstream treatment. 
Root Forms.  
The ideal available bone parameters for a typical conventional root form configuration are shown 
in Box 16-1 . No available bone presentations exist for which only the root form modality can be 
used to provide mainstream treatment.  
Box 16-1  
IDEAL AVAILABLE BONE PARAMETERS FOR A ROOT FORM WITH 4-MM DIAMETER 
AND 10-MM DEPTH  
 
    Bucco/labio-lingual width: 6 mm 
    Mesio-distal length: 8 mm 
    Depth: 12 mm 
 
Bucco/Labio-Lingual Available Bone Width.  
The width of a root form implant is its diameter. It is best to have 1 mm of crestal bone width at 
the bucco/labiolingual borders of any endosteal implant on the day of insertion. Three-
dimensional finite element analysis in conjunction with clinical observation indicates that this is 
generally the minimum amount of investing bucco/ labio-lingual bone required at the ridge crest to 
absorb functional loads within physiologic limits of health.
[13]
 The reason that the amount of 
required investing bone at the ridge crest is smaller than in other areas is because cortical bone 
offers more support. Clinically, in mainstream cases, this means that a conventional root form 
implant with a diameter of 4 mm requires a pretreatment ridge width of 6 mm as measured 1 to 2 
mm apical to the ridge crest. 
Mesio-Distal Available Bone Length.  
Because a root form is round in cross section, its length is its diameter. If a root form is inserted 
adjacent to a tooth or another root form, a minimum of 2 mm of clearance between them is 
recommended in mainstream cases. This amount of proximal bone is required because the 
mesial and distal of the implant interface is almost entirely against cancellous bone. There is a 
much higher percentage of cortical contact against the buccal/labial and lingual interfaces.
[14]
  
Available Bone Depth.  
Conventional root forms used for mainstream implant dentistry treatment are typically 10 mm 
deep. It is advised to have approximately 2 mm of clearance beyond the apical end of the implant 
to the nearest landmark. Thus, for conventional root forms, 12 mm of available bone depth is 
generally recommended. It is permissible to reduce the height of the ridge crest to create the 
sufficient ridge width provided that in doing so a sufficient depth of available bone remains from 
the reduced crest to the nearest landmark to place the implant with 2 mm of clearance. 
Plate/Blade Forms.  
The ideal available bone parameters for a typical plate/blade form configuration are shown in Box 
16-2 . When evaluating available bone for insertion of a plate/blade form implant, it is useful to 
know that in general, an inverse relationship exists between the implant’s length and depth. A 
longer configuration requires less depth to function within physiologic limits of health long-term, 
whereas a configuration that is shorter mesio-distally requires greater depth.  
Box 16-2  
IDEAL AVAILABLE BONE PARAMETERS FOR A PLATE/BLADE FORM WITH 18-MM 
LENGTH AND 8-MM DEPTH  
 
    Bucco/labio-lingual width: 3.35 mm 
    Mesio-distal length: 22 mm 
    Depth: 10 mm 
 
The plate/blade form is the only modality that can provide mainstream treatment in cases within 
certain ranges of available bone depth and width. 
Bucco/Labio-Lingual Available Bone Width.  
Most plate/blade forms are 1.2 to 1.35 mm in width. Thus, with 1 mm as the minimum required 
width of investing bone buccally and lingually, the minimum ridge width for insertion of a 
plate/blade form in a mainstream case is 3.35 mm as measured 1 to 2 mm below the crest. This 
relatively small width requirement is the primary reason that plate/blade forms have such wide 
diagnostic applicability. 
In cases with sufficient depth of available bone for the insertion of an endosteal implant but width 
less than 6 mm, the plate/blade form modality is indicated. 
Mesio-Distal Available Bone Length.  
A minimum of approximately 2 mm of clearance should exist between the mesial or distal border 
of a plate/blade form and an adjacent tooth root or other implant. 
Available Bone Depth.  
Using any plate/blade form configuration, 2 mm of clearance is ideal between the implant and any 
landmarks beyond its depth. In mainstream cases, ridge crest height rarely needs to be reduced 
to create the sufficient ridge width of 3.35 mm. In cases in which depth of available bone is 6 to 
10 mm, the plate/blade form modality is usually the only modality indicated. 
Subperiosteal Implants.  
The maximum available bone parameters for placement of a subperiosteal implant are shown in 
Box 16-3 . Whereas in endosteal implant dentistry insufficient available bone can contraindicate 
the use of a configuration, in subperiosteal implant dentistry overabundant alveolar bone is a 
contraindicating factor. Therefore, whereas in endosteal implant dentistry minimum available 
bone requirements are considered, in subperiosteal implantology the maximum available bone 
that allows a satisfactory prognosis is considered.  
Page 5


