NEET MDS Synopsis
Carisolv
Conservative DentistryCarisolvCarisolv is a dental caries removal system that offers a unique approach to
the treatment of carious dentin. It differs from traditional methods, such as
Caridex, by utilizing amino acids and a lower concentration of sodium
hypochlorite. Below is an overview of its components, mechanism of action,
application process, and advantages.
1. Components of Carisolv
A. Red Gel (Solution A)
Composition:
Amino Acids: Contains 0.1 M of three amino acids:
I-Glutamic Acid
I-Leucine
I-Lysine
Sodium Hydroxide (NaOH): Used to adjust pH.
Sodium Hypochlorite (NaOCl): Present at a lower
concentration compared to Caridex.
Erythrosine: A dye that provides color to the gel,
aiding in visualization during application.
Purified Water: Used as a solvent.
B. Clear Liquid (Solution B)
Composition:
Sodium Hypochlorite (NaOCl): Contains 0.5% NaOCl
w/v, which contributes to the antimicrobial properties of the solution.
C. Storage and Preparation
Temperature: The two separate gels are stored at 48°C
before use and are allowed to return to room temperature prior to
application.
2. Mechanism of Action
Softening Carious Dentin: Carisolv is designed to
soften carious dentin by chemically disrupting denatured collagen within the
affected tissue.
Collagen Disruption: The amino acids in the formulation
play a crucial role in breaking down the collagen matrix, making it easier
to remove the softened carious dentin.
Scraping Away: After the dentin is softened, it is
removed using specially designed hand instruments, allowing for precise and
effective caries removal.
3. pH and Application Time
Resultant pH: The pH of Carisolv is approximately 11,
which is alkaline and conducive to the softening process.
Application Time: The recommended application time for
Carisolv is between 30 to 60 seconds, allowing for quick
treatment of carious lesions.
4. Advantages
Minimally Invasive: Carisolv offers a minimally
invasive approach to caries removal, preserving healthy tooth structure
while effectively treating carious dentin.
Reduced Need for Rotary Instruments: The chemical
action of Carisolv reduces the reliance on traditional rotary instruments,
which can be beneficial for patients with anxiety or those requiring a
gentler approach.
Visualization: The presence of erythrosine allows for
better visualization of the treated area, helping clinicians ensure complete
removal of carious tissue.
CASTING DEFECTS
Dental Materials
CASTING DEFECTS
Classification :
1) Distortion.
2) Surface roughness .
3) Porosity .
4)Incomplete casting .
5) Oxidation .
6) Sulfur contamination .
Distortion
It is usually due to the distortion of wax pattern.
To avoid this :
Manipulation of the wax at its softening temp
Invest the pattern at the earliest .
If storage is necessary store it in a refrigerator .
Surface roughness
May be due to :
Air bubbles on the wax pattern .
Cracks due to rapid heating of the investment .
High W/P ratio .
Prolonged heating of the mold cavity .
Overheating of the gold alloy .
Too high or too low casting pressure .
Composition of the investment .
Foreign body inclusion.
POROSITY
May be internal or external .
External porosity causes discolouration .
Internal porosity weakens the restoration .
Classification of porosity .
I .Those caused by solidification shrinkage :
a) Localised shrinkage porosity .
b) Suck back porosity .
c) Microporosity .
They are usually irregular in shape .
II ) Those caused by gas :
a) Pin hole porosity .
b) Gas inclusions .
c) Subsurface porosity .
Usually they are spherical in shape .
III ) Those caused by air trapped in the mold :
Back pressure porosity .
Localised shrinkage porosity
Large irregular voids found near sprue casting junction.
Occurs when cooling sequence is incorrect .
If the sprue solidifies before the rest of the casting , no more molten metal is supplied from the sprue which can cause voids or pits (shrink pot porosity )
This can be avoided by -
- using asprue of correct thickness .
- Attach the sprue to the thickest portion of the pattern .
-Flaring of the sprue at the point of atttachment .
-Placing a reservoir close to the pattern .
Suck back porosity
It is an external void seen in the inside of a crown opposite the sprue .
Hot spot is created which freezes last .
It is avoided by :
Reducing the temp difference between the mold & molten alloy .
Microporosity :
Fine irregular voids within the casting .
Occurs when casting freezes rapidly .
Also when mold or casting temp is too low .
Pin hole porosity :
Upon solidification the dissolved gases are expelled from the metal causing tiny voids .
Pt & Pd absorb Hydrogen .
Cu & Ag absorb oxygen .
Gas inclusion porosities
Larger than pin hole porosities .
May be due to dissolved gases or due to gases Carried in or trapped by molten metal .
Apoorly adjusted blow torech can also occlude gases .
Back pressure porosity
This is caused by inadequate venting of the mold .The sprue pattern length should be adjusted so that there is not more than ¼” thickness of the investmentbetween the bottom of the casting .
This can be prevented by :
- using adequate casting force .
-use investment of adequate porosity .
