P: Diagnosis Flashcards
1
Q
What are the indications and contraindications for accelerated tooth movement?
A
Indications include orthodontic treatment requiring faster results.Contraindications may involve certain medical conditions or patient-specific factors that could complicate treatment.
2
Q
What non-surgical interventions are available for accelerated tooth movement?
A
Methods may include the use of specific orthodontic appliances.Techniques like micro-osteoperforation can also be utilized to enhance tooth movement.
3
Q
What surgical interventions can be used for accelerated tooth movement?
A
Procedures may involve corticotomy or piezocision to facilitate faster movement.These interventions aim to reduce the time required for orthodontic treatment.
4
Q
What should be included in an exam night review for accelerated tooth movement?
A
Key concepts of both surgical and non-surgical interventions.Understanding indications, contraindications, and patient management strategies.
5
Q
What are the benefits of accelerated tooth movement in orthodontics?
A
Shortens treatment time, leading to decreased overall treatment costs.Minimizes risks of iatrogenic issues such as root resorption and white spot lesions.
6
Q
What are the indications for using accelerated tooth movement?
A
Used in comprehensive cases where treatment duration is long.Facilitates mechanically challenging orthodontic movements and corrects moderate to severe skeletal malocclusions.
7
Q
What are the contraindications for non-surgical accelerated tooth movement?
A
Avoid in patients with poor periodontal health or prolonged corticosteroid use.Not suitable for patients allergic to specific medications like cytokines or active vitamin D.
8
Q
What types of non-surgical interventions are used for accelerated tooth movement?
A
Modification of biomechanics through customized brackets and archwires.Biological methods including injections of cell mediators and device-assisted methods like low-level laser therapy.
9
Q
What surgical techniques are employed for accelerated tooth movement?
A
Osteotomy or corticotomy procedures.Micro-osteoperforations and piezocision techniques.
10
Q
What biological methods are used to accelerate tooth movement?
A
Injection of active vitamin D3 around the tooth socket.Research primarily conducted on animals, focusing on enhancing bone formation.
11
Q
What are the effects of systemic administration of PGE1 on tooth movement?
A
It is more efficient in accelerating tooth movement compared to other methods.No side effects or pathological damage were observed in the study by Spielmann et al. (1989).
12
Q
How does the combination of PGE2 and calcium ions affect root resorption and tooth movement?
A
This combination reduces root resorption and the speed of tooth movement.However, it still results in an acceleration compared to the control group, as noted by Seifi et al. (2003).
13
Q
What is the role of Parathyroid hormone (PTH) in tooth movement?
A
PTH increases bone resorption by stimulating osteoclasts in response to low serum calcium.Continuous administration can shorten treatment time, but risks undesired resorption in other bones.
14
Q
What are the potential risks associated with the use of PTH for accelerating tooth movement?
A
Long-term risks include undesired resorption in bones like vertebrae.This makes the application of PTH for tooth movement acceleration impractical.
15
Q
What is the function of relaxin in orthodontic treatment?
A
Relaxin is involved in the remodeling of soft tissues and enhances fiber and bone remodeling at tension sites.It may accelerate tooth movement, but studies show mixed results regarding its effectiveness.
16
Q
What did Liu et al. (2005) find about the effects of human relaxin on tooth movement?
A
They found that human relaxin may accelerate tooth movement in early stages in rats.However, a clinical trial indicated that weekly relaxin injections did not affect tooth movement speed.
17
Q
What is the role of the β-2 adrenergic receptor (Adrb2) in bone remodeling?
A
Adrb2 regulates bone formation and is involved in cardiac function and bone remodeling.Studies have shown its involvement in the response to force application in bone tissue.
18
Q
What are the benefits of using self-ligation brackets in orthodontic treatment?
A
Claimed to reduce treatment time by an average of 4 months compared to conventional brackets.Decreases the mean number of visits from 16 to 12 per patient.
19
Q
What does research say about the efficiency of self-ligating brackets compared to conventional brackets?
A
No significant difference in treatment duration during initial alignment of upper or lower arch.Studies show no difference in time or efficiency for en-masse space closure and canine retraction.
20
Q
How does clear aligner therapy compare to traditional orthodontic methods in terms of treatment duration?
A
Invisalign treatment averages 1.4 years, while Tip-Edge treatment averages 1.7 years.Invisalign may result in shorter treatment duration but with poorer outcomes than Tip-Edge treatments.
