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Glass Ionomer Cement (GIC) - Composition, Properties, Composition and Modifications

- Glass Ionomer Cement is also known as Polyalkenoate cement / Man-made dentin / Dentin Substitute / Aluminosilicate Polyacrylic cement (ASPA)
COMPOSITION :
Powder / Liquid Contents
Powder / Ion Leachable Glass
  • Silica           -          35 - 50 %
  • Alumina      -           20 - 30 %
  • NaF             -           3 - 6 %
  • AlF3            -           1.5 - 2.5 %
  • Aluminium Phosphate  -    4 - 12 %
  • Traces of Barium, Strontium for radioopacity
Liquid
  • Polyacrylic acid        -        45 %
  • Itaconic acid + Maleic Acid + Tricarballylic acid    - 5 % (Decreases Viscosity)
  • Tartaric acid (Increases working time)
  • Water   - 50 %
CLASSIFICATION:
Type I GIC - Luting cement
Type II GIC - Restorative Cement
Type III GIC - Liner
Type IV GIC - Fissure Sealant
Type V GIC - Orthodontic Cement
Type VI GIC - Core Build Up Cement
Type VIII and Type IX - Posterior packable GIC for atraumatic restorations
Among the first three types, the highest cumulative release of fluoride after 30 days is from glass ionomer liner.
- GIC was introduced as a potential replacement for silicate cement. It has been evolved as a hybrid from the silicate and polycarboxylate cement.
Light Polymerization:
The powder contains initiators for light curing and liquid component is modified with hydroxyethyl methacrylate (HEMA).
The polymerization starts when exposed to light and subsequently followed by acid base reactions. This is called dual cure GIC.
PROPERTIES:
GIC has low fracture toughness and wear resistance.
It is very sensitive to moisture, especially during initial setting reaction. During this period, absorption of water leads to weak cement and over drying will lead to cracks in the cement. Therefore, the surface of cement should be protected by coating with varnish or cocoa butter during setting. 
It bonds chemically to the tooth structure.
- The bond of enamel is always higher than that of dentin.
- It is relatively biocompatible, the pulpal reaction is greater than ZOE but less than Zinc Phosphate Cement.
- Due to continuous fluoride release, it has some anticariogenic property.
 
- Powder: Liquid ratio is 3:1 by weight. Mixing should be done by agate or plastic spatula.
- 10 % polyacrylic acid should be used for conditioning the cavity surface before insertion of the cement.
- Final finishing is done 24 hours after the insertion.
MODIFICATIONS OF GIC:
a) Miracle Mix or Silver Cement
Silver-Tin alloy powder is added to GIC Powder. None of the properties were improved and it gave a gray or blackish color to the cement. It is also called as silver alloy mix.
b) Glass Cermet or Cermet
Glass and metal ( Silver-tin-titanium) powders were sintered at high temperature and made to react with liquid. It improved the fracture toughness and wear resistance and at the same time maintained the esthetics.
c) Resin modified GIC
BisGMA, TEGDMA, are added to powder and HEMA to the liquid. With exposure of light polymerization is initiated along the methacrylate groups. After that the liquid reacts with the glass particles through acid base reaction. It improved the wear resistance and decreased the sensitivity to
water attack. 
d) Compomer (Polyacid modified composite resins)
It is a combination of composite and GIC. Glass particles are partially silanated (for bonding with the matrix) and are added as fillers in the composite resin. There is no water in the reaction. The properties were inferior to composites but superior to resin modified GIC.
e) Bilayered or Sandwich restoration
In this technique, GIC is used as a liner under composite restorations. It increases the retention form as GIC bonds both the tooth and composite and the fluoride content reduces secondary caries.
f) Tunneling restorations
Joining the occlusal lesion with the proximal lesion by means of a prepared tunnel under the involved marginal ridge. The marginal ridge remains intact. GIC is used as the restorative material in this technique.
g) Atraumatic restoration (ART)
Involves removal of affected tooth structure with hand instruments, followed up by restoring with GIC material (GC Fuji VIII).
h) High viscosity GIC
Used for atraumatic restorative treatment. They contain small particle sizes and a high P/L ratio, yielding greater compressive strength and excellent packability. Also used for core buildups, primary tooth fillings and intermediate restoration.
i) Calcium aluminate GIC
It is a hybrid product of calcium aluminate and  GIC. The GIC components are responsible for early properties (i.e. setting time, viscosity, and strength). The calcium aluminate contributes to basic pH, biocompatibility and reduction in microleakage. Also called as hydraulic cement.

