The "Hollywood Smile"
The "Hollywood Smile" is a media ideal dating back to the early 1900's. Teeth were in such disrepair that people would not smile for photographs. The only smiles seen were created in published media as cartoons. Artists depicted teeth as solid white areas with the upper and lower teeth separated by a curved line following the lower lip. The curved line created an image of the front teeth being the longest and every tooth gets shorter all the way to the corners of the mouth.
Today, the "Hollywood Smile" is an improved media ideal. The lips are filled with very white teeth that block out darkness in the back of the mouth. Incising edges of top teeth follow the line of the lower lip coming within a millimeter of contact. Two front teeth are most prominent with adjacent teeth appearing sequentially smaller from the front teeth to the corners of the mouth creating perspective. Ideally, each tooth looks one sixteenth smaller than the adjacent tooth in front of it. There is symmetry of tooth color, shape and position right side to left side of the midline.
A masculine smile has square teeth. Incising edges of top teeth follows a straighter line. A feminine smile has rounded teeth. Incising edges of top teeth follows the lower lip line closer creating more curvature.
The Natural Smile
Natural smiles are seen everyday. Teeth fill the space between the lips and block out darkness in the back of the mouth. They are shades that blend with skin tones. Incising edges of top teeth follow the line of the lower lip, however, the two lateral incisors adjacent to the front teeth are shorter. The eyeteeth appear longer. Two front teeth are most prominent with adjacent teeth appearing sequentially smaller from the front teeth to the corners of the mouth creating perspective. Ideally, each tooth looks one sixteenth smaller than the adjacent tooth in front of it. There is symmetry of tooth color, shape and position right side to left side of the midline, however variation creates a natural appearance. Development and aging of teeth alters these relationships.
Natural smiles often have rotated, tilted, crowded, or spaced teeth. There is wear of outer and biting surfaces, gum recession and root exposure, chips, cracks or cavities. The four front incisors are the same color, the eyeteeth darker and the bicuspids and molars slightly lighter. Each tooth has great color variation over its surface. Teeth have a relatively translucent enamel shell with yellow dentin under it. As enamel thins and shows through yellow dentin, the tooth looks more yellow as occurs in the third of the tooth closest to the gums. Areas where dentin is not behind enamel as occurs between teeth and along the biting edge, appear dark gray because the translucent enamel allows darkness of the back of the mouth to show through.
The back of the mouth is a dark space as no light enters. Incorrect tooth position, tooth loss, malformed teeth, and loss of tooth structure from trauma or cavities create spaces that show the darkness of the back of the mouth.
Perception esthetics recognizes that various smile designs and tooth defects are used to produce natural-looking smiles, and that a dentist's perception of a patient results in a final smile design that fits the individual. Defining patient esthetic values and appreciation levels is essential to patient satisfaction.Without proper assessment, final smile design becomes the artistic interpretation of the dentist, which may or may not be acceptable to the patient. A dentist who does not understand perception esthetics produces the same smile for every patient, within the bounds of physical or financial limitations. The perfect smile, based on the "Golden Rule" of esthetic dentistry can be ideal for a 20-year-old patient but not ideal for an older patient. Table 1 lists the types of imperfections that need to be evaluated to ensure patient satisfaction.
Restoration goals must be balanced with limitations of ideals and limitations of treatment. Limitations of ideals include general traits (cultural, physical, and personality limitations), detailed inspection, and visual perception. Limitations of treatment include patient and dentist limitations. Patient limitations include physical, psychological, and financial limitations. Dentist limitations include artistic, perceptive, and technical ability (ie, material and laboratory limitations). "
Tooth and Smile Defects
Tooth defects that affect smile esthetics include color, shape and position. Correctionsof unacceptable defects improve smiles. Inclusion of acceptable defects creates a natural smile. Aesthetics is an art and consequently, beauty is a personal preference and defining a patient's preferences is critical.
Treatment goals must be realistic based on limitations of ideals and limitations of treatment. Perception Aesthetics is a concept I published in the Journal of Esthetic Dentistry in the 1990's. Perception Aesthetics review all factors that define realistic expectations for treatment goals.