Chapter 16 –  Choosing the Appropriate Implant Modality  
The three professionally accepted abutment-providing modalities covered in the teaching case 
chapters are safe and effective for their intended purpose of providing abutment support, and are 
sufficiently technique-permissive to be incorporated into the normal routine of most practitioners. 
Whereas each is known to be scientifically acceptable in terms of safety and efficacy,
[1][2][3][4][5][6]
 
the three differ markedly with regard to the clinical criteria for professional acceptance described 
in Chapter 7 . This affects diagnosis and patient acceptance. 
In most cases properly diagnosed for mainstream treatment, one of the modalities presents itself 
as being the most appropriate for treatment in consideration of the preoperative volume of 
available bone. In some cases, for example, only the plate/blade form modality can be used for 
mainstream treatment, because available bone is insufficient for root form placement
[7]
 and 
overabundant available bone precludes subperiosteal implant placement. For other patients, only 
the subperiosteal implant may be applicable, because a lack of available bone rules out use of 
any endosteal modality without extensive non-mainstream bone augmentation procedures.
[8][9]
  
In cases in which available bone is sufficient for use of the root form modality, plate/blade forms 
may also be used. Because of frequent lack of adequate available bone depth posteriorly, 
conventional root forms can be used in approximately half of the cases that present for 
mainstream treatment. The Innova Endopore implant used in the posterior partial edentulism 
teaching case presented in Chapter 11 increases the applicability of the root form modality, 
because its diffusion-bonded microsphere interface increases its surface area to the extent that it 
can be approximately two thirds the depth of a conventional root form.
[10]
 These considerations 
reaffirm the diagnostic importance of accurately quantifying available bone, in all its variations, 
because of its profound effect on treatment planning and implant modality selection. It is precisely 
because no one implant modality can be used for the mainstream treatment of every case that 
practicing multimodal implant dentistry is of benefit to the practitioner and patient alike. 
This chapter demonstrates how available bone governs much of diagnosis in implant dentistry. 
Available bone requirements are quantified for mainstream treatment using each modality, 
allowing one to empirically determine if any given modality is applicable to the case at hand. In 
the presence of insufficient or overabundant bone, when one modality cannot be considered for 
mainstream treatment, another one can. In cases of overlap, more than one modality is 
appropriate for the available bone presented. Scientifically, the overlapping modalities are equally 
valid, insofar as each can safely and effectively provide additional abutment support for 
restorative dentistry. In such cases, one should apply the clinical criteria for an ideal implant 
system, provided in Chapter 7 , to the modalities under consideration. If two modalities can be 
used safely and effectively, considerations such as time, esthetics, cost, complexity, and trauma 
become important, and can guide the practitioner to make the decision that most benefits the 
patient.
[11]
  