Diagnosis of Hairy Leukoplakia

Hairy Leukoplakia is the second most common HIV-associated oral mucosal lesions after Candidiasis. It is non malignant and is not pathognomic for HIV since other immunodeficiencies such as cancer chemotherapy are also associated with hairy leukoplakia. The common site for this condition is on the lateral borders of tongue in form of vertical white folds.


Diagnosis of Hairy Leukoplakia Features
Provisional Diagnosis Characteristic gross appearance with or without non responsiveness to antifungal therapy
Presumptive Diagnosis Light microscopy of histologic sections revealing hyperkeratosis, koilocytosis, acanthosis, and absence of inflammatory cell infiltrate
OR
Light microscopy of cytologic operations demonstrating nuclear beading and chromatin margination
Definitive Diagnosis Insitu Hybridisation of histologic or cytologic specimen revealing positive staining for EBV DNA
OR
Electron microscopy of histologic or cytologic specimen showing herpes-like particles
OR
Epstein-Barr Virus was demonstrated with polymerase chain reaction technique.

Multiple Endocrine Neoplasia (MEN) Syndrome - Types

Multiple Endocrine Neoplasia (MEN) Syndrome
MEN - I
  • Hyperplasia of  pituitary gland with acromegaly
  • Hyperplasia of parathyroid and adrenal cortex
  • Hyperplasia of pancreatic islets with increased production of gastrin, insulin, and glucagon with peptic ulcers and gastric hypersecretion
MEN - II (Sipple's Syndrome)
  • Hyperplasia of parathyroid gland
  • No tumors of pancreas. No peptic ulcer.
  • Patients may have pheochromocytomas of the adrenal medulla and medullary carcinoma of the thyroid gland
MEN - III
  • Pheochromocytomas and Medullary carcinoma of the thyroid gland
  • Oral neuromas that are common on lips, tongue and buccal mucosa.
  • The lips are described as Bumpy lips.


Multiple Endocrine Neoplasia or MEN Syndrome are classified  into following types :
A. MEN - I
  • Hyperplasia of  pituitary gland with acromegaly
  • Hyperplasia of parathyroid and adrenal cortex
  • Hyperplasia of pancreatic islets with increased production of gastrin, insulin, and glucagon with peptic ulcers and gastric hypersecretion
B. MEN - II
  • Hyperplasia of parathyroid gland
  • No tumors of pancreas. No peptic ulcer.
  • Patients may have pheochromocytomas of the adrenal medulla and medullary carcinoma of the thyroid gland
C. MEN - III
  • Pheochromocytomas and Medullary carcinoma of the thyroid gland
  • Oral neuromas that are common on lips, tongue and buccal mucosa.
  • The lips are described as Bumpy lips.

MCQs on Pulp and Periapical Infections - Oral Pathology


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# All of the following statements about the typical features of a periapical granuloma are TRUE except :
A. It consists of proliferating granulation tissue
B. It can form only if the periapical bone is resorbed
C. It shows evidence of local antibody production
D. It results from immunologically mediated tissue damage

# Phlegmon is a :
A. Sexually transmitted disease
B. Type of cellulitis
C. Type of osteomyelitis
D. Endocrine Disease

# Most common cyst in oral region is :
A. Medial cyst
B. Radicular cyst
C. Follicular cyst
D. Nasolabial cyst

# Dental cyst:
A. Occurs from reduced enamel epithelium
B. replaces the tooth to which it is attached
C. is frequently seen with a missing tooth on the X ray
D. Cystic lining of stratified squamous epithelium

# The earliest response of pulpitis is :
A. Cyst formation
B. Calcification
C. Hyalinization
D. Formation of dental granuloma

# Garre's chronic non supurative sclerosing osteomylitis is characteried clinically by:
A. Endosteal bone formation
B. Periosteal bone formation
C. Resorption of medullary bone
D. Resorption of cortical bone

