Single and Multiple Tooth Replacement: Treatment Options

Single and Multiple Tooth Replacement: Treatment Options by Randolph R. Resnik and Neil I. Park

Introduction

Dental implants have broadened the scope of restorative options for patients, enhancing form, function, and esthetics.
Patients now have more choices than traditional fixed bridges or removable prosthetics for missing teeth or extractions.
Implants can minimize bone loss following tooth extraction, offering a solution closer to ideal dental health.
Clinicians must educate patients on all available therapeutic options with their advantages and disadvantages, fulfilling ethical and legal obligations.
This chapter aims to provide a comprehensive treatment protocol for common edentulous conditions.
Informing patients about all options, including no treatment, empowers them to make educated decisions aligning with their needs and values.

Tooth Replacement

70% of the dentate population in the United States is missing at least one tooth.
Single-tooth replacement is expected to become a larger part of prosthetic dentistry.
In 1960, the average American over 55 had only seven original teeth; now, the average 65-year-old has 18 natural teeth.
Baby boomers (born 1946-1964) are expected to have at least 24 natural teeth by age 65.
Clinicians should use evidence-based medicine, incorporating the best literature and research, for tooth replacement decisions.
External clinical evidence can invalidate accepted treatments, leading to the adoption of more effective and safer modalities.
Treatment planning should be evidence-based.
Clinicians should avoid favoring treatments based on personal preferences and discuss all options with their respective advantages and disadvantages.
Most state dental boards mandate informing patients of all viable options.

Treatment Options for a Single Edentulous Site

Five possible treatment options exist for replacing a single missing tooth:
1. No treatment
2. Removable partial denture
3. Resin-bonded prosthesis
4. Fixed partial denture
5. Implant
Interocclusal space is critical and must be carefully assessed.
Insufficient vertical space may contraindicate any prosthesis without prior correction of the occlusal plane and maxillomandibular relationships.
The condition, prognosis, and angulation of adjacent teeth must be evaluated to rule out contraindications.

No Treatment

The option of no treatment should always be presented, even though it is often not ideal.

Advantages

No further procedures are required.
No financial demands on the patient.

Disadvantages

Numerous consequences may result, leading to occlusal disharmony and further dental complications.
Movement of Adjacent Teeth: Teeth distal to an extraction site, anterior to the second molars, will tilt mesially into the edentulous space, altering the occlusal plane.
Mesial tilt changes the direction of load, potentially causing excessive stress to the periodontal ligament.
Opposing teeth will supraerupt in response to changes in the occlusal plane, possibly requiring orthodontic or endodontic/crown therapy, or even extraction.
Occlusal Force Issues: Patients tend to favor the fully dentate side for chewing, reducing masticatory efficiency on the partially edentulous side.
Overuse of the fully dentate side can lead to fatigue-related issues, such as fractures of crowns/enamel/restorations, significant occlusal wear, or myofascial pain syndrome.

Removable Partial Denture (RPD)

Advantages

Convenience: Tooth-borne RPDs can be received after a few appointments.
Non-invasive: Does not require invasive treatment.
Lower cost compared to other options.

Disadvantages

Decreased Acceptance: Low patient acceptance rate compared to other treatments.
Difficulty eating due to food debris trapped under the prosthesis.
Disrupted speech patterns due to acclimation to the partial framework.
Bulky prosthesis covering palatal (maxilla) or lingual (mandible) tissue.
Increased Morbidity to Abutment Teeth: RPDs often lead to deterioration of the remaining dentition and surrounding oral tissues.
A study indicated that conventional RPDs had a 40% success rate at 5 years and 20% at 10 years, with abutment tooth repair as the indicator of failure.
Patients may experience greater mobility of abutment teeth, increased plaque retention, bleeding on probing, higher caries incidence, speech inhibition, taste inhibition, and noncompliance.
Abutment tooth loss from RPDs may be as high as 23% within 5 years and 38% within 8 years (Shugars et al.).
Increased Bone Loss: Abutment teeth are subjected to additional lateral forces.
Compromised periodontal support can lead to partial dentures designed to minimize forces, increasing prosthesis mobility and soft tissue support.
Bone loss is accelerated in soft tissue support regions compared to patients not wearing partials.
Accidental Swallowing of Prosthesis: One-tooth RPDs (Nesbit) lack cross-arch stabilization, leading to potential swallowing or aspiration.
Numerous case reports discuss inadvertent swallowing, necessitating medical treatment.