Aesthetic recontouring is the process of selectively remodeling teeth to affect their shape, position, length, and contours. Youthful, feminine smiles are typically characterized by rounded edges. In a more masculine smile or one characteristic of an older individual, flat worn surfaces are more prominent. Significant generalized changes are possible when treating front teeth visible in the patient's smile. Ideally, recontouring is confined to enamel and results in teeth of proper proportion. Significant changes are possible when treating front teeth visible in the patient's smile.
Bleaching lightens teeth by removing stain caught in microscopic holes within enamel. The active ingredient in most of the whitening agents iscarbamide peroxide, also known as urea peroxide; when water contacts this white crystal, the release of hydrogen peroxide lightens the teeth. Bleaching is successful in at least 90 percent of patients, though it may not be an option for everyone. Consider tooth bleaching if your teeth are darkened from age, coffee, tea or smoking. Teeth darkened with the color of yellow, brown or orange respond better to lightening. Other types of gray stains caused by fluorosis, smoking or tetracycline are lightened, but results are not as dramatic. Every case is different. Typically, there is a multiple-shade improvement as seen on a dentist's shade guide. If you have very sensitive teeth, or teeth with worn enamel, your dentist may discourage bleaching. Existing restorations such as crowns and fillings do not change color.
The dentist or hygienist will make impressions of your teeth to fabricate a bleaching appliance for you. The appliance is custom made for your mouth. Along with the appliance, you'll receive the bleaching materials and you'll be given instructions on how to wear the appliance. Some bleaching systems recommend bleaching your teeth from one to four hours a day. Generally this type of system requires three to six weeks to complete. Other systems recommend bleaching at night while you sleep. This type of system usually requires only 10-14 days to complete.
Lightness should last from one to five years, depending on your personal habits such as smoking and drinking coffee and tea. At this point you may choose to get a touch up. This procedure may not be as costly because you can probably still use the same appliance.
The retreatment time also is much shorter than the original treatment time. Several studies, during the past ten years, have proven bleaching to be safe and effective. The American Dental Association has granted its seal of approval to some tooth bleaching products. Some patients may experience slight gum irritation or tooth sensitivity, which will resolve when the treatment ends.
Composite Fillings – Front Teeth
A composite resin is a tooth-colored plastic mixture filled with glass. Composites are not only used to restore decayed areas, but are also used for cosmetic improvements of the smile by changing the color of the teeth or reshaping disfigured teeth.
In order to bond a filling material to your tooth, it is first necessary to remove decay, prepare the tooth and then to condition the enamel and dentin. Once conditioned, a thin resin is applied which bonds to the etched surface. The bond strength of these fillings is incredible.
Following preparation, the dentist places the composite in layers, using a light specialized to harden each layer. When the process is finished, the dentist will shape the composite to fit the tooth. The dentist then polishes the composite to prevent staining and early wear. Bonding increases the strength of these restorations far beyond those of only a short time ago.
Composites bond to the tooth to support the remaining tooth structure, which helps to prevent breakage and insulate the tooth from excessive temperature changes. After receiving a composite, a patient may experience post-operative sensitivity.Also, the shade of the composite can change slightly if the patient drinks tea, coffee or other staining foods. The dentist can put a clear plastic coating over the composite to prevent the color from changing if a patient is particularly concerned about tooth color.
Composites tend to wear out in larger cavities, although they hold up well in small cavities. After placement, you may chew right away. The light instantly hardens these fillings. Your teeth may experience some degree of temperature sensitivity for a few days to a week. If it does not disappear within that period of time, contact your dentist.
These light cured composites are extremely cosmetic and most often bonded into place in one appointment. They are often referred to as "bonding." Studies have shown that composites last 7-10 years.
In the past, teeth were most commonly repaired with silicate or acrylic restorations. Thanks to advances in modern dental materials and techniques, teeth can be restored with a more aesthetic and natural appearance. There are different types of cosmetic fillings currently available. The type used will depend on the location of the tooth and the amount of tooth structure that needs to be repaired.
White Composites – Back Teeth
A composite resin is a tooth-colored plastic mixture filled with glass. In the past, dental composites were confined to the front teeth because they were not strong enough to withstand the pressure and wear generated by the back teeth.