# Abscess formation is particularly characteristic of infections with which of the following microorganisms ?
A. Viruses
B. Rickettsiae
C. Streptococci
D. Staphylococci

# Organism involved in cellulitis is :
A. Streptococcus mutans
B. Streptococcus pyogenes
C. Pneumococci
D. Klebsiella

# An acute apical abscess is usually a result of :
A. Periodontal pocket
B. Occlusal interference
C. Necrotic pulp
D. Chronic gingivitis

# Which of the following periapical conditions is associated with a vital pulp ?
A. Apical cyst
B. Apical scar
C. Condensing osteitis
D. Chronic apical periodontitis

# The main causative agent of Ludwig's angina is:
A. Anaerobic Streptococci
B. Aerobic Streptococci
C. Staphylococci
D. Legionella infection

# The most common organism involved in a periapical abscess is :
A. Streptococcus pyogenes
B. Streptococcus viridans
C. B hemolytic Streptococci
D. Non hemolytic Streptococci

# The earliest radiographic sign of osteomyelitis is :
A. Solitary or multiple radiolucent areas
B. Increased granular radioopacity
C. Blurring of trabecular outlines
D. Formation of sequestrum appearing as radioopaque patches

# Osteomyelitis begins as an inflammation of :
A. Cortical bone
B. Periosteum
C. Medullary bone
D. Periosteum and inner cortex

# Focal sclerosing osteonyelitis is:
A. Due to excessive periosteal bone formation
B. An extremely painful condition
C. Due to low grade chronic infection
D. A common sequel following sequestrectomy

# A tooth with a 3 month history of pain, which was worse when hot liquid were in mouth. After extraction, the tooth was split open. The pulp chamber was completely filled with pus. A few remnants of pulp tissue were found in the apical end. The condition is :
A. Acute partial Pulpitis
B. Acute total pulpitis
C. Suppurative pulpitis
D. Strangulation of pulp

# Chronic hyperplastic pulpitis is:
A. necrotizing
B. Suppurative lesion
C. proliferation of a chronically inflammed pulp
D. also called as phoenix abscess

# Periapical cyst is usually preceded by:
A. Periapical granuloma
B. Periodontal abscess
C. Periapical abscess
D. All of the above

# Acute osteomyelitis is most frequently caused by which of the following microorganisms ?
A. Gonococcus
B. Enterococcus
C. Streptococcus
D. Staphylococcus
# An asymptomatic tooth has deep caries on occlusal surface. Radiograph shows radiopaque mass at apex of the tooth; this mass is most likely to be :
A. Cementoma
B. Condensing osteitis
C. Chronic apical periodontitis
D. Acute apical periodontitis

# A person experiences throbbing pain at night. It is due to:
A. Acute pulpal degeneration
B. Acute periodontal abscess
C. Chronic pulpitis
D. Cellulitis

# Pain due to acute irreversible pulpitis is :
A. Spontaneous
B. Sharp-shock like
C. Lasting for short time
D. Continuous

# Reversible pulpitis change to irreversible pulpitis primarily because of :
A. Vascular strangulation
B. Reduced host resistance
C. Invasion of microorganisms
D. An increase in microbial virulence

# Which is not true of Ludwig's angina?
A. Usually arises from an infected molar
B. Involves submandibular space
C. May need emergency tracheostomy
D. None of the above

# Odontogenic epithelium responsible for the formation of dental cyst is :
A. Cell rests of Serres
B. Enamel Organ
C. Reduced enamel epithelium
D. Cell rests of Malassez

# The caries of enamel surface leads to accentuation of:
A. Incremental lines of Retzius
B. Perikymata
C. Imbrication lines of Pickerill
D. Wickham's Striae

# Constant feature associated with radicular cyst is :
A. an impacted tooth
B. a missing tooth
C. a non vital tooth
D. an anomalous tooth

# Which of the following differentiates between condensing osteitis and benign cementoblastoma ?
A. Condensing osteitis is associated with vital tooth whereas cementoblastoma is associated with a non vital tooth
B. In condensing osteitis, radiopacity is attached to tooth whereas in cementoblastoma it is not
C. Cementoblastoma is associated with vital tooth whereas condensing osteitis is associated with non vital tooth
D. In cementoblastoma, radiopacity is attached to the tooth whereas in condensing osteitis it is not

