3. CONTENTS
• Definitions
• Classification of host modulating agents
• Introduction to SDD
• MMPs
• Mechanism of action of SDD
• Indications
• Contraindications
• Side effects
• Prescription with periodontal treatment
• Combination
• Conclusion
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4. WHAT IS “HOST” ?
• Host can be defined as “the organism from
which a parasite obtains its nourishment.”
OR
• In the transplantation of tissue “The
individual who receives the graft.”
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5. WHAT IS “MODULATION”?
• Modulation is defined as “the alteration of
function or status of something in response to
a stimulus or an altered chemical or physical
environment.”
( Taber’s medical dictionary, 2004 )
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6. HOST MODULATORY THERAPY (HMT)
• Host modulatory therapy (HMT) is a treatment
concept that aims to reduce tissue destruction
and stabilize or even regenerate the
periodontium by modifying or downregulating
destructive aspects of the host response and
upregulating protective or regenerative
responses.
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7. CLASSFICATION OF HOST
MODULATING AGENTS
• A variety of different drug classes have been evaluated as
Host Modulation agents:
Systemically administered Agents :
1. NSAIDs
2. Bisphosphonates
3. SDD (Sub-antimicrobial-Dose Doxycycline)
Locally administered Agents :
1. Topical NSAIDs
2. Enamel Matrix Proteins
3. Growth factors
4. BMP ( Bone Morphogenetic Proteins )
5. Tetracyclines
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8. INTRODUCTION TO SDD
• Only systemically administered HMT ( host modulatory therapy )
• 20mg dose of doxycycline ( periostat ), taken twice daily for 3
months ( maximum of 9 months )
• Approved by FDA ( US food & drug administration )
• Accepted by ADA
• Indicated as an adjunct to SRP ( Scaling & root
planning ) in the treatment of chronic periodontitis
• Exerts therapeutic effect by enzyme cytokine & osteoclast
inhibition ( no antibiotic effect )
• Recently modified release – SDD is approved by FDA, which is
used for common skin disorders.
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9. SUB-ANTIMICROBIAL-DOSE
DOXYCYCLINE (SDD)
• It should not be used as a stand-alone
therapy / monotherapy
• Previously known as “low-dose doxycycline”,
in which doxycycline is a member of
tetracycline family of compounds.
• The goal of tetracycline therapy is to
enhance reattachment or even to stimulate
new attachment of the supporting apparatus
& osseous formation.
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10. MMPs
• Before we understand the mechanism of action of SDD,
it is important to know something about MMPs.
• MMPs : Matrix Metalloproteinases
• MMPs are zinc-dependent enzymes, secreted by the
major dell types in the periodontal tissues ( fibroblasts,
kerationocytes, macrophages, PMNs, endothelial cells )
• Capable of degrading extracellular matrix molecules,
including collagen
• Release of excessive quantities of MMPs in inflamed
periodontal tissues, resulting in breakdown of the
connective tissue matrix.
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11. • Predominant MMPs, especially MNP-8, MMP-9
are derive from PMNs & are extremely effective
in degrading type-I collagen, which is the most
abundant collagen type in gingiva & periodontal
ligament.
• Levels of PMN-type MMPs have been shown to
increase with severity of periodontal disease &
decrease after therapy.
• Conclusion is the release of large quantities of
MMPs in the periodontium leads to significant
anatomic disruption & breakdown of the
connective tissue, contributing to the clinical
signs of periodontitis.
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13. • Basically it downregulates the activity of
MMPs, by a variety of
Synergistic mechanisms, including reduction
in cytokine levels & stimulates osteoblastic
activity & new bone formation by
upregulating colllagen production.
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14. INDICATIONS
• In the management of Chronic Periodontitis and
Aggressive Periodontitis.
• SDD can be used in patients with aggressive periodontitis
who are being treated nonsurgically.
• Emerging studies have supported efficacy of SDD as an
adjunct to periodontal surgery (Gapski et al 2004).
• SDD may also be of benefit in cases that are refractory to
treatment, as well as in patients with risk factors such as
smoking or diabetes, in whom the treatment response might
be limited.
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15. CONTRAINDICATIONS
• Any patient with a history of allergy or hypersensitivity to
tetracyclines.
• It should not be given to pregnant or lactating women.
• Children less than 12 years old - because potential for
discoloration of the developing dentition
• Doxycycline may reduce the efficacy of OCPs, and therefore
alternative forms of birth control should be discussed.
• There is a risk if increased sensitivity to sunlight (manifested
by an exaggerated sunburn) seen with higher doses of
doxycycline, although this has not been reported in the
clinical trials using sub-antimicrobial dose.
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16. SIDE EFFECTS
• 20mg dose of doxycycline is usually well tolerated by
the body.
Doxycycline at antibiotic doses (≥100mg) is
associated with adverse effects,
• Photosensitivity
• Hyper-sensitivity reactions
• Nausea
• Vomiting
• Oesophageal irritation
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17. PRESCRIPTION WITH PERIODONTAL
TREATMENT
• SDD is indicated as an adjunct to mechanical periodontal
therapy and should not be used as a standalone therapy.
• SDD should be prescribed to co-incide with the first episode
of SRP and is prescribed for 3 months, up to a maximum of 9
months of continuous dosing.
• Modification of any risk factors such as smoking, nutrition,
stress, contributing medications, faulty restorations, poor oral
hygiene and poor diabetic control, can also be addressed at
this time.
• After initial periodontal treatment, the patient is enrolled
into an intensive periodontal maintenance program.
• At maintenance appointments, the need for further
prescription of SDD can be assessed.
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18. COMBINATIONS
• Combining with Periodontal Surgery
SDD was used as an adjunct to access flap surgery in 24 patients
revealed better probing depth reductions in surgically treated sites
greater than 6 mm compared with surgically treated sites in
patients given placebo.
• Combining with Local Delivery Systems
Preliminary results from a 6-month, 180-patient clinical trial
designed to evaluate the safety and efficacy of SDD combined with
a locally applied antimicrobial and SRP versus SRP alone
demonstrated that patients receiving the combination of
treatments experienced more than a 2-mm improvement in mean
attachment gains and probing depth reductions compared with
SRP alone.
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19. CONCLUSION
• The use of HMTs such as SDD offers the opportunity to
improve the treatment outcomes that can be anticipated
following SRP alone.
• HMT’s are an emerging treatment concept in the
management of periodontitis.
• In the future a range of HMTs targeting different aspects of
the destructive cascade of breakdown events in the PD tissues
are likely to be developed as adjunctive treatments for
periodontitis.
• The goal is to maximize the treatment response by reducing
inflammation and inhibiting destructive processes in the
tissues, which will result in enhanced periodontal stability
after conventional periodontal treatments such as SRP.
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