The broader message of this chapter is that the combined scope of treatment using all three 
abutment-providing modalities—the multimodal approach—is far greater than the scope of 
treatment exclusively using any one modality. Collectively, the use of these three modalities 
represents the true scope of treatment possibilities afforded by implant dentistry.
[12]
 Every 
practitioner should understand the indications and contraindications of each modality, and share 
this understanding with patients considering treatment. 
DETERMINING WHETHER IMPLANT TREATMENT CAN SUCCEED  
Determining whether implant treatment can succeed is one of the most important concepts in 
implant dentistry, and is a consideration that must be incorporated into the diagnosis and 
treatment planning routine of every implant dentistry practitioner in every case. If a dental implant 
of any kind is placed successfully into or onto the available bone, heals properly, and is fitted with 
its final prosthesis, will it be able to withstand the anticipated load? Can it do the job asked of it? 
Just because an implant can be placed and heal successfully does not mean that it will be able to 
withstand the forces to which it will be subjected. Not every implant configuration can support an 
equal load long-term in health. The various implant configurations exist to advantageously use 
the various volumes and configurations of available bone one encounters in candidate implant 
dentistry patients. 
If it is deemed likely that an implant considered for use in a case would not remain in health long-
term, the treatment plan should be changed, or the case may fail. This is the same consideration 
applied to evaluate potential natural abutments in conventional prosthodontics, in that sometimes 
a natural tooth available for abutment support may be deemed unable to bear the load in health 
long-term, and therefore is avoided or splinted to other teeth. 
In a way, asking an entry-level practitioner to make this determination is premature. Realistically, 
one cannot accurately determine how much load an implant should be able to withstand until one 
has gained experience observing the course of several mainstream cases. Generally, if one 
follows the guidelines established in Chapter 1 to determine whether a case is mainstream, an 
implant appropriate for the available bone will be able to withstand the anticipated load. Cases 
similar to the teaching cases discussed in the step-by-step procedure chapters should succeed. 
However, in any type of case, including the most predictable of mainstream cases, it is important 
to be sure that one is asking the implants to do a realistic job. The case must not be 
underengineered. This consideration gains in importance as one progresses toward treating 
intermediate and advanced cases, in which the capability of the implants to withstand anticipated 
load cannot be taken for granted. Proper case engineering is essential. In intermediate and 
advanced cases, the judgment of the practitioner has a greater influence on the ultimate outcome 
of the case. 
In addition to evaluating available bone, the practitioner must consider the nature of the patient. Is 
the patient a gentle, weak, or aged person, or a vigorous person and a habitual bruxer? Other 
factors such as the opposing dentition must also be taken into consideration. For example, an 
opposing removable denture affords more shock absorption than natural teeth and therefore will 
impart less force to the implant-supported prosthesis. Proper occlusion is also an important 
consideration 
AVAILABLE BONE AS THE PRIMARY DIAGNOSTIC CONSIDERATION  
Mainstream Cases Use Existing Available Bone  
Mainstream cases use the available bone that exists preoperatively. It is a fundamental precept of 
mainstream implant dentistry that the implant should be selected to fit the anatomy and volume of 
the available bone, and that the available bone should not need to be altered or augmented 
substantially to accommodate a specific implant modality. As discussed in Chapter 15 , bone 
enhancement techniques can change the anatomy of the alveolar ridge, sometimes radically. 
However, such techniques are not considered mainstream because of the complexity of 
treatment, insufficient long-term success and survival data, and lack of general consensus on 
preferred materials and methods of placement for different types of treatment. The prognostic 
value of altering an alveolar ridge to fit a preselected implant modality or configuration is 
questionable. It is certainly easier to select an implant that fits the available bone as presented. 
Abundant long-term success and survival data support such a course of action. Chapter 8 
presents some of these data. 
Range of Available Bone Volume Suitable for Each Implant Modality  
This section analyzes the available bone that is typically required for each of the abutment-
providing modalities, dimension by dimension, and identifies the conditions in which only one 
modality can fit the available bone to provide mainstream treatment. 
Root Forms.  
The ideal available bone parameters for a typical conventional root form configuration are shown 
in Box 16-1 . No available bone presentations exist for which only the root form modality can be 
used to provide mainstream treatment.  
Box 16-1  
IDEAL AVAILABLE BONE PARAMETERS FOR A ROOT FORM WITH 4-MM DIAMETER 
AND 10-MM DEPTH  
 
    Bucco/labio-lingual width: 6 mm 
    Mesio-distal length: 8 mm 
    Depth: 12 mm 
 
Bucco/Labio-Lingual Available Bone Width.  
The width of a root form implant is its diameter. It is best to have 1 mm of crestal bone width at 
the bucco/labiolingual borders of any endosteal implant on the day of insertion. Three-
dimensional finite element analysis in conjunction with clinical observation indicates that this is 
generally the minimum amount of investing bucco/ labio-lingual bone required at the ridge crest to 
absorb functional loads within physiologic limits of health.
[13]
 The reason that the amount of 
required investing bone at the ridge crest is smaller than in other areas is because cortical bone 
offers more support. Clinically, in mainstream cases, this means that a conventional root form 
implant with a diameter of 4 mm requires a pretreatment ridge width of 6 mm as measured 1 to 2 
mm apical to the ridge crest. 
Mesio-Distal Available Bone Length.  
Because a root form is round in cross section, its length is its diameter. If a root form is inserted 
adjacent to a tooth or another root form, a minimum of 2 mm of clearance between them is 
recommended in mainstream cases. This amount of proximal bone is required because the 
mesial and distal of the implant interface is almost entirely against cancellous bone. There is a 
much higher percentage of cortical contact against the buccal/labial and lingual interfaces.
[14]
  
Available Bone Depth.  
Conventional root forms used for mainstream implant dentistry treatment are typically 10 mm 
deep. It is advised to have approximately 2 mm of clearance beyond the apical end of the implant 
to the nearest landmark. Thus, for conventional root forms, 12 mm of available bone depth is 
generally recommended. It is permissible to reduce the height of the ridge crest to create the 
sufficient ridge width provided that in doing so a sufficient depth of available bone remains from 
the reduced crest to the nearest landmark to place the implant with 2 mm of clearance. 
Plate/Blade Forms.  
The ideal available bone parameters for a typical plate/blade form configuration are shown in Box 
16-2 . When evaluating available bone for insertion of a plate/blade form implant, it is useful to 
know that in general, an inverse relationship exists between the implant’s length and depth. A 
longer configuration requires less depth to function within physiologic limits of health long-term, 
whereas a configuration that is shorter mesio-distally requires greater depth.  
Box 16-2  
IDEAL AVAILABLE BONE PARAMETERS FOR A PLATE/BLADE FORM WITH 18-MM 
LENGTH AND 8-MM DEPTH  
 
