Dental Materials Final Review

A veneer is a thin layer of material that covers another material. In dentistry, it is a restoration that is placed on the facial surface of anterior teeth to cover, or "veneer" esthetic problems. A buildup (core) is when the crown of a tooth is broken down to the point of needing to be "rebuilt" to hold the final restoration. A coping is the metal substructure that supports the porcelain layers in a ceramometal restoration. A pontic is a replacement tooth.

The wax rims used for denture construction serve multiple purposes. They help determine the patient's midline, which is the imaginary line that divides the upper and lower jaws. They also help establish the plane of occlusion, which is the relationship between the upper and lower teeth when the jaws are closed. Additionally, the wax rims aid in determining the size and positioning of the denture teeth. Therefore, all of the given options are correct.

A provisional crown is the appropriate, professional name (especially used by prosthodontists) for a temporary crown.

The patient must maintain excellent plaque control and practice frequent and effective oral hygiene to ensure longevity of the implant. The dentist would adjust and monitor the occlusion of the implant with the opposing teeth. Fluoride applications at home are not typical for maintenance of implants.

Brackets are secured to the tooth surface by acid etching and coposite resin. Dental cements may be used to secure bands to the tooth (molars). Chemically activated resins are used to make custom trays and denture fabrication and repairs. Ligatures secure the archwire into the bracket slot.

Obturate refers to the filling and sealing of the root canal once the pulp tissue is removed. Accessing the canal means to create an opening through the tooth to the pulp chamber. This is done with a handpiece and bur.

An apicoectomy surgically removes 1-3 mm of the root apex. A retrofill is preparing, filling, and sealing of the apical end of the root. A root resection, another surgical procedure, is the removal of an entire root of a multirooted tooth. Retreatment is root canal therapy performed a second time.

Calcium hydroxide promotes the formation of secondary dentin. Secondary dentin is a protective layer of dentin that forms in response to dental trauma or irritation. Calcium hydroxide stimulates the pulp cells to produce secondary dentin, helping to repair and protect the tooth. Composite cements, silicate cement, and temporary cements do not have the same effect on promoting the formation of secondary dentin.

Amalgam, gold foil, and composite restorations are direct restorations, which means that they are constructed directly in the oral cavity. It usually involves placing the restorative material "directly" into the cavity preparation. Other restorations, such as inlays, onlays, crowns, and bridges are constructed outside of the oral cavity, in a dental laboratory. hence, they are referred to as "indirect" restorations. The term "fixed" is used to designate that it is not removable because it is cemented, or luting, in place. A fixed restoration is not removable by the patient.

irrigants are aqueous solutions used to disinfect the canal system. Common irrigants are sodium hypochlorite, saline, and chlorohexidine gluconate. Paper points are used to dry the root canal. Sealers are a type of cement used to coat the canal and to fill in voids between the canal wall and gutta-percha. Gutta-percha is a polymeric material with zinc oxide and barium sulfate added.

Cements are more soluble than the overlying restoration. This means that cements have a higher tendency to dissolve or break down compared to the restoration material that is placed on top of it. This could be due to differences in composition or chemical properties between the two materials. As a result, cements may require more maintenance or replacement over time compared to the restoration material.

An alveolar ridge having no teeth is said to be edentulous. In most cases, when the mandibular arch atrophies, it becomes smaller in size due to aging. An atrophic edentulous mandible is one that has no teeth, is very "low" and small, and would be adequate to support a denture. The word "iatrogenic" means "caused by a professional by accident" and the word "dentulous" means "with, or having teeth"

Orthodontic brackets are bonded onto the facial surfaces and hold an arch wire in place on each tooth in the arch. The brackets transfer the forces of the wire, springs, and elastics to the teeth. Bands encircle the crown, and are used on molars because they require more force to move compared to other teeth. Retainers are used to prevent relapse after treatment. Composite resin is used to attach the bracket to the tooth surface.

Patients with systemic diseases, such as diabetes, are contraindicated for dental implants. Smokers and patients practicing poor oral hygiene are also poor candidates for implants. Recurrent caries are not associated with contraindications for dental implants.

Polycarboxylate cement is a dental adhesive material that is known for its excellent adhesion properties. It is capable of adhering to various surfaces in the oral cavity, including dentin, enamel, and metal. This makes it a versatile option for dental restorations, as it can be used to bond restorative materials to different tooth structures and metal frameworks. Its ability to adhere to all of these surfaces makes it a preferred choice for dental professionals in various clinical situations.

The scope of practice of the dental hygienist does not include selecting restorative materials for tooth restoration. However, a very important role of the hygienist is patient education, determining the time between dental hygiene visits, and selecting the best auxiliary aids for the patient to achieve optimal plaque removal.