# Best way to differentiate periapical cyst and periapical granuloma is:
A. Radiographically
B. Histologically
C. Clinically
D. None of the above

# A diffuse spreading inflammatory lesion is due to bacterial enzyme:
A. Coagulase
B. Hyaluronidase
C. Peroxidase
D. Bradykinin

# Chronic periostitis in children is known as:
A. Cherubism
B. Garre's osteomyelitis
C. Histiocytosis X
D. Tuberculous osteomyelitis

# Which of the following is more prone to osteomyelitis?
A. Maxilla
B. Zygoma
C. Palatine bone
D. Mandible

# The chronic osteomyelitis of jaw consists of :
A. Condensing osteitis
B. Sclerotic cemental mass
C. Chronic diffuse sclerosing osteomyelitis
D. All of the above

# The fascial spaces involved in the Ludwig's Angina are:
A. Unilateral - Submandibular and Sublingual spaces
B. Bilateral - Submandibular and Sublingual Spaces
C. Unilateral - Submandibular, Sublingual and Submental spaces
D. Bilateral - Submandibular, Sublingual and Submental Spaces
# Three stages in progression of acute odontogenic infection are :
A. Periapical osteitis, cellulitis, abscess
B. Abscess, cellulitis, periapical osteitis
C. Cellulitis, abscess, periapical osteitis
D. Periapical osteitis, abscess, cellulitis

# The tooth most commonly involved in chronic focal sclerosing osteomyelitis is:
A. Maxillary second molar
B. Maxillary third molar
C. Maxillary first molar
D. Mandibular first molar

# Cyst arising from Rests of Malassez is:
A. Dental Cyst
B. Dentigerous cyst
C. Radicular cyst
D. Keratocyst

# Low grade infection which leads to localized periosteal reaction is:
A. Garre's Osteomyelitis
B. Acute Osteomyelitis
C. Condensing Osteitis
D. Local alveolar Osteitis

# Tiny linear or arc-shaped bodies, amporphous, brittle and eosinophilic in reaction, found in association with some odontogenic cysts, are called:
A. Civatte bodies
B. Russel Bodies
C. Guarneri Bodies
D. Rushton bodies

# The cells most frequently found in a granuloma are:
A. Mast cells
B. Giant cells
C. Lymphocytes
D. Neutrophils

# Most used selective medium for Streptococcus mutans is :
A. Mac conkey agar
B. Mitius salivarius bacitracin agar
C. Nutrient agar
D. Tellurite medium

# Most demineralized zone in enamel caries is :
A. Translucent zone
B. Body of lesion
C. Dark zone
D. Surface zone

# The gelatinous deposit adherent on the tooth surface is called as:
A. Materia alba
B. Plaque
C. Calculus
D. All of the above

# Streptococcus mutans produces an adhesive polymer from sucrose, known as:
A. Levans
B. Lectins
C. Glucans
D. Polyfructans

# Liquefaction foci of Miller is a hostopathological observation in:
A. Cemental caries
B. Early enamel caries
C. Advanced enamel caries
D. Advanced dentinal caries

# Which of the following is cariostatic?
A. Selenium
B. Magnesium
C. Cadmium
D. Molybdenum
# Progression of dental caries on pit and fissures occur from:
A. Apex of the pit and fissure
B. Wide end of the pit and fissure
C. Lateral surface of the pit and fissure
D. Bottom of the pit and fissure

# Which of the following represents a soluble polysaccharide found in dental plaque and is formed from the fructose moiety of the sucrose?
A. Levan
B. Dextran
C. Amylopectin
D. Hyaluronic acid

# Plaque microflora can split carbohydrates. What does it mean?
A. Saccharolytic
B. Saprophytic
C. Virulent
D. Avirulent

# True about caries, all except:
A. Infectious and transmissible
B. Not due to microorganisms
C. Can develop in the absence of sucrose
D. Microorganisms play the most essential role

# A 30 year old patient with radiograohic appearance of endosteal bone formation, sclerosed bone is likely to be suffered from?
A. Garre's osteomyelitis
B. Chronic focal sclerosing osteomyelitis
C. Acute osteomyelitis
D. Chronic Osteomyelitis