21
Q
What is the impact of robotic wire-bending on orthodontic treatment time?
A
The median treatment time for SureSmile patients is 15 months, which is 8 months shorter than conventional methods.Conventional patient pool averages 23 months for treatment.
22
Q
What are some physical methods used to accelerate tooth movement in orthodontics?
A
Magnetic fields can influence bone resorption and deposition, potentially accelerating tooth movement.Pulsed electromagnetic fields (PEF) have been shown to accelerate tooth movement in research studies.
23
Q
What are the mechanisms that can accelerate tooth movement in orthodontics?
A
Regional Acceleratory Phenomenon (RAP) enhances bone remodeling through local inflammatory mediators.Increased osteoclastic activity on the compression side and osteoblastic activity on the tension side during tooth movement.
24
Q
What is distraction osteogenesis and how does it affect tooth movement?
A
Distraction osteogenesis involves sectioning bone and using a screw device to move segments apart.This technique can accelerate tooth movement by up to 1.2 mm per week without adverse effects like ankylosis or root resorption.
25
What is the 'surgery first' approach in orthodontics?
This technique involves performing orthognathic surgery before comprehensive orthodontics.It is believed to accelerate tooth movement due to the effects of Regional Acceleratory Phenomenon (RAP).
26
What are corticotomies and their role in accelerating tooth movement?
Corticotomy involves raising a mucoperiosteal flap and performing inter-radicular osteotomies.It is effective in accelerating tooth movement and can also be used to move ankylosed teeth.
27
What is Wilckodontics and how does it differ from traditional corticotomy?
Wilckodontics, or Accelerated Osteogenic Orthodontics (AOO), adds bone allograft over decorticated regions.This modification aims to enhance canine retraction and assist in orthodontic expansion and molar intrusion.
28
What are the proposed advantages of Accelerated Osteogenic Orthodontics (AOO)?
AOO is claimed to provide quicker canine retraction in challenging cases.It may prevent mandibular dehiscence after decompensation in Class 3 cases and enhance post-orthodontic stability.
29
What are the key steps involved in the acceleration of tooth movement during orthodontic treatment?
Incision is made 2 mm short of the gingival papilla and 1 mm above the mucogingival junction.The blade is tapped to a depth of approximately 8 mm at a 45-60 degree angle.Teeth mobility is tested by attempting to move them slightly.Orthodontic forces are applied immediately after the incision.
30
What findings were reported regarding self-ligating brackets compared to conventional brackets?
Randomized clinical trials show no difference in time or efficiency between self-ligating and conventional brackets.Some studies indicate that self-ligating treatment may take longer during the initial alignment phase.
31
What does research say about the effectiveness of AcceleDent Aura appliance in orthodontic treatment?
RCTs found that AcceleDent Aura had no significant effect on crowding relief or pain reduction during alignment.It also did not affect the rate of maxillary premolar extraction space closure.
32
What is the most effective procedure to accelerate tooth movement according to systematic reviews?
Corticotomy is identified as the most effective procedure for accelerating tooth movement.This method enhances the overall efficiency of orthodontic treatment.
33
How do micro-osteoperforations affect the retraction duration of maxillary incisors?
Using piezopunctures can decrease the retraction duration of maxillary incisors by three weeks.This suggests a significant impact on treatment timelines when using this technique.
34
What is the effect of MOPs on en-masse retraction rates during orthodontic treatment?
MOPs increased the en-masse retraction rate by 0.31 mm/month in the first month.This effect is minimal compared to the total duration of orthodontic treatment.
35
What is the current state of research on non-surgical interventions to accelerate orthodontic treatment?
There is very little clinical research available on the effectiveness of non-surgical interventions.This indicates a gap in knowledge regarding alternative acceleration methods.
36
What does the systematic review say about piezocision in orthodontic treatment?
Piezocision is effective in accelerating the rate of canine retraction.However, the effects may vary and require further investigation.
37
What are some methods to accelerate tooth movement in orthodontics?
Micro-osteoperforations to enhance the rate of tooth movement.Vibrational devices that influence orthodontic tooth movement.Electric toothbrushes used as a vibration method for tooth movement.Piezocision, a minimally invasive procedure for accelerated tooth movement.
38
What are the effects of electric currents on orthodontic tooth movement?
Electric currents can increase the rate of tooth movement.They promote changes in periodontal cyclic nucleotide levels.Combined force and electric current can enhance bone remodeling.
