Prostho Sheet 15

Question 1

What is the main pieces of implant

Answer 1

1-implant
2-abutment
3-crown

Question 2

What is the difference between cover screw and gingival former

Answer 2

-covers screw put at the same level of surface of the implant
-Ginger former put higher all the way into the Gingiva that do shaping to the emergance profile or transition phase between bone and Crown

Question 3

What we called secondary stability in implant

Answer 3

Osteointegration

Question 4

What is the primary stability in implant

Answer 4

Primary stability is mechanical stability.
Mechanical stability is features or the micro surface of the implant in relation with bone when we
put the implant at the beginning.

Question 5

Describe what happened to primary and secondary stability with time

Answer 5

With time the mechanical stability decreased because we have
bone remodeling or biological process is happening. So, as the process starts the biological
stability “osteointegration” increases.

Question 6

Give the name of secondary stability

Answer 6

-osteointegration
-biological stability

Question 7

If we choose conventional implant when we can put the implant

Answer 7

immediate
implant is discovered to take the benefit of mechanical stability at the beginning. So, we have
two choices either put implant and crown in the same time or conventionally wait 3 months and
put the crown

Question 8

What the secondary stability depends on

Answer 8

The secondary stability of a dental implant largely depends on the degree of
new bone formation at the bone-to-implant interface.

Question 9

What does BIC referred to

Answer 9

At the end of the
remodeling phase, about 60% to 70% of the implant surface is in contact
with bone. This is termed bone-to-implant contact (BIC) and is widely used
in research to measure the degree of osseointegration.

Question 10

How much should the BIC be to say that the implant is successful

Answer 10

60-70%

Question 11

What things used to determine the stability of the implant

Answer 11

1-insertion torque
2-resonance frequency analysis
3-percussion test
4-reverse tourque test

Question 12

Define the insertion torque of the implant

Answer 12

It is the rotational force recorded during the surgical
insertion of a dental implant into the prepared site, and
it is expressed in Newton centimeters.

Question 13

What is resonance frequency analysis and how it works

Answer 13

It essentially applies a bending load, which mimics the
clinical load and direction and provides information about
the stiffness of the implant–bone junction.
• Implant Stability Quotient (ISQ) is a measurement (based
on a scale from 1–100) of the lateral stability of the dental implant, which
serves as a surrogate for the degree of stability achieved.
The score must be 70 or more which means this implant when I put to it lateral load,
the implant not move that means the implant has osteointegration.

Question 14

How percussion test work to measure the stability of the implant

Answer 14

Not commonly used. It’s a subjective method but we can use it and we will hear a dull
sound when we do percussion.

Question 15

How reverse torque test work to measure the stability of the implant

Answer 15

Not commonly used
We use a wrench in the reverse direction to assess how much force it takes to rotate the implant
But It does not make sense. Because When we put 60 N/cm torque, and we
remove it by 30 N which means there is no osteointegration.

Question 16

Mention the three type of implants

Answer 16

1-Endosteal / Endosseus implant within the bone itself, the type that we use today.
• One cortex.
• 2 types: blade and root-form.
2-Subperiosteal: above the bone and below the mucosa.
3-Transosteal: we call them Bi cortical which means the implant starts from one cortex and ends
to another cortex.

Question 17

What is the difference between blade implants and root form implants

Answer 17

Blade implant :-In cases of very narrow ridge.
it’s very wide mesiodistally

Root-form implant:-Cylinder or Screw-shaped.
what we use today

Question 18

What are the type of root form implants

Answer 18

1-cylinder implant
2-screw -shaped implant

Question 19

What is the difference between bone level and tissue level in screw shaped implant

Answer 19

-tissue level implant :- when the top of the implant is at the same level of the mucous or if it deeper by 0.5 mm
The core of the implant should be smooth because it contact with tissue and bacteria
Usually used for posterior implant because its less aesthetic
Less hygienic
-bone level implants:- when the top of the implantis at the same level as the crest of the bone
More hygienic and aesthetic

Question 20

What is the difference between one piece vs two piece implant

Answer 20

two piece implant: the abutment is different part than implant.
one piece: the abutment is attached with implant. Used in very narrow implant or temporary implant or in ortho
we use tads that inserted to the bone to act as anchorage unit.

