02.08.23 Hoda_IJOMI

Question 1

How is Alzheimer’s assoc. with perio pathogens?

Answer 1

Beyloun ‘20 - retrospective from NHANES data.
Alzheimer’s disease had perio pathogens in the brain tissue

Ide ‘16 - cohort study, n=60. Periodontitis is assoc. with periodontitis

Poole ‘13 - 10 brains from Alzheimer’s pts. Staining for T.f. , T.d. and P.g antibodies. Found that LPS from perio bacteria can access the brain

Tang ‘22 - mouse model. P.g. and T.d. (red complex bacteria) shows that perio infection of t.d. had increased bone loss, inflammation. T.d. can colonize the brain and cause signs of Alzheimer’s disease

Dominy ‘19 Cadavers & mice - Gingipains are increased in AD brains when periodontitis is present. Detecting p.g. DNA in the brain is possibly a predictor of Alzheimer’s disease

Question 2

Describe the IDRA tool for peri-implant disease risk

Answer 2

Heitz-Mayfield & Lang ‘15
Claus Lang was the first to think of it
“Spider tree” - 8 arms

1. Prosthesis - Cleansable, poor fit (supramucosal), poor fit submuc/ excess cement, not cleanable
2. Perio susceptibility - 1A, 2A/B, 3A/B, 3C/4, 4C
3. RM (to bone) - STL, ≥0.5, ≤0.5
4. SPT - Compliant, ≤5 mo, 6 mo, casual, no
5. BL/Age - 0.5 (start point for yellow zone), 0.75, 1.0 (start red zone) , 1.25, 1.5
6. PD ≥5mm - 2 (starting point for yellow zone), 4, 6 (starting point for red zone), 8, 10
7. BOP % - 9 (starting point for yellow zone), 16, 25 (starting point for red zone), 36, 49 %
8. History of Perio - yes/no

Question 3

Who discussed risk factors / risk indicators of periodontitis?

Answer 3

Genco ‘13
“He was the one behind the NHANES study” - says Dr Wang
Risk factors: Diabetes, smoking
Risk indicators: Alcohol, stress, RA, obesity, osteoporosis

Dr Wang says - it didn’t include vitamin D deficiency

Question 4

What is the Location of posterior superior alveolar artery in the sinus?

Answer 4

Güncü ‘11
121 CT scans (242 sinuses) from patients undergoing sinus augmentation procedure and/or implant therapy

Prevalence of sinus septa was 16.1%, prevalence of sinus pathology (membrane thickening, chronic sinusitis, cysts) was 24.8%

Artery was seen in 64.5% of all sinuses and mostly intraosseous (68.2%), 26% below the Schneiderian membrane, and 5.7% on the outer cortex of the sinus wall.

PSAA has a mean distance from the alveolar crest of 18 mm. It is located intraosseous in 68%.

Question 5

What is Leqembi?

Answer 5

Leqembi (“Lecanemab”) is a novel monoclonal antibody directed against aggregated soluble (“protofibril”) and insoluble forms of amyloid beta (Aβ)

2 hallmark findings to diagnose AD are the extracellular deposits of :
* β-amyloid peptide (Aβ-plaques)
* Flame-shaped micro-fibrillary tangles of the microtubule binding protein tau

Complication: Amyloid related imaging abnormalities (ARIAs) in 3% of pts. MRI shows brain edema

Lipitor reduces cholesterol by only 30%. But in the medical field, it is the “number 1 drug” (says Dr. Wang)

Question 6

What study from Michigan looked at the prosthetic-biologic connection and peri-implant health?

Answer 6

Saleh IJOMI
* Buccolingual positioning: at least 2 mm bone should be buccal to the implant.
* Vertical position: Too shallow = overcontoured crown. Too deep = deeper pockets and more perio pathogens. Place implants >3mm below CEJ (but not too deep)
* M-D position: may affect crown contour & cleansability
* Diameter: A too narrow implant creates overcontoured crown = obtuse emergence angle. Same if a narrow implant is placed too shallow.
* Abutment height: Effect depends on tissue thickness. Thick tissue + thin abutment: increased bone remodeling. Thin tissue + short abutment: more esthetic, but Increased bone remodeling. Thinn tissue + tall abutment = Can place slightly subcrestally to reduce risk of thread exposure

Note: Dr. Wang “never uses” 2.8 (Zimmer TSV = same as Straumann standard) implant - uses 1.8 mm (same as Straumann standard plus) because prosth will add a 1mm collar, then will build the prosthesis. And the ST is ~3mm thick.