Following preparation, the dentist places the composite in layers, using a light specialized to harden each layer. When the process is finished, the dentist will shape the composite to fit the tooth. The dentist then polishes the composite to prevent staining and early wear. It takes the dentist about 10-20 minutes longer to place a composite than a silver filling. Placement time depends on the size and location of the cavity and the larger the size, the longer it will take.
The average cost of posterior composites is about one-and-a-half to two times the price of a silver filling. Most dental insurance plans cover the cost of the composite up to the price of a silver filling, with the patient paying the difference. As composites continue to improve, insurance companies are more likely to increase their coverage of composites.
Esthetics are one of the main advantages, since dentists can blend shades to create a color nearly identical to that of the actual tooth. Composites bond to the tooth to support the remaining tooth structure, which helps to prevent breakage, minimize leakage and insulate the tooth from excessive temperature changes.
After receiving a composite, a patient may experience post-operative sensitivity. Also, the shade of the composite can change slightly if the patient drinks tea, coffee or other staining foods. Composites tend to wear out sooner than silver fillings in larger cavities, although they hold up as well in small cavities. Studies have shown that composites last 7-10 years, which is comparable to silver fillings except in very large restorations, where silver fillings last longer than composites.
In the past, teeth were most commonly repaired with amalgam (silver) fillings or gold restorations. Thanks to advances in modern dental materials and techniques, teeth can be restored with a more aesthetic and natural appearance. There are different types of cosmetic fillings currently available. The type used will depend on the location of the tooth and the amount of tooth structure that needs to be repaired.
The other type of "white fillings" are called Composite or Porcelain Inlays and Onlays. These fillings are usually placed in back teeth when esthetics is of utmost concern. In order to increase their strength and longevity, they are fabricated in the laboratory and then bonded into position in the office. This is a two visit procedure rather than the one visit required to place a direct composite filling. However, when it comes to strength and cosmetics, the extra time and expense is well worth it! I hope that you now understand a little bit more about white fillings.
Porcelain veneers are thin shells of ceramic material, which are bonded to the front of teeth. They can be the ideal choice for improving the appearance of the front teeth. Porcelain veneers are placed to mask discolorations, to close spaces, to brighten teeth, to straighten teeth, and to repair broken tooth structure. Highly resistant to permanent staining from coffee, tea, or even cigarette smoking, the wafer-thin porcelain veneers can achieve a tenacious bond to the tooth, resulting in an esthetically pleasing naturalness that is unsurpassed by other restorative options.
Porcelain veneers are an excellent alternative to crowns or fillings in many situations. They provide a conservative approach to changing a tooth's color, size, shape or position. Porcelain veneers can mask undesirable defects, such as teeth stained by tetracycline, by an injury, or as a result of a root canal procedure, and are ideal for masking discolored fillings in front teeth. Patients with gaps between their front teeth or teeth that are chipped or worn may consider porcelain veneers. Generally, veneers will last for many years, and the technique has shown remarkable longevity when properly performed.
Patients may need several appointments for the entire procedure including diagnosis and treatment planning, preparation, and bonding. It's critical that you take an active role in the smile design. Spend time in the decision-making and planning of the smile. Understand the corrective limitations of the procedure to correct tooth defects, color or position.
The preparation appointment will take from one to several hours. To prepare the teeth for the porcelain veneers, the teeth are lightly reduced to allow for the small added thickness of the veneer. Usually, about a half a millimeter of the tooth is removed, which may require a local anesthetic. At this appointment, a mold is taken of the teeth, which is sent to the laboratory for the fabrication of the veneers. This can take about one to three weeks. If the teeth are too unsightly a temporary veneer can be placed, at an additional cost.
Bonding of veneers will take about one or two hours. First, the dentist places the veneers with water or glycerine on the teeth to check their fit and get a sense of the shade or color.While the veneers are resting on your teeth, view the esthetic results, and pay particular attention to the color. At this point, the color of the veneers can still be adjusted with the shade of the cement to be used. The color cannot be altered after veneers are cemented. To apply the veneer, the tooth is cleansed with specific chemicals to achieve a bond. Once a special cement is sandwiched between the veneer and tooth, a visible light beam initiates the release of a catalyst to harden the cement.
All porcelain restorations are called veneers when they cover only the front of teeth. They are crowns when they cover all surfaces of teeth. Restorations are three quarter crowns when they do not cover the surface of teeth toward the tongue. It is often difficult to distinguish one type of restoration from another and therefore, it is easier to call them bonded porcelain restorations.