Question 21

What is the material used for implant

Answer 21

Mainly titanium alloy used in implant.
lately zirconia alloy we used especially in anterior
area.
gold alloy is expensive and mineable “not strong
enough”.
also stainless steel and Co-Cr alloys was used.

Question 22

What is the difference between parallel sided and tapered screw shaped implant

Answer 22

The tapered screw design was developed to provide two
advantages over the parallel-sided implant: increased initial
stability and anatomic conformity “avoid touching anatomical structure”.

Question 23

What is the advantage of adding threads to the implant

Answer 23

-Better initial stability in bone.
− Transfer forces to the supporting bone.
− Thread shape can affect the type of the force that is
transmitted at the interface (compressive, shear or
tensile).
** The main aim is transmit the forces from tensile strength to
compressive strength.
**When I put an occlusal load to implant that does not have threads, the
implant will gets up and down the bone the alveolar bone (shear stress).
**Threads will produce compressive stress that stabilize the implant in place.

Question 24

What shape of thread we have for the implant and which one is the most commonly used

Answer 24

We have many shapes of thread of the implant:
square, buttress, reverse buttress.
Today the most common use is buttress and
reverse buttress.

Question 25

How does the depth of the thread of the implant affect the 1-compressive force 2- primary stability

Answer 25

1-The deeper the thread, the larger the surface area available for compressive force transfer to the supporting bone. • 2-Increasing thread depth also increases the insertion torque and primary stability in low-density bone because it increases initial bone-implant contact. The wider the threads, the more stability have, especially in softer bone.

Question 26

If we have dense bone what thread depth we prefer (high/low) and why

Answer 26

In denser bone the increased insertion torque of implants with greater thread depth may require the use of a bone tap to fully seat the implant Here we have 2 symmetrical implants same length, diameter the one of them have 0.1mm in depth of thread and other have 0.3mm in depth of thread. In softer bone preferably we will use 0.3mm. in harder bone preferably we use 0.1mm because the crest of the thread have low fracture resistance if we use wider depth the possibility of fracture will be higher.

Question 27

What is the effect of the implant diameter on1-occlusal forces resistant 2-stress at the bone implant interface

Answer 27

1-A larger diameter implant is better able to resist occlusal forces, particularly in the molar region. 2-Wider implants decrease stress at the bone-implant interface. Conversely, smaller-diameter implants show increased stress at this interface. • Stress is force divided by the cross-sectional area the force is acting on For implants of a given length and geometry, wider implants have more surface area to occlusal forces to act on and thus lower stress. • Besides decreased stress at the bone-implant interface, wider implants are generally more resistant to fracture from occlusal overload and fatigue conditions.

Question 28

What affects the surface area of the implant more the length or the diameter

Answer 28

when we increase from 10mm to 16mm the difference between the surface area increased only 70mm. but when we have the same length and different diameter from 3.5mm to 5mm we have the duoble surface area have. So, whenever you can try to place the widest implant, but this doesn’t mean if we need to replace lateral we put 5.0mm, so the crown becomes much smaller in size than implant. Greater implant length is beneficial in decreasing stress and strain in the supporting bone; however, a larger implant diameter is more effective.

Question 29

What is the implant collar What does it design determine

Answer 29

1-The implant collar serves as the transition area between the prosthesis and the body of the implant. The surface of the collar is typically smoother than the threaded region of the implant body, and the diameter of the collar region is larger than the body of the implant below it. 2-Its design dictates the placement of the prosthetic interface relative to the bone and gingival tissue surrounding the implant site, as well as stress distribution into the surrounding cortical bone.

Question 30

What is the difference between bone level and tissue level collar in implant

Answer 30

Bone level: the collar is small. Tissue level collar is larger, the same height to tissue. • The concept of collar is: when I put the abutment there is nothing fit 100%. We will have small space that helps bacteria to enter and cause some sort of inflammation. In tissue level the micro gap or collar will be higher and the inflammation will be in the tissues that can help the patient to clean and eliminate it. In bone level, the micro gap will be lower and the inflammation will be difficult to clean that result bone loss. So, for this reason we increase using tissue level.