39
What are the findings of studies on vibrational devices in orthodontics?
Vibrational devices have been shown to affect the rate of tooth movement.A systematic review indicates varying effectiveness across different studies.
40
What is Piezocision in orthodontics?
A minimally invasive technique to accelerate orthodontic tooth movement.It involves creating small incisions in the periodontal tissue.
41
What is the relationship between orthodontic treatment and gingival health?
Orthodontic treatment can impact gingival health positively or negatively.Studies suggest a need for careful monitoring during treatment.
42
What are the implications of using Damon3 self-ligated brackets?
They may reduce the duration of treatment compared to conventional brackets.Clinical trials assess their effectiveness in extraction patients.
43
What role do therapeutic modalities play in orthodontic tooth movement?
New therapies aim to modulate the biological response to orthodontic forces.They can potentially enhance the efficiency of tooth movement.
44
What are the effects of force-induced Adrb2 in periodontal ligament cells?
It promotes tooth movement in response to applied forces.Research indicates its significance in orthodontic treatment outcomes.
45
What are some factors that influence the acceleration of orthodontic tooth movement?
Carboxyl-terminal parathyroid hormone fragments stimulate osteoclast-like cell formation.Local RANKL gene transfer to periodontal tissue accelerates tooth movement.1,25-dihydroxyvitamin D3 enhances bone formation for tooth stabilization.Vibration devices have been shown to affect the rate of tooth movement.
46
What are the effects of different substances on orthodontic tooth movement?
Prostaglandin E2 has been compared to 1,25 dihydroxycholecalciferol for their effects on tooth movement.Local administration of osteocalcin influences experimental tooth movement.Corticision affects paradental remodeling during orthodontic tooth movement.
47
What surgical techniques are used to correct occlusal abnormalities?
Surgical operations on the alveolar ridge are performed to correct occlusal issues.Dentoalveolar distraction osteogenesis is used for rapid canine retraction.
48
How does vibratory stimulation impact orthodontic treatment?
Vibratory stimulation has been shown to increase the rate of orthodontic tooth movement.A systematic review and meta-analysis evaluated the performance of vibration devices.
49
What experimental studies have been conducted on tooth movement?
Studies have examined the effects of prostaglandin administration on tooth movement.Research has focused on interseptal bone reduction and its impact on maxillary canine retraction.
50
What are the findings related to local injections in orthodontics?
Local injection of 1,25-dihydroxyvitamin D3 enhances bone formation after tooth movement.Local administration of osteocalcin has been studied for its effects on tooth movement.
51
What role does RANKL play in orthodontic tooth movement?
RANKL gene transfer to periodontal tissue has been shown to accelerate tooth movement.It is involved in the regulation of osteoclast activity during orthodontic treatment.
52
What are some methods to accelerate tooth movement during orthodontic treatment?
Use of self-ligating brackets compared to conventional twin brackets.Application of pulsed electromagnetic fields.Micro-osteoperforations to enhance movement rates.Local application of prostaglandins like PGE1.Continuous infusion of parathyroid hormone (PTH).
53
What are the findings of studies comparing self-ligating and conventional appliances?
Self-ligating appliances may improve alignment efficiency.They can affect the rate of space closure in adolescents.Some studies show no significant difference in intermolar distance effects.
54
What role do biological factors play in orthodontic tooth movement?
Prostaglandin E2 has been shown to influence tooth movement and root resorption.Calcium gluconate may also affect the rate of movement.Hormonal treatments like PTH can enhance movement in experimental settings.
55
What are the implications of using micro-osteoperforations in orthodontics?
They may significantly increase the rate of tooth movement.Systematic reviews suggest positive outcomes in treatment efficiency.
56
What are the effects of different orthodontic treatments on treatment time?
SureSmile technology may reduce treatment time compared to conventional methods.Comparative studies assess efficiency in various appliance types.
57
What is the significance of the 'surgery first' approach in orthodontics?
It allows for immediate skeletal correction in Class III malocclusions.Utilizes the Skeletal Anchorage System for effective results.
58
How do studies assess the impact of orthodontic appliances on adolescents?
Randomized controlled trials compare self-ligating and conventional appliances.Focus on outcomes like alignment efficiency and space closure.
59
What are the potential effects of pulsed electromagnetic fields on orthodontic treatment?