Conclusion

Evidence-based evaluation does not ideally indicate RPDs for single edentulous sites.
Partial dentures may accelerate the loss of adjacent teeth and continued bone loss, predisposing patients to increased morbidity.

Resin-Bonded Fixed Partial Denture (Maryland Bridge)

An option for replacing a missing tooth by bonding a pontic to adjacent teeth.
Conservative treatment, but not usually the first choice due to unpredictable longevity.

Advantages

Conservative Treatment: Requires almost no tooth preparation, usually limited to the enamel.
Reversible Treatment: The prosthesis can usually be removed without damaging abutment teeth; useful as an interim treatment.
Conventional, Fast Treatment: Minimal appointments, involving a conventional or digital impression followed by insertion.
Inexpensive: Reduced overhead costs, laboratory bills, and chair time.

Disadvantages

Higher Failure Rate: Higher debond rate compared to conventional bridges.
Most reports indicate a failure rate of at least 30% within 10 years, and as high as 54% within 11 months.
Most failures occur from cement (bonding) failure during function.
Higher Recurrent Caries: Highly susceptible to partial or total dislodgement, leading to decay.
Nonideal Space: Diastemas or pontic spaces that are too large or small can cause difficulty in space distribution and esthetic issues.
Relapse of Abutment Teeth: Partial dislodgement may result in movement of abutment teeth, especially after orthodontic treatment.

Fixed Partial Denture (FPD)

Historically, the most common treatment for a single missing tooth, involving the preparation of adjacent teeth.
High success rates have made FPDs a preferred treatment since the 1950s.

Advantages

Common Type of Treatment: Conventional procedure that most clinicians are comfortable performing.
Fabricated quickly; satisfies criteria of normal contour, comfort, function, esthetics, speech, and health.
Increased patient compliance, especially due to no need for surgical intervention.
Minimal Need for Soft and Hard Tissue Augmentation: Augmentation of the edentulous area is uncommon.
Surgical augmentation procedures are usually not needed, as the pontic can be modified to encompass any defect.

Disadvantages

Increased Caries Rate: Caries and endodontic failure of abutment teeth are common causes of FPD failure.
Caries occurs more than 20% of the time, and endodontic complications occur 15% of the time.
Caries primarily occur on the margin next to the pontic, which acts as a plaque reservoir due to limited flossing.
Long-term periodontal health of abutment teeth is at greater risk due to increased plaque, including bone loss.
Increased Endodontic Treatment: Vital tooth preparation for a crown has up to a 6% chance of irreversible pulpal injury requiring endodontic treatment.
Crown margin next to the pontic is at greater risk for decay, causing the need for endodontics.
Up to 15% of abutment teeth for a fixed restoration require endodontic therapy, compared with 6% of nonabutment teeth with crown preparations.
Unfavorable Outcomes of Fixed Partial Denture Failure: May include the need to replace the failed prosthesis, loss of an abutment tooth, and the need for additional pontics and abutment teeth in the replacement bridge.
Endodontic therapy is not 100% successful, with meta-analysis reports at 90% success at the 8-year mark.
Approximately 15% of FPD abutment teeth require endodontics, leading to potential tooth loss.
Endodontic posterior tooth abutments are at greater risk for fracture.
Reports indicate abutment teeth for an FPD fail due to endodontic complications (e.g., fracture) four times more often than those with vital pulps.
Abutment teeth may be lost from caries, endodontic complications, or root fracture at rates up to 30% for 8 to 14 years.
Recent reports indicate 8% to 18% of the abutment teeth retaining an FPD are lost within 10 years.
80% of abutments have no previous decay or are minimally restored before FPD fabrication.

Single-Tooth Implant

Implants can provide a long-term solution rather than focusing primarily on treatment time, cost, or difficulty.

Advantages

Higher Success Rate: Single-tooth implants have become the most predictable method of tooth replacement since the late 2000s, with success rates exceeding 95%.
Hygiene: Easier hygiene as the proximal surfaces are easily accessed for flossing, preventing periodontal and carious pathologies.
No Alteration of Adjacent Teeth: Decreases the risk for recurrent caries or endodontic issues in these teeth.
Patients are at a much lower risk for losing further teeth in the future.
Better Cost Comparison: Cost comparison studies demonstrate a more favorable cost-effectiveness ratio.
Conventional FPDs often need replacement every 10 to 20 years due to decay, endodontic complications, porcelain fracture, or unretained restoration.
Higher Survival Rate: Single-tooth implant exhibits the highest survival rates of the five treatment options presented.
Adjacent teeth have the highest survival rate and the lowest complication rate.