-place the pattern not more than 6-8 mm away from tne end of the casting .
Casting with gas blow holes
This is due to any wax residue in the mold .
To eliminate this the burnout should be done with the sprue hol facing downwards for the wax pattern to run down.
Incomplete casting
This is due to :
- insufficient alloy .
-Alloy not able to enter thin parts of the mold .
-When the mold is not heated to the casting temp .
-Premature solidification of the alloy .
-sprues blocked with foreign bodies .
-Back pressure of gases .
-low casting pressure .
-Alloy not sufficiently molten .
Too bright & shiny casting with short & rounded margins :
occurs when wax is eliminated completely ,it combines with oxygen or air to form carbon monoxide .
Small casting :
occurs when proper expansion is not obtained & due to the shrinkage of the impression .
Contamination of the casting
1) Due to overheating there is oxidation of metal .
2) Use of oxidising zone of the flame .
3) Failure to use a flux .
4) Due to formation sulfur compounds .
Black casting
It is due to :
1) Overheating of the investment .
2) Incomplete elimination of the wax .
Erythema Multiforme
PeriodontologyErythema Multiforme
Characteristics: Erythema multiforme presents with
"target" or "bull's eye" lesions, often associated with:
Etiologic Factors:
Herpes simplex infection.
Mycoplasma infection.
Drug reactions (e.g., sulfonamides, penicillins, phenylbutazone,
phenytoin).
Garre’s Osteomyelitis
Oral Pathology
Garre’s Osteomyelitis (Chronic Osteomyelitis with Proliferative Perosteitis)
Chronic Non Suppurative Sclerosing Osteitis/ Periostitis Ossificans.
Non suppurative productive disease characterized by a hard swelling.
Occurs due to low grade infection and irritation
The infectious agent localizes in or beneath the periosteal covering of the cortex & spreads only slightly into the interior of the bone.
Occurs primarily in young persons who possess great osteogenic activity of the periosteum.
Clinical Features
Uncommonly encountered, described in tibia and in the head and neck region, in the mandible.
Typically involves the posterior mandible & is usually unilateral.
Patients present with an asymptomatic bony, hard swelling with normal appearing overlying skin and mucosa.
On occasion slight tenderness may be noted
pain is most constant feature
The increase in the mass of bone may be due to mild toxic stimulation of periosteal osteoblasts by attenuated infection.
Radiographic features
Laminations vary from 1 – 12 in number, radiolucent separations often are present between new bone and original cortex. (“onion skin appearance”)
Trabeculae parallel to laminations may also be present.
Histologic Features
Reactive new bone.
Parallel rows of highly cellular & reactive woven bone in which the individual trabeculae are oriented perpendicular to surface.
Osteoblasts predominate in this area.
D/D for Garre’s Osteomyelitis
Ewing's sarcoma
Caffey’s disease
Fibrous dysplasia
Osteosarcoma
Treatment
Removal of the offending cause.
Once inflammation resolves, layers of the bone consolidate in 6 – 12 months, as the overlying muscle helps to remodel.
If no focus of infection evident, biopsy recommended.
The Parietal Bones
Anatomy->The two parietal bones (L. paries, wall) form large parts of the walls of the calvaria.
->On the outside of these smooth convex bones, there are slight elevations near the centre called parietal eminences.
->The middle of the lateral surfaces of the parietal bones is crossed by two curved lines, the superior and inferior temporal lines.
->The superior temporal line indicates an attachment of the temporal fascia; the inferior temporal line marks the superior limit of the temporalis muscle.
->The parietal bones articulate with each other in the median plane at the sagittal suture. The medial plane of the body passes through the sagittal suture.
->The inverted V-shaped suture between the parietal bones and the occipital bones is called the lambdoid suture because of its resemblance to the letter lambda in the Greek alphabet.
->The point where the parietal and occipital bones join is a useful reference point called the lambda. It can be felt as a depression in some people.
->In addition to articulation with each other and the frontal and occipital bones, the parietal bones articulate with the temporal bones and the greater wings of the sphenoid bone.
->In foetal and infant skulls, the bones of the calvaria are separated by dense connective tissue membranes at sutures.
->The large fibrous area where several sutures meet are called fonticuli or fontanelles.
->The softness of these bones and looseness of their connections at these sutures enable the calvaria to undergo changes of shape during birth called molding. Within a day or so after birth, the shape of the infant’s calvaria returns to normal.
->The loose construction of the new-born calvaria also allows the skull to enlarge and undergo remodelling during infancy and childhood.
->Relationships between the various bones are constantly changing during the active growth period.
->The increase in the size of the cranium is greatest during the first 2 years, the period of most rapid postnatal growth of the brain.
->The cranium normally increases in capacity until about 15 or 16 years of age; thereafter the cranium usually increases only slightly in size as its bones thicken for 3 to 4 years.
Agranulocytosis
General Pathology
Agranulocytosis. Severe neutropenia with symptoms of infective lesions.