They may accelerate tooth movement during treatment.Research indicates positive outcomes in orthodontic efficiency.
60
What are the findings regarding the use of prostaglandins in orthodontics?
Prostaglandins can enhance orthodontically induced tooth movement.Studies show varying effects on root resorption and movement rates.
61
What are the key findings from the systematic review on micro-osteoperforations?
They can significantly enhance the rate of orthodontic tooth movement.Meta-analysis supports their effectiveness in treatment protocols.
62
What are the ideal properties of adhesives and cements used in orthodontics?
Strong bonding capability to various dental materials.Biocompatibility to ensure safety for patients.Resistance to moisture and temperature changes.Ease of application and manipulation during procedures.
63
What types of glass ionomer cements (GIC) are commonly used in orthodontics?
Conventional glass ionomer cements, known for their fluoride release.Resin modified glass ionomer cements, which offer improved strength and aesthetics.Glass polyphosphonate cements, providing a different bonding mechanism.
64
What is the role of bonding adhesives in orthodontic treatments?
To securely attach brackets and bands to teeth.To ensure a durable bond that withstands forces during orthodontic treatment.
65
What are the different types of primers used in orthodontic bonding?
Resin primers, which enhance adhesion to tooth surfaces.Moisture-insensitive primers, suitable for wet environments.Self-etching primers, which simplify the bonding process by etching and priming in one step.
66
How is tooth preparation important for orthodontic bonding?
It ensures a clean and roughened surface for better adhesive bonding.Proper preparation minimizes the risk of bond failure during treatment.
67
What considerations are there for bonding in cases of fluorosis?
Special techniques may be required to enhance bond strength on affected enamel.Use of specific adhesives that can better adhere to compromised surfaces.
68
What materials are used for impressions in orthodontics?
Silicone impression materials, known for their accuracy and ease of use.Acrylic materials for removable appliances, providing flexibility and comfort.
69
What is the significance of pre-coated brackets in orthodontics?
They simplify the bonding process by eliminating the need for additional adhesives.They can improve the efficiency of orthodontic procedures.
70
What are the advantages of using antibacterial composite adhesives?
They help reduce the risk of bacterial growth around orthodontic appliances.They can enhance the longevity of the bond by preventing decay.
71
What is the purpose of orthodontic banding?
To provide anchorage for orthodontic appliances during treatment.To distribute forces evenly across the dental arch.
72
What are the ideal properties of orthodontic adhesives and cements?
Cost-effective and antimicrobial effect.Non-irritant to oral tissues and ease of handling.Color inconspicuous under brackets with stability in the oral environment.Appropriate working time and convenient curing mode.Easily debonded without harming tooth structure.Low viscosity for penetration and high bond strength.Fluoride releasing potential and good wettability.Command set for immediate bond and low solubility in oral fluids.
73
What are the components of composite materials used in orthodontics?
Resin (BisGMA) and additional monomers like DEGDMA or TEGDMA to reduce viscosity.Filler particles such as glass beads and barium to enhance mechanical properties.Light cure composites may contain urethane dimethacrylate (UDMA) instead of BisGMA.
74
Why are acrylics rarely used for orthodontic bonding today?
Acrylics have decreased bond strength compared to other materials.They are primarily used with plastic brackets in contemporary orthodontics.
75
What are the advantages of using composites in orthodontics?
Composites provide strong bonding for brackets and tubes.They contain inert fillers that reduce polymerization shrinkage and enhance mechanical properties.
76
What is the significance of fluoride releasing potential in orthodontic adhesives?
Fluoride releasing potential helps in preventing dental caries.It contributes to the overall health of the tooth structure during orthodontic treatment.
77
What are the advantages of using pre-coated orthodontic brackets?
Suitable for two-handed dentistry.Better cross-infection control (BEARN et al., 1995).
78
What are the disadvantages of pre-coated orthodontic brackets?
They are expensive.No difference in failure rate compared to uncoated brackets (KULA et al., 2002).
79
What is the role of antibacterial composite adhesive in orthodontics?
Incorporates metacryloyloxydodecylpyridinium bromide (MDPB) to reduce demineralization around brackets.Maintains bond strength while preventing demineralization (BULUT et al., 2007).
80
What are some benefits of contemporary composite materials in orthodontics?
Release fluoride to help prevent demineralization (BUREN et al., 2008).Contain antimicrobial compounds like TiO2 and zinc in bonding resins (POOSTI et al., 2013).
