Porcelain Fused to High Noble Metal (PFM)
Dental crowns: also referred to as “dental caps,” “tooth crowns,” or “tooth caps,” crowns are fixed prosthetic devices that are cemented onto existing teeth or implants by a dentist or prosthodontist. In addition to strengthening a damaged tooth, crowns can be used to improve a tooth’s appearance, shape, alignment and dental occlusion (bite). Gaps left by missing teeth can cause the remaining teeth to shift, which can result in a bad bite. Crowns help prevent this from happening. Crowns cover most of the exposed portion of your tooth and decay does not affect a crown since it is made of metal and /or porcelain. However, where the natural tooth meets the crown can become decayed.
Process – the procedure for installing a dental crown normally takes two separate dentist visits.
At your first appointment, our dentist will examine the tooth to make sure that it can support a crown, then begin filing it down to prepare for the crown. Alternatively, if the tooth is severely damaged or broken, our dentist may need to fill it in to make it large enough to properly receive the crown.
After the tooth is filed or filled to the proper shape, our practitioner will take an impression of the tooth, as well as those surrounding it, and send it away to our dental lab, so the permanent crown can be made accordingly. By the end of this first visit, your tooth will have a new temporary crown that protects it until the final crown is ready to be permanently placed.
When the permanent crown is ready, you will have your second visit. At this appointment, the temporary crown is removed, after which our dentist will position and fasten the new crown to the tooth with a special adhesive.
At amazing dental care, we schedule next day appointments for patients who provide their own transportation and remain in the yuma area overnight. For those patients who rely on our transportation from the valley, we normally schedule non-consecutive days of travel. We have found that this approach significantly reduces the length of day for our drivers, making the entire operation much safer for everyone involved.
Pfm bridges and crowns can be thought of as a hybrid as they are made from both all -metal and all-ceramic materials. A metal alloy is used to create a thin thimble-like “cap” that fits snugly over the tooth. Porcelain is then fused over the substructure to form the shape of the unit or crown and give it a white tooth-like appearance. Porcelain-fused-to-metal restorations have a 50+ year track record of providing lasting and durable service.
Advantages of pfm
with the pfm having a metal base, it is the ideal crown for molars.
Due to differences in how they’re made, a pfm’s metal substructure typically achieves a more exacting fit over its tooth than an all-ceramic one.
Even if some of its surface layer of porcelain fractures off, the metal substructure underneath will characteristically stay intact thus maintaining the crown’s seal over, and reinforcement of, the tooth. In comparison, the full thickness of an all-ceramic may fracture, thus compromising both functions.
Disadvantages of pfm
the issue of appearance is a difficulty with pfm’s. In situations where appearance is critical (like with incisors or eyeteeth, and especially in cases where just one or a few crowns are being placed), opting for an all-ceramic might make the better-matching choice.
Over time, a pfm crown can wear at the gum line and display a thin gray line. While this does not weaken the crown, it can be of concern to some.
For posterior teeth that show (like premolars and 1st molars) the added strength that a pfm offers might make its possibly just-average appearance an acceptable tradeoff.
Pfms require a greater amount of tooth reduction (trimming) than their all-metal and zirconia counterparts.
A pfm crown can be a little “bulkier” than a cosmetic porcelain or zirconium crown.
Some people are allergic to the metals used.
Corrosion is sometimes a concern with these materials.
Adjustment period: it is okay for the crown to feel a little out of place for a few days after cementing. This is because the teeth around this area are adjusting to new forces both in between the teeth and upon biting.
Preventive procedures: to provide optimum longevity for your restorations and to prevent future decay and supporting-tissue breakdown, please use the following home care tips:
Brush after eating and before bedtime around the crown with a soft toothbrush, especially where the crown meets the gum line. At this gum line harmful bacteria can be harbored to cause decay and gum disease. An electric toothbrush is highly recommended over manual to help you keep this area clean.
If you do not control the buildup of food debris and plaque your teeth and gums can become infected.
Water pik™ can be used with an antibacterial, alcohol free mouthwash like prescribed mouthwash at the gum line to keep this area healthy
Chewing: do not chew hard foods on the restorations for 24 hours from the time they were cemented—to attain optimum strength, the cement must mature for approximately 24 hours also avoid eating or chewing on hard objects, hard food, nails, hard candy or ice.
Avoid sticky treats like: caramels, taffy, gummy bears, caramels, salt water taffy, swedish fish, jelly beans, hard gum and other sticky candy.
Limit snacks, if high in sugar brush this area or swish with water
Remember tobacco, coffee, blueberries and tea may stain the crown
Sensitivity: do not worry about mild sensitivity to hot or cold foods. This sensitivity will disappear gradually over a few weeks. Infrequently, sensitivity last longer than six weeks.
Problems – call us if any one of these conditions occurs:
If the tooth is the first tooth to hit when you bite down after a couple of days, contact us for an adjustment.
If you experience a feeling of movement or looseness in the restoration.
If the crown becomes sensitivity to sweet foods or it develops a peculiar taste from the restoration site.
If you experience breakage of a piece of material from the restoration or sensitivity to pressure.
If a crowned tooth develops the need for a root canal procedure after a crown restoration