Disadvantages

Increased Treatment Time: Longer treatment time than RPD or FPD, with an average implant requiring 3 to 6 months for osseointegration, depending on bone density and volume.
Immediate placement and loaded implants are popular but have limitations.
Possible Need for Additional Treatment: Soft tissue modifications may be necessary in esthetic areas to change the soft tissue drape or enhance the tissue biotype.
Hard tissue (bone) may require augmentation for ideal implant placement and long-term success.
Esthetics: The final prosthesis may feature a traditional tooth contour (FP1), a longer crown form (FP2), or may require the addition of pink porcelain/zirconia to mimic normal soft tissue contours (FP3).
Patient awareness of these possible prosthetic outcomes is crucial, as their esthetic values may dictate the need for adjunctive bone grafting procedures.

Conclusion

Single-tooth implant exhibits the highest survival rates among treatment options presented.
Adjacent teeth have the highest survival rate and lowest complication rate.

Specific Single-Tooth Implant Indications

Anodontia

The absence of one or more teeth, may be complete (rare) or partial (hypodontia).
Partial anodontia (excluding third molars) is often due to familial heredity, with an incidence rate ranging from 1.5% to as high as 10% in the U.S. population.
Congenital absence occurs less often in Asians and African Americans (2.5%) than in whites (5.15%).
Highest average has been reported in Scandinavian countries (10.1% in Norway and 17.5% in Finnish Skolt-Lapps).
Ectodermal dysplasia is the most common syndrome associated with multiple missing teeth.
A high correlation exists between primary tooth absence and a permanent missing tooth.
The mandibular second premolar is most often missing (38.6%), followed by the maxillary lateral incisor (29.3%), the maxillary second premolar (16.5%), and the mandibular central incisor (4.0%).
The missing mandibular second premolar primarily occurs in male patients, and the missing maxillary lateral incisor primarily occurs in female patients.
Maxillary lateral incisors are the most common multiple teeth lost (other than third molars), followed by mandibular and maxillary second premolars.
Fewer than 1% of individuals are missing more than two teeth, and fewer than 0.5% are missing more than five permanent teeth.
Most children with more than five teeth missing have ectodermal dysplasia.
A congenital missing mandibular second premolar most often has a deciduous second molar.
The deciduous second molar may be extracted around age 5–6, allowing the permanent molar to erupt in a more mesial position.
Alternatively, when the first deciduous molar is lost naturally (around age 9–11), the first permanent premolar and first molar may be orthodontically positioned adjacent to each other, negating the need for a second premolar replacement.
Few disadvantages exist to orthodontic space elimination.
Deciduous second molars may break down and need extraction.
If maintained, deciduous teeth may become ankylotic approximately 10% of the time. This leads to overeruption of the opposing maxillary second premolar and teeth tipping over the deciduous tooth.
Because the deciduous molar is 1.9 mm larger than a premolar, the implant site may require bone augmentation.
An implant is usually the treatment of choice.
An alternative is orthodontic closure of the space with a transitional anchorage device to prevent anterior teeth from shifting distally.

Single-Tooth Implant Size Specifics

The ideal diameter depends on the mesiodistal dimension of the missing tooth and the buccolingual dimension of the implant site.
Specific guideline measurements:
- 1. 5–2.0 mm from an adjacent tooth
- 3. 0 mm between implants
- 2 mm from a vital structure
- 1. 5–2.0 mm of buccal bone (after implant placement)
- 1. 0 mm of lingual bone (after implant placement)
Exercise caution when placing implants with compromised facial bone.
Thickness less than 1.0 mm increases risk for bone loss and implant failures.

Anterior Teeth Replacement

Mandible

Mandibular anterior edentulous areas are difficult to treat due to compromised mesial-distal length.
Placing one implant for each missing tooth is often impossible.
For two missing mandibular incisors, one implant may be placed interproximally, slightly lingual, with a screw-retained prosthesis.
For four missing lower incisors, two implants may be placed interproximally, with equal cantilever distribution.
For missing mandibular cuspid to cuspid, four implants are usually placed, with distal implants in the #22 to #23 and #26 to #27 embrasure areas.