81
What are the characteristics of cyanoacrylates in orthodontic bonding?
Useful for indirect bonding and cures rapidly with moisture.Has a rapid setting time of 5 seconds, which can be a disadvantage for direct bonding.
82
How does the bonding strength of glass ionomer cement (GIC) change over time?
Increases more than 15-20 times after 24 hours (FLORESA et al., 1999).Final bond strength is achieved after 24 hours.
83
What are the findings regarding the bond strength of RMGIC in orthodontics?
Has sufficient bond strength for orthodontic purposes.Similar failure rate to composite materials (SILVERMAN et al., 1995; CHOO et al., 2001).
84
What is the significance of light cure GIC in orthodontics?
Useful in cases with suboptimal etching, such as fluorosis or amelogenesis imperfecta.Considered weak and unreliable as a bonding adhesive (MANDALL et al., 2003).
85
What is the history of glass ionomer cements (GIC) in orthodontic banding?
First introduced in 1972 (WILSON, 1972).Replaced zinc-oxyphosphate and zinc polycarboxylate cements previously used for orthodontic banding.
86
What is the chemical reaction involved in the setting of GIC?
Sets by an acid-base reaction between polyalkenoic acid and fluoroaluminosilicate glasses.Releases aluminum and calcium from the surface during the reaction.
87
What are the main features of conventional glass ionomer?
Consists of liquid and powder leading to an acid-base reaction.The liquid is an aqueous solution of organic acids like poly(acrylic) or poly(maleic) acid.
88
What are the characteristics of conventional glass ionomer cement (GIC)?
Bond strength is less than that of composite resin cements.It is brittle and requires 24 hours to reach maximum strength.Has an unpleasant taste due to acid presence.Moisture contamination can adversely affect the initial set.
89
What distinguishes resin modified glass ionomer cement (RMGIC) from conventional GIC?
RMGIC contains a resin component, HEMA, which can be chemically or light activated.It has twice the overall strength of conventional GIC.Bond failure usually occurs at enamel adhesive interference, reducing adhesive removal on debanding.
90
What are the advantages of using resin modified glass ionomer cement (RMGIC)?
It bonds to tooth structure without needing a dentin bonding agent.More aesthetic than conventional glass ionomers.Less adhesive removal on debanding due to bond failure characteristics.
91
What are the key features of modified composites or compomers?
They contain approximately 30-50% resin and are light cured.They consist of aluminosilicate glasses and carboxyl modified resin monomers.Delayed acid-base reaction occurs in the presence of water, leading to leaching of fluorides.
92
What are the advantages of using compomers in dental applications?
They offer good aesthetics and low solubility.High bond strength and higher fracture toughness compared to conventional materials.
93
What are the disadvantages of using compomers?
Bonding agents are required prior to use.They release less fluoride than glass ionomers.
94
What did the Cochrane review reveal about the bonding of molar tubes and bands?
Failure rates of molar tubes bonded with adhesives were higher than those of molar bands cemented with glass ionomer cement.Less decalcification was observed with molar bands cemented with glass ionomer cement.
95
What are the components and functions of resin primer in orthodontics?
Unfilled resin (methyl methacrylate monomer) that penetrates enamel pores.Achieves micro-mechanical retention, increasing bond strength.Contains Bisphenol-A, which may cause dermatitis in dental professionals.
96
What are the characteristics of moisture-insensitive primers in orthodontics?
Contain hydrophilic primers that bond in moderately wet fields.Example: Transbond MIP by 3M Unitek.Cannot overcome heavy saliva contamination.
97
What are the mechanisms that stop the etching process in self-etching primers (SEPs)?
Acid groups neutralized by forming a complex with calcium from hydroxyapatite.Increased viscosity during airburst slows acid transport to enamel interface.Light curing polymerizes monomers, stopping acid transport.
98
What are the advantages of using self-etching primers (SEPs) in orthodontics?
Less chairside time, saving an average of 23 seconds per bracket.Less enamel loss compared to conventional etching.Minimal discomfort for patients, with no acidic taste or burning sensation.Less moisture sensitive, tolerating some moisture contamination.Similar failure rates of brackets compared to conventional etching.Less discoloration of tooth surface after debonding.
99
What are the disadvantages of self-etching primers (SEPs) in orthodontics?