Crowns – Front and Back Teeth
Crowns are used to support a tooth when there isn't enough of the tooth remaining, protect weak teeth from fracturing, restore fractured teeth, or cover badly shaped or discolored teeth. A crown is a restoration that covers a tooth like a thimble to restore it to its normal shape and size while improving strength and appearance of a tooth. Crowns are necessary when a tooth is generally broken down and fillings won't solve the problem. If a tooth is cracked, a crown holds the tooth together to seal the cracks so the damage doesn't get worse.
To prepare the tooth for a crown, it is reduced so the crown can fit over it. An impression of teeth and gums is made and sent to the lab for the crown fabrication. A temporary crown is fitted over the tooth until the permanent crown is made. On the next visit, the dentist removes the temporary crown and cements the permanent crown onto the tooth.
Crowns require more tooth structure removal, hence, they cover more of the tooth than veneers. Crowns are customarily indicated for teeth that have sustained significant loss of structure. Crowns are made from various materials including plastics, porcelains and metals or combinations of these.
The dentist's main goal is to create crowns that look like natural teeth. To achieve a certain look, a number of factors are considered, such as the color, bite, shape, and length of your natural teeth. When the procedure is complete, your teeth will not only be stronger, but they may be more attractive.
Crowns should last approximately 12 years. However, with good oral hygiene and supervision most crowns will last for a much longer period of time. Some damaging habits like grinding your teeth, chewing ice, or fingernail biting may cause this period of time to decrease significantly.
To prevent damaging or fracturing the crowns, avoid chewing hard foods, ice or other hard objects. You also want to avoid teeth grinding. Besides visiting your dentist and brushing twice a day, cleaning between your teeth is vital with crowns. Floss is important to remove plaque from the crown area where the gum meets the tooth. Plaque in that area can cause dental decay and gum disease.
Replacing Missing Teeth
Fixed Bridges and Implants
A fixed bridge replaces missing teeth. Teeth on either side of the space are prepared for crowns. Crowns are joined together so crowns on either side can support the missing teeth in the middle.
Implants, usually made of titanium metal similar to that used in pins to join fractured bones, are permanent replacements for missing teeth. Part of the implant acts as the root of a tooth and supports a section that extends above the gums. Replacement teeth may be permanently fixed to the sections above the gums, like fixed bridges, or can be removable similar to overdentures.
Partial dentures replace missing teeth supported by gums and remaining teeth. Removable partial dentures usually consist of replacement teeth attached to pink or gum-colored resin bases, which are connected by a metal framework. Removable partial dentures attach to your natural teeth with rests, guide planes and metal clasps. The metal clasps often shows when smiling. A denture helps you to properly chew food, improve speech and prevent a sagging face by providing support for lips and cheeks.A full denture is held in by suction so function is compromised.
An overdenture is a denture that uses precision dental attachments to hold the denture down. The overdenture attachment can be placed in tooth roots that have been saved, or placed onto dental implants that have been placed to receive them. When proper smile design principals are applied to dentures, they can look very natural. Indeed, most denture patients want more imperfections in their denture teeth so they look more natural.
There is a substantial difference between full dentures and your own teeth since it is only suction which holds a full denture in place.
Dentures may move or come loose when the tongue, lips, cheeks and muscles push against it. Good impressions provide an accurate fit and seal around the edges. Retention and stabilization can be aided by the shape of bone and firmness of gums which make it more difficult to break the suction.
It is difficult to predict how a patient will adapt to dentures.A stable, retentive denture increases success, but people must adapt psychologically and learn techniques of functioning with a denture. Speech patterns must be relearned and chewing efficiency may be dramatically reduced. For these reasons, full dentures are the last resort of dentistry.
There are two alternatives to full dentures: overdentures and implants. Occasionally weak teeth can be used to stabilize dentures. Teeth reduced in height are much stronger because forces are closer to the gums reducing the force generated on their roots.
Overdentures are dentures which fit over weak teeth reduced in height after root canals. In addition, precision attachments can be placed in these teeth and dentures for added retention. Retaining roots will also help maintain bone height which might recede if roots were not there.
Source by Paul Chalifoux