A retainer is a fixed (bonded) or removable appliance to prevent relapse after active orthodontic treatement is completed. A bracket is a small metal, ceramic, or polymer material that has a centered, horizontal slot. the archwire fits into the slot of each bracket, usually across the entire arch. A ligature, either wire or elastic, secures the archwire into the bracket slot.

endosseous or tooth form implants are screwed or pressed into a cut hole in the bone. Transosseous or staple implants include a plate and bolts that go through the mandible in the anterior region. Subperiosteal implants involve two surgeries, an impression, cast, and a metal framework.

Changing a porcelain powder to a solid is called sintering. The powder is not melted, so the shape of the restoration is maintained. Burnishing involves pushing the metal toward the tooth to close gaps between the casting and the tooth. Investing is covering a wax pattern mounted in a casting ring with mixed gypsum product (investment)

Cross-linking of acrylic resins refers to the process of chemically bonding the polymer chains together, creating a three-dimensional network. This cross-linking enhances the strength and durability of the resin, resulting in improved mechanical properties. In this case, the most important property that would be improved by cross-linking is toughness. Toughness refers to the ability of a material to absorb energy and deform without fracturing. By cross-linking the acrylic resins, the material becomes more resistant to cracking and breaking, making it tougher and more durable.

surgical silk suture is nonabsorbable and must be removed at a later appointment. Absorbable sutures are usually placed on the inside of the body, and since the body resorbs them, a later appointment for removal is not necessary. Surgical gut suture is one type of absorbable suture.

Porcelain has outstanding esthetic properties, such as translucency and life-like appearance. It is very brittle, however, and may fracture when subjected to high occlusal forces. It is recommended for veneers and low-stress crowns for anterior teeth, such as maxillary lateral incisors.

The first statement is true because the patient's home care regimen for implant maintenance can indeed consist only of a toothbrush and floss. This is a common and effective method for maintaining oral hygiene around implants. The second statement is also true because without proper maintenance, the possibility of implant failure does increase. Regular and proper care, including brushing and flossing, is necessary to prevent complications and ensure the long-term success of dental implants.

ZOE (Zinc Oxide Eugenol) is a dental material commonly used for temporary fillings and cementing crowns. It is known for its obtundent properties, which means it helps to soothe and calm the dental pulp. Additionally, it provides a temporary protective barrier for the pulp. However, one property that does not apply to ZOE is that it releases fluoride. Unlike some other dental materials, ZOE does not have the ability to release fluoride ions, which are beneficial for preventing tooth decay.

Inlay wax is used for casting procedures. It leaves no residue in the burnout process and has a higher melting temperature. It is also harder than other dental waxes. Sticky wax is also a hard wax that melts at a higher temperature, but this wax is used as an "attachment medium" such as attaching a sprue to a pattern. Boxing wax is used to pour impressions, and baseplate wax is used in the fabrication of dentures.

"Denture set up" refers to the process of setting the denture teeth in wax. This involves arranging the artificial teeth in the desired position and alignment within the wax base of the denture. This step is crucial in creating a properly fitting and functional denture before it is finalized and fabricated.

A maxillary denture is much easier to wear than a mandibular denture because of the extension of the borders of the denture (which helps to create the seal) and larger surface bearing area. Saliva halps to achieve the seal and improve the suction.

When glass ionomer is mixed too slowly, the resulting mix becomes thick. This is because glass ionomer is a self-curing material, meaning it sets and hardens on its own without the need for additional curing agents or external factors. Mixing it slowly prevents the proper incorporation of the powder and liquid components, leading to a thicker consistency. A slow mixing process does not allow for the proper dispersion and hydration of the glass particles, resulting in a thicker and less workable mixture.

Both statements are true. The first statement states that all debonding methods remove some enamel, which is true as debonding involves removing the resin material from the enamel surface. The second statement states that it is the responsibility of the hygienist to select the least traumatic method of resin removal, which is also true as the hygienist is responsible for choosing the method that causes the least damage to the enamel during the debonding process.

For permanent molars, a pulpotomy is a temporary procedure and is followed by root canal therapy. For primary molars, it is a permanent procedure and is restored with a stainless-steel crown. This will maintain space and function until the permanent molar takes its place.

The gypsum investment material that comprises the mold must be expanded to compensate exactly for the shrinkage of the metal casting. Otherwise, the cast restoration will not fit the preparation of the patient's tooth.

It is true that castable glass is one type of all-ceramic restoration. All-ceramic restorations are not superior to ceramometal materials in the aspect of strength, however, and that makes the second statement false.

A macrofilled composite has the advantage in that when fixed appliances are removed at the end of treatment (debonding), it is much eassier to locate residual composite bonding material. Macrofilled composites are rough and turn gray when the composite material is abraded with a metal instrument.

Bonding porcelain to metal in a ceramometal restoration provides a precise fit to the prepared tooth structure. The disadvantage is the opacity, because of the metal. There is no difference between all ceramic or ceramometal crown in the pateints ability to remove plaque.