Maxillary

Maxillary anterior edentulous spaces are one of the most difficult treatment areas.
Replacing the tooth is essential, and financial aspects are secondary.
Patients are more anxious and seek alternatives to preparing adjacent teeth for FPD abutments.
Anterior FPD restorations are often perceived as less esthetic than natural teeth.
A common site for a single-tooth implant in a restorative practice is the maxillary central or lateral incisor.
The highly esthetic zone of the premaxilla requires both hard (bone and teeth) and soft tissue restoration, with soft tissue drape often the most difficult aspect.
Recently, studies of anterior single-tooth implant replacement with osteointegrated implants are more prevalent.
Studies show that single-tooth implant restorations are successful.
Single-tooth implants improve adjacent teeth prognosis compared to other options.
The maxillary anterior single-tooth implant has become the treatment choice when bone and space parameters are sufficient or may be created.
Single-tooth replacement is common in implant dentistry.
High patient expectations, esthetic requirements, and sensitive soft and hard tissue management compound the complexity of anterior teeth restoration.
Implants to replace a maxillary anterior single tooth remain one of the more difficult treatments to perform in implant dentistry.

Posterior Teeth Replacement

Premolar Replacement

The most ideal and easiest posterior tooth to replace with an implant is the maxillary first premolar.
The canine is at increased risk for material fracture or uncementation when used as an abutment for a three-unit FPD.
Vertical available bone is usually greater than in any other posterior tooth positions.
Almost always anterior or below the maxillary sinus and is perfect for clinicians learning implant placement.
In the mandible, the first premolar is almost always anterior to the mental foramen and associated mandibular neurovascular complex.
The bone trajectory for implant insertion is more favorable than for any other tooth in the arch.
The maxillary premolars are often in the esthetic zone.
Bone grafting is common before maxillary first premolar implant placement because the extraction of the thin buccal root often results in facial bone loss.
To avoid the need for a crown with a ridge lap, the implant body is often positioned under the buccal cusp tip (one-third buccal, two-thirds lingual) rather than midcrest.
The natural premolar tooth is 7 mm wide in the mandible and 6.5 to 7 mm in the maxilla.
The premolar root is usually 4.2 mm in diameter on average at a distance of 2 mm below the cement-enamel junction (CEJ), which is the ideal position of the bone.
The most common implant diameter is usually 4 mm at the crest module.
When the mesiodistal dimension is only 6.5 mm, a 3.5 mm implant is suggested.
The maxillary canine root is often angled 11 degrees distally and presents a distal curve 32% of the time, which may extend over the shorter root of the maxillary first premolar.
The surgeon may inadvertently place the implant parallel to the second premolar and, consequently, into the natural canine root.
A tapered implant body at the apical third may also be of benefit to avoid encroachment on the apical region of the canine.
The second premolar root apices may be located over the mandibular neurovascular canal (or foramen) or maxillary sinus.
A shorter implant than ideal is a common consequence in the second premolar site.

First Molar Implant Replacement

One of the most common teeth to be extracted.
The natural molars receive twice the load of the premolars and have 200% more root surface area.
The mesiodistal dimension usually ranges from 8 to 12 mm.
The ideal size of the implant should be measured by the intra-tooth distance from the adjacent CEJ of each tooth, avoiding food impaction.
When one 4-mm-diameter implant is placed to support a crown with a mesiodistal dimension of 12 mm, this may create a 4- to 5-mm cantilever on the marginal ridges of the implant crown.
The magnified occlusal forces may cause bone loss, increase abutment screw loosening, and increase abutment or implant failure because of overload.
Sullivan reported a 14% implant fracture rate for single molars fabricated on 4.0-mm implants composed of grade 1 titanium.
Rangert et al. reported that overload-induced bone resorption appeared to precede implant fracture in a significant number of 4.0-mm-diameter single-molar implant restorations.
A larger-diameter implant should be inserted to enhance the mechanical properties of the implant system through increased surface area, stronger resistance to component fracture, increased abutment screw stability, and enhanced emergence profile for the crown.
When the mesiodistal dimension of the missing tooth is 8 to 12 mm with a buccolingual width greater than 7 mm, a 5- to 6-mm-diameter implant body is suggested.
Langer et al. also recommended the use of wide-diameter implants in bone of poor quality or for the immediate replacement of failed implants.
When the mesiodistal dimension of the missing tooth site is 14 to 20 mm, two 4- to 5-mm-diameter implants should be considered to restore the region.
Bahat et al. reported the results of various implant numbers and size selections, with a 1.2% overall failure rate.
Balshi et al. compared the use of one implant and two implants to replace a single molar; the two-implant group exhibited a lower complication rate than the one-implant group.
Geramy and Morgano showed a 50% decrease in mesiodistal and buccolingual stress between 5-mm and standard-diameter implants; the double-implant design had the least stress of all.
When the posterior space is 14 to 20 mm, the largest implant diameter for the two implants is calculated by subtracting 6 mm from the intratooth distance and dividing by 2 to determine the size of each implant.
Ideally, two implants should be 3 mm apart because crestal bone loss around each implant may occur.
When the mesiodistal space is 12 to 14 mm from adjacent CEJs, the treatment plan is less obvious; primarily try to obtain 14 mm of space.
Implants may not be centered in the crestal width of bone to help obtain that space.