Drugs. are an important cause and the effect may be due to .
-Direct toxic effect.
-Hypersensitivity.
Some of the 'high risk drugs are.
-Amidopyrine.
-Antithyroid drugs.
-Chlorpromazine, mapazine.
-Antimetabolites and other drugs causing pancytopenia.
Bloodpicture: Neutropenia with toxic granules in neutrophils. Marrow shows decrease in granulocyte precursors with toxic granules in them.
Beta-Adrenergic blocking Agents- Antianginal Drugs
Pharmacology
Beta-Adrenergic blocking Agents
• Prototype - Propranolol
• Prevent or inhibit sympathetic stimulation
– Reduces heart rate
– Myocardial contractility
– Reduce BP - decreases myocardial workload and O2 demand
• In long-term management used to decrease frequency and severity of anginal attacks
• Added when nitrates do not prevent anginal episodes
• Prevents exercise induced tachycardia
• Onset of action 30 min after oral dose. 1-2 min IV
Therapeutic Actions
• Block Beta adrenergic receptors in the heart and juxtaglomerular apparatus
• Decrease the influence of the sympathetic nervous system decreasing excitability of the heart
• Decrease cardiac output.
• Indicated for long term management of anginal pectoris caused by atherosclerosis
Atenolol, metoprolol, and nadolol have the same actions, uses, and adverse effects as propranolol, but they have long half-lives and can be given once daily. They are excreted by the kidneys, and dosage must be reduced in clients with renal impairment.
COMPOSITE RESINS -Bonding Agents
Dental Materials
Bonding Agents
Applications-composites, resin-modified gIass ionomers, ceramic bonded to enamel restorations, veneers, orthodontic brackets, and desensitizing dentin by covering exposed tubules (Maryland bridges, composite and ceramic repair systems, amalgams and amalgam repair, and pinned amalgams)
Definitions;-
Smear layer - Layer of compacted debris on enamel and/or dentin from the cavity preparation process that is weakly held to the surface (6 to 7 MPa) , and that limits bonding agent strength if not removed
Etching (or, conditioning)- smear layer removal and production of microspaces for micromechanical bonding by dissolving –minor amounts of surface hydroxyapatite crystals
Priming..- micromechanical (and chemical) bonding to the microspaces created by conditioning step.
Conditioning/priming agent-agent that accomplishes both actions
Bonding- formation of resin layer that connect the primed surface to the overlying restoration (e.g., composite) .. –
Enamel bonding System-for bonding to enamel (although dentin bonding may be a Second step)
Dentin bonding system for bonding to dentin (although enamel bonding may have been a first step)
• First-generation dentin bonding system for bonding to smear layer
• New-generation dentin bonding system- for removing smear layer and etching intertubular dentin to allow primer and/or bonding agent to diffuse into spaces between collagen and form hybrid zone
Enamel and dentin bonding system-for bonding to enamel and dentin surfaces with the same procedures
Amalgam bonding system for bonding to enamel, dentin, and amalgam, dentin and amalgam during an amalgam placement procedure or for amalgam repair
Universal bonding system-for bonding to enamel, dentin, amalgam, porcelain , or any other substrate intraorally that may be necessary for a restorative procedure using the same set of procedures and materials
Types
Enamel bonding systems
Dentin bonding systems
Amalgam bonding systems
Universal bonding systems
Structure
o Components of bonding systems
o Conditioning agent-mineral or organic acid
Enamel only 37% phosphoric acid
Dentin only or enamel and .dentin---37% phosphoric acid, citric acid, maleic acid, or nitric acid
o Priming agent
Hydrophobic-solvent-soluble, light cured monomer system
Hydrophilic-water-soluble, light-cured monomer system
Bonding agent
BIS-GMA-type monomer system
UDMA-type monomer system
Reaction
Bonding occurs primarily by intimate micromechanical retention with the relief created by the conditioning step
Chemical bonding is possible but is not recognized as contributing significantly to the overall bond strength
Manipulation-follow manufacturer's directions
Properties
Physical-thermal expansion and contraction may create fatigue stresses that debond the interface and permit micro leakage
Chemical-water absorption into the bonding agent may chemically alter the bonding
Mechanical-mechanical stresses may produce fatigue that debonds the interface and permits microleakage
Enamel bonding-adhesion occurs by macrotags (between enamel prisms) and microtags (into enamel prisms) to produce micromechanical retention
Dentin bonding-adhesion occurs by penetration of smear layer and formation of microtags into intertubular dentin to produce a hybrid zone (interpenetration zone or diffusion zone) that microscopically intertwines collagen bundles and bonding agent polymer
Biologic
Conditioning agents may be locally irritating if they come into contact with soft tissue
Priming agents (uncured), particularly those based on HEMA, may be skin sensitizers after several contacts with dental personnel
Protect skin on hands and face from inadvertent contact with unset materials and/ or their vapors
HEMA and other priming monomers may penetrate through rubber gloves in relatively short times (60 to 90 seconds)