    Bucco/labio-lingual width: 3.35 mm 
    Mesio-distal length: 22 mm 
    Depth: 10 mm 
 
The plate/blade form is the only modality that can provide mainstream treatment in cases within 
certain ranges of available bone depth and width. 
Bucco/Labio-Lingual Available Bone Width.  
Most plate/blade forms are 1.2 to 1.35 mm in width. Thus, with 1 mm as the minimum required 
width of investing bone buccally and lingually, the minimum ridge width for insertion of a 
plate/blade form in a mainstream case is 3.35 mm as measured 1 to 2 mm below the crest. This 
relatively small width requirement is the primary reason that plate/blade forms have such wide 
diagnostic applicability. 
In cases with sufficient depth of available bone for the insertion of an endosteal implant but width 
less than 6 mm, the plate/blade form modality is indicated. 
Mesio-Distal Available Bone Length.  
A minimum of approximately 2 mm of clearance should exist between the mesial or distal border 
of a plate/blade form and an adjacent tooth root or other implant. 
Available Bone Depth.  
Using any plate/blade form configuration, 2 mm of clearance is ideal between the implant and any 
landmarks beyond its depth. In mainstream cases, ridge crest height rarely needs to be reduced 
to create the sufficient ridge width of 3.35 mm. In cases in which depth of available bone is 6 to 
10 mm, the plate/blade form modality is usually the only modality indicated. 
Subperiosteal Implants.  
The maximum available bone parameters for placement of a subperiosteal implant are shown in 
Box 16-3 . Whereas in endosteal implant dentistry insufficient available bone can contraindicate 
the use of a configuration, in subperiosteal implant dentistry overabundant alveolar bone is a 
contraindicating factor. Therefore, whereas in endosteal implant dentistry minimum available 
bone requirements are considered, in subperiosteal implantology the maximum available bone 
that allows a satisfactory prognosis is considered.  
Box 16-3  
AVAILABLE BONE MAXIMUMS FOR A SUBPERIOSTEAL IMPLANT  
 
    Bucco/labio-lingual width: No limit 
    Mesio-distal length: No limit 
    Depth: 6-8 mm posteriorly, 8-12 mm anteriorly 
 
Subperiosteal implants are the only modality that can offer mainstream treatment when available 
bone depth is insufficient for placement of an endosteal implant. 
Bucco/Labio-Lingual Width.  
In subperiosteal implant dentistry, width is not a limiting factor, although greater width is 
desirable. 
Mesio-Distal Length.  
Length of available bone is not a limiting factor in subperiosteal implant dentistry. In mainstream 
unilateral subperiosteal cases, in which the prosthesis is supported by a combination of implant 
and natural co-abutments, the length of the implant is naturally dictated by the length of the 
edentulous span. When relatively fewer teeth have been lost, the length of the implant is relatively 
short, and total support of the prosthesis is compensated by the fact that more natural tooth co-
abutment support remains. When more teeth have been lost, the implant length, and therefore 
the amount of support offered by the implant, increases with the length of the edentulous span 
onto which the implant is designed, and the number of teeth planned for the overlying prosthesis 
increases. 
Available Bone Depth.  
Excessive depth from the ridge crest to the nearest landmark contraindicates the use of a 
subperiosteal implant. In cases in which there is sufficient residual alveolar ridge to insert 
endosteal implants that can function within physiologic limits of health, endosteal implants should 
be used. 
The maximum acceptable depth of available bone for mainstream treatment using a posterior 
unilateral subperiosteal implant is 6 to 8 mm. In the presence of less than this depth, 
subperiosteal implants are ideal. In fact, in such cases, only the subperiosteal implant modality is 
indicated. This is also true in cases with 6 to 8 mm of available bone depth but less than 3.35 mm 
of width as measured 1 mm below the ridge crest, because this lack of width contraindicates 
insertion of a shallow plate/blade form despite adequate depth. When more than 6 to 8 mm of 
bone depth is available with sufficient ridge width, endosteal implants are better suited for the 
case at hand. Anteriorly, the maximum available depth allowable for mainstream treatment using 
a subperiosteal implant increases by 2 to 4 mm, and sometimes more, depending on the width of 
the ridge crest and other factors. 
Incidence of Appropriate Available Bone for Each Modality  
Having a general idea of the range of anatomic presentations typically encountered in implant 
dentistry candidates is helpful in deciding which modality or modalities to learn first. For 
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