Question 31

What are benefits of the microthreads at the collar of the implant

Answer 31

Microthreads enhance stress distribution around the implant neck. So, less bone loss especially in the Crestal area.

Question 32

Why the tip of the implant is tapered

Answer 32

to allow some of the axial length of the implant to enter the implant site before the threads come into contact with the walls of the osteotomy.

Question 33

What are the two shapes of the tip of the implant

Answer 33

We have two shapes of tip either sharp or round. Implants at upper posterior we use round tip “to protect entering to sinus”.

Question 34

What is the benefit of the grooves at the apical region of the implant

Answer 34

• Antirotating and stabilizing insertion. The groove will fill with bone so when I do anti rotation to implant I will feel of resistant and more stability. • Tapping of the implant threads into the wall of the osteotomy. • Grooves that work as “step back” to increase the primary stability and when we drill in the bone to insert the implant these grooves will give move area to drill so we have more primary stability and more surface area.

Question 35

Why we need the surface of the implant to be rough

Answer 35

To increase the friction

Question 36

What are the commonly used scientific parameter to describe the surface roughness

Answer 36

1) Ra (profile roughness average) (2D). Most studies talked about it 2) Sa (area roughness average) (3D).

Question 37

What are the classification of surface roughness of the implant?

Answer 37

•smooth surfaces have an Ra value of less than 0.5 μm. Mainly at collar only. • minimally rough surfaces have an Ra of 0.5 to 1.0 μm. • moderately rough surfaces have an Ra of 1 to 2 μm. • rough surfaces have am Ra of greater than 2 μm. I don’t love it because if I have an exposure, it will accumulate also of bone. We commonly use minimally and moderately rough. Most implants are moderately rough. In case we have exposure and bone loss, it will be easier to do smoothening to reduce the accumulation of plaque and bacteria.

Question 38

How to make the implant rough

Answer 38

1-additive -Titanium plasma spray(cause bone loss we don’t use anymore) -hydroxyapatite coating -oxidation 2-subtractive -Blasting -acid etching -Blasting and etching 3-new surface modification -Surface energy -Laser etching -bioactive proteins

Question 39

‏ what is the implant platform and what are thier type?

Answer 39

Platform is where the implant connect to abutment There are external and internal platform Also, there is a platform matching and platform switch Matching known as butt joint it is more close to the bone so we have more bone loss Switch where the abutment is Narrower than the implant at the connection it is far from the bones so less bone loss

Question 40

What is the favorite implant in case of 1-shape 2-diameter 3-length 4-collar 5-platform 6-threads 7-apical region

Answer 40

Shape: tapered. Especially If I have minimal space tapered is better than parallel. I can use parallel also but tapered is better. • Diameter: wide. • Length: shorter possible I can. • Collar: machined rather than roughened surface at the upper region of the implant collar, with microthreads in cortical region. I can use smooth “machined” without microthreads, but I will have bone loss especially if the diameter is narrow. So, we compensate for the absence of microthreads by wide diameter. • Platform switch vs. match • Threads: square or buttress, pitch 0.8-1.6 mm, depth more than 0.4 mm. square helps us with type of forces, but now it has more complications so, we use buttress and reverse buttress more. • Apical region: tapered, rounded, has grooves. •

Question 41

What instrument used in implant surgery to 1-incise tissue 2-reflect tissue 3-grasp tissue 4-remove bone 5-remove soft tissue

Answer 41

1-scalpel and surgical blades (usually 15c) 2-molt periosteal elevator 3-adson forceps 4-rongeur and bone file 5-curette

Question 42

Describe the classification of bone density D1-D2-D3-D4 and what is the best for implant

Answer 42

D1: very dense bone. We can put implant here but avoid putting excessive pressure on bone that produces heat generation. D2: thick cortex “good stability” with enough dingy bone “good blood supply”. D3: thin cortex with more spongy bone “very good blood supply”. D4: soft bone “spongy bone is dominant. we can put implant here bout with wider diameter. **the best density is D1 -D2

Question 43

Mention the bone density for In general o Anterior mandible is usually …. o Posterior mandible is ….. o Anterior maxilla is …..bone. o Posterior maxilla is often ……bone.