Second Molar Implant Replacement

When third molars are missing, the second mandibular molar is usually not restored.
The mandibular second molar is not in the esthetic zone of patient.
Ninety percent of the masticatory efficiency is generated anterior to the mesial half of the mandibular first molar, so function is rarely a primary reason to replace the second molar.
A 10% greater occlusal force is measured on the second molar compared with the first, increasing biomechanical stress–related complications.
The crown height space decreases posteriorly and represents limited access for implant placement and abutment screw insertion.
Cheek biting is more common due to the proximity of the buccinator muscle.
The bone quality is inferior, with increased risk for bone loss or implant failure.
Increased mandibular flexure and torsion occur in this area during opening or heavy biting on one side.
Facial artery perforation during surgery can cause life-threatening bleeding.
Costs often do not warrant benefits.
The primary disadvantage is potential extrusion and loss of the maxillary second molar or loss of proper interproximal contact, with increased caries or periodontal risk.
If extrusion is a concern, a crown on the mandibular first molar may include an occlusal contact with the mesial marginal ridge of the maxillary second molar, or the maxillary second molar may be bonded to the maxillary first molar.
Maxillary second molars are usually replaced with an implant when opposing a natural tooth.
Mandibular second molars are usually replaced when the third molar is in function and will remain present.

Multiple Missing Teeth

No Treatment

Advantages

There are no inherent advantages beyond saving finances and time.

Disadvantages

Decreased Masticatory Function: Main disadvantage is decreased masticatory function, leading to more force and stress on remaining teeth.
Forces of mastication stress the remaining teeth, resulting in high chance of decay, mobility, periodontal issues, and tooth loss. Bone loss may occur.
Tooth Movement: Remaining teeth may continue to shift due to stresses, and teeth in the opposing arch will supraerupt due to lack of stimulation.
These phenomena complicate implant restoration.
Esthetics: Obvious esthetic issues will result.

Removable Partial Denture

See Box 22.2 for advantages and disadvantages.

Implant-Supported Multiple Crowns (Fixed Prosthesis)

Advantages

Ideal Prosthesis: Closest treatment to return edentulous patients to optimal form, function, and esthetics; feels like normal teeth psychologically.
Better than removable prosthesis; does not require removal and is less likely to impact food.
Less Bone Loss in Cantilevered Areas: Clinical studies show fixed restoration can reverse bone loss.
Decreased Maintenance: No attachments, so less maintenance is needed.

Disadvantages

Cost: Cost is usually higher, which may inhibit people from accepting treatment plan.
Esthetics: The esthetics may be inferior to a removable prosthesis. Because soft tissue support that supports facial appearance is not possible.
Food Impaction: Occurs when custom abutments are used to offset nonideal implant positioning.

Types of Prostheses

The primary methods used for retention of single or multiple implants are cement and screw retention.

Screw-Retained Restorations

Secured to the implant body directly or through a standardized abutment.

Advantages

Retrievability: Screw-retained restorations can be easily removed for complications such as prosthesis fracture or chipping.
For this reason, screw retention is often recommended for long-span, full-arch, and cantilevered restorations, or in cases where the prosthesis may require removal in the future.
Lack of Cement: Absence of the cement interface is another important advantage.
Excess cement at the margin has been shown to be an important iatrogenic contributing factor to implant complications, such as implant peri-mucositis and peri-implantitis.
If the soft tissue interface is part of the patient’s smile, then a screw-retained restoration is recommended.
Lack of Crown Height Space: Better retention for the prosthesis in areas where there is minimal interocclusal space.