Bond strength is lower than that of conventional etching.Potential concerns regarding long-term effectiveness.
100
What are the steps involved in chemical surface preparation for porcelain surfaces in orthodontics?
Etch porcelain surfaces using 9.6% hydrofluoric acid for 2-4 minutes or 4% acidulated fluorophosphate for 2 minutes.Apply a silane coupling agent to increase bond strength after etching and drying.Use an intermediate resin like All Bond 2 before bonding with luting cements.
101
What are the mechanical surface preparation methods used in orthodontics?
Roughen the surface using a diamond bur, especially for temporary acrylic crowns.Sandblast with 50 microns aluminum oxide particles for 2-4 seconds.Utilize tin plating or laser etching for surface preparation.
102
What are the main components of alginate used in orthodontic impressions?
Potassium alginate and calcium sulfate form the alginate gel.Sodium phosphate acts as a retarder to extend working time.Potassium sulfate is added as a gypsum hardener.Diatomaceous earth controls viscosity and adds flexibility.
103
What is the setting reaction of alginate in orthodontics?
The setting reaction begins with mixing water, potassium alginate, and calcium sulfate.The reaction produces calcium alginate and a gel-like structure.
104
What precautions should be taken when using acid etchants in orthodontics?
Both hydrofluoric acid and acidulated fluorophosphate are highly erosive and can cause tissue burns.It is essential to protect soft tissues during the etching process.
105
What is the purpose of using a silane coupling agent in orthodontic procedures?
A silane coupling agent is used to increase the bond strength after etching porcelain surfaces.Examples include unhydrolyzed Porcelain Primer by Ormco and prehydrolyzed Scotch prime by 3M.
106
What are the benefits of using alginate as an impression material in orthodontics?
Alginate is easy to manipulate, providing comfort for patients.It is cost-effective and widely accepted by orthodontists.
107
What role do glycols play in the composition of alginate?
Glycols are added to make the alginate powder dustless.This improves handling and safety during the impression process.
108
What is the function of chlorhexidine and ammonium salts in alginate?
Chlorhexidine and ammonium salts serve as disinfectants in alginate formulations.This helps maintain hygiene during the impression process.
109
What are the applications of silicone impression materials in orthodontics?
Used for cleft lip and palate patients.Used for aligners impressions.Fabrication of indirect implant supported appliances.Suitable for patients allergic to alginate.
110
What are the two types of silicone impression materials and their characteristics?
Condensation silicone materials: hydrophobic, require a dry field, and liberate alcohol on setting.Addition silicone materials: can be hydrophilic or hydrophobic, offer better accuracy and dimensional stability.
111
What are the advantages of Polyvinylsiloxanes over alginate?
Superior dimensional stability and tear resistance.Better accuracy and can delay pouring.
112
What are the main features of acrylic used for removable appliances?
Based on methyl methacrylate, which is liquid at room temperature.Undergoes polymerization through the addition of free radicals.
113
How are cold cure acrylics activated and cured?
Activated chemically by mixing monomer liquid with polymer powder.Cured in a hydroflask with warm water under pressure for 10 minutes.
114
What are the limitations of cold-cure acrylics?
Not commonly used due to poor mechanical properties.Less strength and durability, suitable for short-term use only.
115
What initiates the polymerization process in acrylic materials?
The initiator, usually a peroxide like di-benzoyl peroxide.Activated by heat, chemicals, or electromagnetic radiation.
116
What are the viscosities available for Polyvinylsiloxanes?
Light body, regular body, heavy body, and putty.Each viscosity serves different clinical needs in orthodontics and prosthodontics.
117
What are the ideal properties of bonding and banding materials in orthodontics?
Non-irritant and low viscosity.High bond strength and ease of handling.Long working time and convenient curing mode.Antimicrobial and cost-effective.Fluoride releasing potential and good wettability.Color stability and low solubility in oral fluids.
118
What are the advantages of Glass Ionomer Cement (GIC) in orthodontics?
Adhesion to stainless steel and enamel.Release of fluoride and high retentive strength.Easy handling and removal with longer working time.Wet bonding and adequate bond strength when light cured.
119
What is the composition and reaction process of conventional Glass Ionomer Cement (GIC)?
Composed of liquid (aqueous solution of organic acid) and powder (calcium alumino-fluoro-silicate glasses).Mixing leads to an acid-base cement reaction, releasing aluminum and calcium.
