Regenerative periodontal procedures

Question 1

Describe the periodontal ligament (3)

Answer 1

0.15-0.2mm

Sharpey’s fibres with fibroblasts, osteblasts and cementoblasts

Question 2

What is regeneration? (3)

Answer 2

o Goal of periodontal surgery – stop progression
of disease – long junctional epithelium
o More idealistic goal – restore structure and
function of lost periodontal tissues (root
cementum; PDL; AB; CT attachment)
o Regeneration – only in vertical defects

Question 3

Regenerative techniques (4)

Answer 3

o Bone substitutes
o Guided tissue regeneration
o Growth factors and biologicals
o Grafting and combined therapies

Question 4

Bone substitutes and their use (7)

Answer 4

• Bone forming cells – Osteogenesis
• Serve as scaffold – Osteoconduction
• Contains bone inducing substances –osteoinduction
 Bone Autogenous
o Bone Allografts
o Bone xenograft (Bio-Oss)
o Bone Alloplastic materials
hydroxyapatitie Bioactive glasses

Question 5

Bio-Oss (3)

Answer 5

1. Clot stabilization facilitated by Bio-Oss® interconnecting macro and micropores
2. Revascularization, migration of osteoblasts (purple) and in-growth of woven bone (yellow) is enhanced by Bio-Oss® scaffolding
3. Lamellar bone and Bio-Oss® are successfully integrated after approximately six months. Bio-Oss® is included in the natural physiologic
   remodeling process (osteoclasts - Blue)

Question 6

Bioglass technology (4)

Answer 6

Under a microscope, a Bioglass® particle
would look very much like a piece of smooth
sand. The size of these particles is about
that of a grain of ordinary table salt.
Upon introduction of Bioglass® into a defect site, an immediate chemical reaction starts with the body
fluids which modifies the surface of the Bioglass®
making it more attractive to organic molecules.
The modified surface of the Bioglass particles immediately begins to attract the body’s own “building blocks” for tissue
regeneration – Proteins – which are already
present in body fluids.
In a continuing chemical reaction occurring over the next few days, a “framework” of hydroxyl-carbonate-apatite crystals forms on the surface of the Bioglass® particles which traps and bonds these “building blocks” to create a virtual “nursery” for new tissue growth.

Question 7

Guided tissue regeneration (3)

Answer 7

o Is used for the prevention of epithelial migration
along the cemental wall of the pocket and
maintaining space for clot stabilisation
o GTR – placing a membrane barrier to cover the bone and PDL thus temporarily separating them
from the gingival epithelium and CT
o This prevents epithelial migration and favours
repopulation of area by cells from PL and bone

Question 8

How does GTR work? (4)

Answer 8

o Epithelial tissues develop
faster than connective
tissues
o Membrane forms a barrier
which prevents the down
growth of the epithelium
o Connective tissue then has
a chance to develop further
into the defect
o Most biodegradable
membranes e.g. BioGuide

Question 9

Enamel matrix derivative (2)

Answer 9

Amelogenin production
and biological action
Detail of the period when the root sheath
cells (blue) secrete enamel matrix proteins. Following formation of the
protein matrix on the surface of the mineralizing dentine, cementoblasts
(Red) start producing cementum (Light blue) which anchors collagen fibers.

Question 10

Sequence of biological action after application of EmdogainGel during surgery (4)

Answer 10

1. Attraction
2. Attachment and proliferation
3. Differentiation
4. Alveolar bone

Question 11

Predictability EmdogainGel treatment (Heden et al 1999) (4)

Answer 11

o 87 % of sites > 2 mm attachment gain
o Majority of sites > 4 mm att.gain
o Average bone fill 69 %
o “Emdogain technique is a predictable
way to enhance periodontal regeneration
outcome”.