Today's denture teeth are usually acrylic rather than porcelain. Porcelain teeth are, however, harder than acrylic teeth and cause excessive wear to the natural opposing teeth.

During debonding, the direction of the stroke of the bur should be towards the incisal or occlusal surface. This means that the bur should be moved in a direction away from the gingival margin, proximal surface, and embrasure spaces. Moving the bur in this direction ensures that the bond between the material and the tooth is broken effectively without causing any damage to the surrounding structures.

The disadvantage of using polycarboxylate cement is its lack of strength. This means that the cement may not be able to withstand high forces or pressure, making it less durable compared to other dental materials. This weakness can potentially lead to premature failure or damage to the restoration, requiring additional repairs or replacements.

Zinc phosphate cement should be used as much as possible on the slab during mixing to reduce the exothermic reaction. This is because zinc phosphate cement has a high exothermic reaction, meaning it generates a significant amount of heat during the setting process. By using as much of the area on the slab as possible, the heat generated by the cement can be spread out and dissipated more effectively, reducing the risk of thermal damage to the surrounding tissues.

To avoid unnecessary use of the bur during the debonding procedure, it is recommended to apply air frequently and examine the surface. This helps in detecting any remaining resin or adhesive on the teeth, allowing for targeted and efficient use of the bur. By applying air, any residual material can be visualized and identified, reducing the need for excessive bur use. Regular examination of the surface ensures that only the necessary areas are treated, minimizing the risk of overuse of the bur.

A healing cap is placed on the implant during the second surgery. It extends out of the mucosa into the oral cavity. Once this heals and epithelial tissues are formed, the healing cap is removed, and an abutment is placed. Impressions may be necessary before treatment is completed, but they are not taken during the second surgery. Osseointegration is not measured during either surgery.

When repairing a broken denture, a thin layer is ground off to create a smooth surface for the repair. Applying a monomer to the surfaces helps in dissolving some of the set material. This is beneficial because it allows the repair material to bond effectively with the existing denture, ensuring a strong and durable repair. Additionally, dissolving some of the set material helps in accelerating the setting reaction of the repair, reducing the overall repair time. It also makes the finishing and polishing of the repair easier, resulting in a seamless and aesthetically pleasing outcome. Lastly, by dissolving some of the set material, the color of the resin powder used for the repair remains unchanged, maintaining a consistent appearance.

The correct answer is that the acrylic resin must flow through and around the mesh of the framework. This is different from the processing of a complete denture because in a partial denture, the acrylic resin needs to flow around and attach to the metal framework that supports the artificial teeth. This ensures proper fit and stability of the partial denture. In contrast, a complete denture does not have a framework, so the processing technique does not involve the resin flowing through and around a mesh structure.

Lateral condensation is used to fill the root canal with gutta-percha. Condensation is a term used in dentistry to describe the method of compressing and filling a small area in a tooth, such as a preparation or root canal. Of all the answers, this one is most appropriate.

The mold (investment) must expand and provide compensation for the metal contraction during casting. The main, obvious purpose of the investment, however, is to create a mold from the wax pattern in the casting process.

During debonding, it is important to remove all composite resin material to avoid complications such as gingival inflammation, stain, and plaque accumulation. However, changes in occlusion are not directly related to the presence or absence of composite resin material, but rather to the overall alignment and positioning of the teeth. Therefore, changes in occlusion would not be an exception in this case.

A subperiosteal implant is placed on the mandibular bone below the periosteum, which is the outer layer of the bone. This type of implant involves two surgical procedures, suggesting that it is a more complex and involved process compared to the other options. Endosseous implants are placed directly into the bone, transosseous implants go through the bone, and staples are not typically used for dental implants. Therefore, the correct answer is subperiosteal.

precious metals include the noble metals and silver. The noble metals are gold, platinum, and palladium. Non-precious metals are those that do not contain any noble elements. High-noble metals contain 60% or more gold and other noble elements.

A tapered plain-cut finishing bur is used to remove excess material and smooth the surface of a restoration. Using a low speed hand piece allows for more control and precision during the debonding process. The low speed hand piece reduces the risk of damaging the restoration or surrounding teeth. Using a high speed hand piece may generate excessive heat and vibration, which can lead to fractures or damage to the restoration. Therefore, the correct combination for debonding is a tapered plain-cut finishing bur and a low speed hand piece.

Glass ionomer and ZOE (Zinc Oxide Eugenol) are dental cements that are commonly used for caries control. Glass ionomer cements are tooth-colored and have good adhesion to both enamel and dentin. They release fluoride ions, which help in remineralizing the tooth structure and preventing further decay. ZOE cement contains zinc oxide and eugenol, which have antibacterial properties and can provide temporary relief from tooth sensitivity. Using a combination of glass ionomer and ZOE cement can provide both long-term caries control and temporary relief from symptoms.

It is true that titanium is very difficult to cast and does not have high strength compared to other metals. The strength of titanium is adequate for implants. However, it will osseointegrate to bone.