Answer 43

In general o Anterior mandible is usually D2. o Posterior mandible is D3. o Anterior maxilla is D3 bone. o Posterior maxilla is often D4 bone.

Question 44

When anterior mandible is resorbed it becomes ….., when posterior maxilla is sinus-grafted it becomes …..

Answer 44

When anterior mandible is resorbed it becomes D1, when posterior maxilla is sinus-grafted it becomes D3.

Question 45

Bone density may be most precisely determined before surgery by a ………………of the edentulous site (accompanied by…………..It’s not 100% accurate but at least it gives me an idea. The whiter area the denser it is. A common point at which to evaluate bone quality is ……….. The density of bone is determined by the ………,,,,,and evaluation continues until the final osteotomy preparation.

Answer 45

Bone density may be most precisely determined before surgery by a computed tomography (CT) scan of the edentulous site (accompanied by Hounsfield values of the bone). It’s not 100% accurate but at least it gives me an idea. The whiter area the denser it is. A common point at which to evaluate bone quality is during surgery. The density of bone is determined by the initial bone drill, and evaluation continues until the final osteotomy preparation.

Question 46

What are the drilling sequence for the implant

Answer 46

1-step 1-:pilot drill 2-step 2:- position verification 3-step 3:-second twist drill 4-step 4:-final shaping drills 5-step 5:-crest module and bone tap drills 6-implant insertion 7-take x-ray and place gingival former or cover screw

Question 47

Step1: PILOT DRILL the first drill that enters the bone which is very thin and very sharp. It gives me an indication……… • …………starter drill. • Diameter :…….mm. • Depth: ……..mm.

Answer 47

Step1: PILOT DRILL the first drill that enters the bone which is very thin and very sharp. It gives me an indication where I will put the implant. • End-cutting starter drill. • Diameter :1.5 – 2.0 mm. • Depth: 7-9 mm.

Question 48

Step2: Position verification • Direction indicator (depth gauge), which corresponds to the initial bur diameter, is then inserted into the osteotomy and the angulation and position assessed. It gives me if the implant will be parallel to the adjacent tooth or not. If it is not, we can modify it because ………... • A ………… radiograph should be obtained to determine ……:..::::...

Answer 48

Step2: Position verification • Direction indicator (depth gauge), which corresponds to the initial bur diameter, is then inserted into the osteotomy and the angulation and position assessed. It gives me if the implant will be parallel to the adjacent tooth or not. If it is not, we can modify it because the diameter of this bur is narrow. • A periapical radiograph should be obtained to determine proximity to any vital structures.

Question 49

Step3: Second twist drill • ……… drill. • Diameter: ……... • Inserted to ……..depth. • A slight correction of position or angulation with a ……….. drill may be completed.

Answer 49

Step3: Second twist drill • End-cutting twist drill. • Diameter: 2.5 mm. • Inserted to the required depth. • A slight correction of position or angulation with a Lindemann drill may be completed.

Question 50

Step4: Final shaping drills (we start drilling bone.) • Shaping drills are used to sequentially widen the osteotomy to the matching diameter of the implant being placed. • Usually, the final drill will be within ….mm of the final diameter of the implant diameter (i.e., a 4.0-mm implant will have a final drill size of approximately 3.2 mm). ▪ We have 3 burs according to the size of the implant. For ex if the implant size is 3.5mm we should use bur smaller than 3.5mm. ▪ The reason for using smaller bur is ……….. ▪ If the bone is soft, ……… ▪ If the bone is dense, …….