“Bone will never attach to the Zimmer MTX surface”

Question 7

What Michigan study examined implantoplasty in regenerated vs non-regenerated defects?

Answer 7

Lin IJOMI
Systematic Review & Meta-analysis
Regeneration group: 97% survival
Non-Regen group: 94% survival

Regen group had better bone gain (3.08mm vs. 0.5mm in non-regen group) = about 6X more bone gain in the regen group.

Question 8

What is the Michigan study describing flap advancement techniques in a pig cadaver model?

Answer 8

Steigmann IJOMI
Aim: to test the efficacy of six surgical approaches for flap advancement in an ex vivo porcine model
1. Vertical release
2. Periosteal scoring
3. Mucosal detachment (MDT)
4. MDT + horizontal incision
5. MDT + vertical incision
6. MDT horizontal, vertical, and cutback incision

Measurements
* Group 6 has the max flap advancement (but not by a huge amount- doesn’t make much difference)
* Flap tensile strength: Group 1>6>5>4>3>2
* Exposed mucosa surface: Group 6>5>4>3>2>1
* The linear regression model showed the flap advancement increased by 0.62 mm for every 10 mm2 increase in the exposed mucosal surface (the slope).

Dr. Wang says: “each periosteal scoring adds 1-2 mm”

Question 9

What study looked at shortened treatment time for maxillary lateral sinus grafting with simultaneous implant placement?

Answer 9

Valentini IJOMI
Retrospective 10 yr study
The mean residual bone height was 2.6 ± 0.6 mm.
The healing time before loading was 4.18 ± 0.63 months.

In a first evaluation in 2014 the early implant survival rate (EIsR) was 96.8% after a mean period of 5.4 ± 2.2 years.

A second evaluation in 2019 after a mean period of 10.4 ± 2.2 years showed a late implant survival rate (LIsR) of 83.1%.

The failures after 2014 were all caused by peri-implantitis, which affected 14.6% and 16.8% of patients and implants, respectively.

Dr. Wang: “1/5 of all sinus grafts will fail due to large particles and only using grafted bone (with no safety zone of ~5mm autogenous bone)”. If using allograft, Dr Wang uses 4:1 ratio of large particle (cortical) :small particle (cancellous). Small particle size 250-850, large particle 1-2 mm. Small particle goes on outside (?)

Question 10

What study described how a severely resorbed subantral ridge decreases long-term implant survival with sinus floor augmentatioN?

Answer 10

Niu IJOMI
Retrospective = 104 sinus surgeries where RBH < 6.5mm
INCELL implant system.

Aim: To identify the impact of residual bone height on 5-year implant survival and prosthetic complication rates in patients who underwent maxillary sinus grafting.
Implants placed 6-8 mo after the grafting.

A residual bone height < 3 mm did not impact the survival rates of implants placed in grafted maxillary sinuses or the prosthetic complication rate after 5 years of functional loading.

This is a bad study due to sample sizes being small and unequal among groups, arbitrarily chosen healing time and confusing methodology.

Question 11

Describe the study on resonance frequency analysis comparing different drilling techniques on implant stability

Answer 11

Sunny IJOMI
RCT double-blinded
Compared:
* Conventional drill technique (sequentially enlarging osteotomy drills)
* Simplified drill technique (starting drill, then final drill)
* Modified conventional drill technique (final drill is counterclockwise (osseodensification)

Findings: ISQ is best in the Modified Conventional Drill. Conventional is the same as simplified drill

Dr. Wang says: Irrigation in drilling only matters if drill is >15mm long, or if doing osseodensification. If osseodensifying, you have to first remove the cortical bone with regular drill movement & then do the osseodensification.
Implant removal: 3.7 - 4.1 diameters, use the same one. If 4.7 or 5 or bigger, use a bigger one. (Not sure what “one” is… removal kit device?) Need the inner thread at 45Ncm. Otherwise, if the inner thread is fractured, then trephine