Disadvantages

Esthetics Is Dependent on Implant Positioning: Esthetics of the prosthesis is highly dependent on the implant positioning in the x, y, and z axes.
Often access hole would be required to be in the buccal to obtain proper aesthetic.
Access Hole: The greatest disadvantage to screw-retained restorations involves the screw access hole in the restoration.
Without explanation, screw holes can be a cause of concern.
Difficulty in Obtaining a Passive Fit: Some authors have reported increased difficulty in obtaining a passive fit.

Cement-Retained Restorations

Consist of a conventional crown or bridge prosthesis cemented over one or more abutments.

Advantages

More Traditional Prosthetic Technique: Parallels traditional prosthetics, so many clinicians and staff are comfortable completing cement-retained prostheses.
Passive Fit: More passive fit is obtained where more passive in comparison with a screw-retained prosthesis.
Cement space is ideally approximately 40 μm and compensates for any fit variation. Therefore is more passive in comparison with screw retained.
Screw-retained prostheses exhibit some degree of nonpassiveness.
No Access Hole: The lack of a screw access hole in the restoration aids in aesthetics.

Disadvantages

Retrievability Difficulty: Retrievability Cement-retained res- torations are more difficult for the clinician to remove from the patient after delivery.
Preparation must be sufficiently retentive.
Requires Increased Crown-Height Space: A cement-retained restoration requires a minimum of 7 to 8 mm of CHS, whereas a screw- retained restoration can be successfully delivered with a space of 5 to 7 mm.
Cement Retention: Risk for excess retained cement and the peri-implant complications.

Miscellaneous Restorations

Angulated Screw Channel

ASC allows a screw-retained prosthesis to be fabricated when angulations of the implant are less than 25 degrees by using a lingual access to fixate the prosthesis.

Screw-Cementable (Combination) Prosthesis

Combines temporary cement advantages over the telescoped abutment (cement-retained) and fixation screws on the screw-retained part of the prosthesis.
Allows for retrievability, ease of seating, and enhanced esthetics.

Ideal Positioning for Screw and Cement-Retained Prosthesis

Anterior
Cement retained: slightly lingual to the incisal edge
Screw retained: cingulum area
Posterior
Cement retained: central fossa
Screw retained: central fossa

Abutment Options

Abutments for Cement-Retained Restorations

Standardized (Stock) Abutments

Prefabricated components that are screw retained and intended to be connected directly to the endosseous implant platform.
These abutments are used for the retention of a cemented prosthesis for single- or multiple-implant prostheses.
Standardized abutments are advantageous because they are inexpensive and often can be modified by the clinician or laboratory.
The disadvantages of these abutments are tissue transparency and poorer tissue health.

Custom Abutments

Fabricated by using a castable abutment or through a CAD/CAM process.
Can be designed with the margin in the ideal position with respect to the soft tissue drape around the implant.
Allow for better soft tissue health, along with correction of nonideal implant placement.

Abutments for Screw-Retained Restorations

With few exceptions, most abutments for screw-retained restorations are standardized components (e.g., multiunit abutments).
Multiunit abutments allow for prostheses design that mimic a natural emergence profile from the soft tissue now. By being connected to the implant platform directly.

Restorative Materials

The modern materials include, monolithic ceramics like zirconia and lithium disilicate, as well as porcelain fused to metal.

Zirconia

Compared with other all-ceramic crown and bridge materials, monolithic zirconia exhibits a unique combination of high flexural strength, fracture toughness, and exceptional esthetics.
Made to use in the posterior and anterior of mouth.

Lithium Disilicate and Lithium Silicate

**Lithium disilicate is a monolithic materials that highly versatile to use in restoration. Althought not providing the same flexural or fracture toughness shown by zirconia materials, the can exhibit higher levels of translucency. Can be used for veneer

Metal-Ceramic

Created stronger and more accurately to the patient.

Gold Alloy

Been used for long time, but has decline in popularity because of higher metal cost. More of the crown are made in gold alloy.

Polymethylmethacrylate

Is a stable resin, and is commonly used to create short and medium term provisional implact restorations