Answer 50

Step4: Final shaping drills we start drilling bone. • Shaping drills are used to sequentially widen the osteotomy to the matching diameter of the implant being placed. • Usually, the final drill will be within 1.0 mm of the final diameter of the implant diameter (i.e., a 4.0-mm implant will have a final drill size of approximately 3.2 mm). ▪ We have 3 burs according to the size of the implant. For ex if the implant size is 3.5mm we should use bur smaller than 3.5mm. ▪ The reason for using smaller bur is when we put the implant, it will make some condensation to the bone that give more stability. ▪ If the bone is soft, we skip the final bur to give more condensation and stability. ▪ If the bone is dense, we use crest module “tap drills”.

Question 51

Step5: Crest Module and Bone Tap Drills • Most implant crest modules (implant neck) are larger in diameter than the implant body. • Used in ……. to ……: • Do not use it in …….bone. • A copious amount of irrigation should be used. • Used in ……. to prepare …….. When we insert the implant, it will insert without needing to cut some bone to have space to their threads. Because we use thread former that create space to implant’s threads. Because if the implant inserted in hard bone without thread former used if will increase the incidence of breakage to threads. • Used at 30 RPM or less. • We cut the cortex to remove the resistance that we will have when we insert the implant.

Answer 51

Step5: Crest Module and Bone Tap Drills • Most implant crest modules (implant neck) are larger in diameter than the implant body. • Used in hard bone to prepare the crestal aspect of the implant osteotomy. • Do not use it in D3, D4 bone. • A copious amount of irrigation should be used. • Used in hard bone to prepare the threads before implant insertion. (thread former). When we insert the implant, it will insert without needing to cut some bone to have space to their threads. Because we use thread former that create space to implant’s threads. Because if the implant inserted in hard bone without thread former used if will increase the incidence of breakage to threads. • Used at 30 RPM or less. • We cut the cortex to remove the resistance that we will have when we insert the implant.

Question 52

Step6: Implant insertion • The implant may be inserted with a …… or …….. • The advantage of inserting an implant with a handpiece is that ………, and ………, especially in poorer quality of bone (e.g., D3 and D4 bone). • If the implant is tightened into the osteotomy and significant stress occurs at the crestal area, …….. may occur and an increase in the ……….. will occur. If this should occur, the implant may be ………... • When we insert the implant, we use …… RPM with torque that give me an indication how much is it stable in their area.

Answer 52

Step6: Implant insertion • The implant may be inserted with a hand ratchet or handpiece. • The advantage of inserting an implant with a handpiece is that the placement will be more ideal, and deviation is less likely, especially in poorer quality of bone (e.g., D3 and D4 bone). • If the implant is tightened into the osteotomy and significant stress occurs at the crestal area, pressure necrosis may occur and an increase in the devitalized zone of bone around the implant during healing will occur. If this should occur, the implant may be unthreaded 1 to 2 mm and then reinserted back into the osteotomy. • When we insert the implant, we use very low RPM (round per minute)with torque that give me an indication how much is it stable in their area.

Question 53

Difference between gingival former and cover screw placement

Answer 53

1-cover screw :-we put the cover screw and close the flap. Then after 3 months we open flap and put the healing abutment and keep it open until healing finished. 2-gingival former :-at the time of insertion, we put gingival former “healing abutment” and keep it exposed until healing happens.

Question 54

Dental Implant Surgical Protocol in dense bone (D1 Bone)

Answer 54

• In D1 bone, all the drills of the surgical system should be utilized, so less heat is generated. • In D1 bone, the final bone preparation may be sized slightly larger in both width and height. • A bone tap should be used in D1 bone before insertion of a threaded implant, Because the final drill osteotomy is almost 1 mm smaller than the outer diameter of the implant, the bone tap creates the space for the thread of the implant. • Use of copious amount of irrigation. • Use of new sharp drill. • Use of large crest module. • Here we use all drills.

Question 55

Dental Implant Surgical Protocol in soft bone (D3 or D4)

Answer 55

• In soft bone, the final drill is not used because the placement of the implant allows for the lateral displacement of the bone, increasing bone density. • A crest module or bone tap drills should not be used. • With any drill in D3 bone, it should only be passed once in the osteotomy to avoid oversizing the preparation.