120
What are the advantages of Resin Modified Glass Ionomer Cement (RMGIC)?
Bonds to tooth structure without a dentin bonding agent.Transverse strength is twice that of conventional GIC.More esthetic than traditional glass ionomers.
121
What are the characteristics of Compomers in orthodontic materials?
Contain a greater amount of resin (30-50%).Excellent aesthetics and low solubility.High bond strength and higher fracture toughness.
122
What are the disadvantages of Compomers compared to other orthodontic materials?
Require bonding agents prior to use of cement.Release less fluoride than glass ionomers.
123
What are the advantages of Glass Polyphosphonate Cements?
Rapid setting time and high compressive strength.Low solubility, making them durable in oral environments.
124
What are the components of composite bonding adhesives used in orthodontics?
Composed of diacrylates, including BisGMA.May also include diethylene glycol dimethacrylate (DEGDMA) or triethylene glycol dimethacrylate.
125
What are the components of alginate impression materials?
Potassium alginate and calcium sulphate.Sodium phosphate.Potassium sulphate for gypsum hardening.Diatomaceous earth or other fillers to control viscosity.Glycols to make powder dustless.Chlorhexidine and ammonium salts as disinfectants.Coloring and flavoring agents.
126
What are the advantages of using alginate for impressions?
Inexpensive and easy to manipulate.Can be used with stock trays.Pleasant taste and easily poured in gypsum.Adequate working and setting time.
127
What are the disadvantages of alginate impression materials?
Poor tear strength and dimensionally unstable.Tendency to absorb and lose water.Must be poured immediately after taking the impression.Low detail reproduction compared to other materials.
128
What are the two types of silicone impression materials?
Condensation silicone materials.Addition silicone materials (Polyvinylsiloxanes).
129
What are the characteristics of cold cure acrylics?
Self-cure acrylic appliances with less strength and durability.Reduce chance of moisture contamination as they are insoluble in oral fluids.
130
What are the disadvantages of composite materials in dentistry?
Moisture sensitive and technique sensitive.Etching and bonding agents required prior to use.Chemical cured composites have a short working time.No fluoride release or recharge compared to glass ionomer cements (GICs).
131
What is the purpose of acid etching in dental procedures?
37% phosphoric acid is used to etch enamel for 15-60 seconds.Enhances bonding by creating a rough surface for better adhesion.Washed for 20 seconds; pumice is not needed.Sandblasting is reserved for etching on metal or porcelain crowns.
132
What is the function of resin primers in dental bonding?
Unfilled resin (methyl methacrylate monomer) penetrates exposed enamel pores.Improves bond strength between the tooth structure and restorative materials.
133
What are the advantages of self-etching primers (SEPs)?
Less chairside time required and less enamel loss during etching.No rinsing is required, reducing the risk of decalcification.Less moisture sensitivity and discoloration compared to traditional methods.
134
What is the active ingredient in self-etching primers and its function?
Methacrylate phosphoric acid ester dissolves calcium from hydroxyapatite.This process enhances bonding in wet fields, making it effective in moist conditions.
135
What are the advantages of using heat cured acrylic in orthodontics?
Strong and durable, allowing for thin section appliances.Preferred material for constructing functional appliances, retainers, and distalization appliances.
136
What are some key studies related to orthodontic bonding techniques?
ALJUBOURI et al. (2004) compared self-etching primer with two-stage etch for bonding.BARRY (1995) investigated the effects of omitting pumice prophylaxis on bond failure rates.
137
What factors influence the bond strength of orthodontic brackets?
Etch time and debond interval significantly affect shear bond strength (BIN ABDULLAH & ROCK, 1996).Use of antibacterial adhesives can enhance bond strength (BULUT et al., 2007).
138
What is the role of self-etching primers in orthodontics?
They simplify the bonding process by eliminating the need for separate etching and priming steps.Studies show varying effects on bond strength and the necessity of pumicing (BURGESS et al., 2006).
139
How does enamel sealant affect enamel demineralization?
Pro Seal has been shown to inhibit enamel demineralization in vitro (BUREN et al., 2008).This can be beneficial in maintaining enamel integrity during orthodontic treatment.
140
What are the implications of water and saliva contamination on orthodontic bonding?
Contamination can negatively affect the shear bond strength of bonding agents (CACCIAFESTA et al., 2003).Resin-modified glass ionomers may be more resilient to such contamination (CHOO et al., 2001).
