Dear Doctor,
I was intrigued to learn that implant crowns can either be screwed into implants or cemented on to them. Wouldn’t a screwed-in crown look awful? Why would I want to have my crown attached this way?

Once a crown is attached to the implant, a person cannot determine which method of attachment was used (from the frontal view).

Dear Jake,
I can understand your concerns; after all, you want your replacement tooth to function well, and look perfectly natural. Rest assured, you can have both with either a “screwed-in” or “cemented” implant crown.

While implants replace teeth, they are artificial and behave differently from natural teeth. A quick recap will be helpful in explaining why. A dental implant is a tooth-root replacement, to which an implant crown is attached. The crown is the only part you see in the mouth. The implant is placed surgically in the bone of the jaw to which it fuses in a process called osseo-integration (“osseo” – bone; “integrate” – to join or fuse). A great deal of thought, research and ingenuity has gone into dental implant tooth-replacement systems to make them as fail-safe as possible. Over and above what you see, there are many other clinical aspects and considerations involved in their design and functionality to protect and maintain implant survival.

Cemented Crown vs. Screw-Retained Crown Click to enlarge

Dental Implants — Dental Legos

Screws facilitate the attachment of the implant crowns to the implants. Implants must be strategically placed to allow implant crowns to connect to them, so that the crowns emerge through the gum tissues in exactly the right direction. An adjoining support structure called an “abutment” is often used to allow for this transition and connection.

Like Legos, implant components are designed to disassemble. Screw-retained implant crowns are more easily maintained; they allow forretention — keeping abutments and implant crowns in place, and retrievability — allowing the implant-crown components to be more easily removed, repaired or replaced, without damaging the implant or the restoration. While a successful dental implant can last a lifetime, most crowns do not. They may need to be replaced or repaired periodically, and this is much easier to do if they are attached with screws.

Loosening of the screw that attaches the restoration to the implant occasionally happens. Retightening or replacing the screw when the restoration is screw-retained is a simple and predictable procedure. This cannot be said for cemented restorations. Cemented crowns can be difficult to remove and, in the worst case, a screw access hole may have to be put in to remove the abutment and crown from the implant. Creating a screw access hole in the back teeth is not a cosmetic problem but for the front teeth, creating the screw access hole may affect the crown’s appearance. It is difficult to know where the screw exit is located and often crowns removed in this fashion have to be remade. A weaker cement can be used to facilitate removal but this can lead to an insecurely attached crown falling off the abutment during use.

Aesthetic Considerations

People can object to screw-retained crowns believing that they may be unsightly — and in places, that might be true. That’s why implant crowns are cemented to abutments whenever screws would show. Cemented restorations can accommodate more implant positions by covering abutment screw holes completely.

Screw-retained restorations can only be used in areas where the screw access holes are not so conspicuous, like the biting surfaces of back teeth. These access holes can be filled with composite tooth-colored filling material, rendering them essentially invisible to all but the dentist.

Keep in mind that cementation, too, can be problematic: Removal of excess cement, particularly if the implant-to-crown connection is deep within the tissues, can be difficult.

Screws Are Safer In Certain Situations

Immediately Loaded Implants
Screw-retained crowns are easier to manage when implants are crowned immediately. An implant is usually left in place for several months to fuse to the bone (osseo-integrate) before a crown is attached. But in some cases, the crown will be attached at the same time that the implant is placed — a process referred to as “immediate loading.” Here, screws offer additional advantages over cement. Sometimes the cement seal can be lost during the critical six-to-eight-week initial healing period or the cement can cause inflammation if it flows below the gum tissues.

Provisional Implant Crowns
To develop ideal aesthetics, a provisional (customized temporary) crown is required to shape and mold the soft gum tissues. The simplest method is to use a screw-retained provisional restoration. The screw can actually be used to “seat” the provisional crown and gently expand and accommodate the gum tissues.

Long-Term Treatment Planning
This topic is an extension of retrievability. Given the long-term survival characteristics of today’s dental implants, they can outlast neighboring natural teeth that ultimately succumb to decay or periodontal disease. In these situations, the implants can often be used to support bridges if more natural teeth are lost. Sometimes even the substructures (the implants and abutments) of the existing implant crowns can be incorporated into the new bridgework. Screws play an important role in being able to retrieve and re-use existing implant restorations.

So as you can see, screwed-in crowns and cements have advantages and disadvantages. Your dentist will recommend which option is best for you.

Many children that don’t wear protective mouthguards while playing sports should be doing so, according to a survey conducted by Delta Dental Plans Association. These findings indicate that children aren’t listening to their dentists.

Delta Dental recently did a wide-ranging survey regarding the oral health of American children.

Aside from the obvious protection provided to the teeth, mouthguards absorb shock and soften a blow that could have resulted in a concussion. The US Centers for Disease Control and Prevention calculated that around 300,000 people suffer sports-related concussions every year—children and teenagers are at the highest risk.

About seven of 10 parents reported that their child doesn’t wear a mouthguard for sports like baseball, basketball, soccer or softball. Parents of athletes in these sports are less fearful of injury than if their child played hockey, lacrosse or football, for example. Studies, however, indicate that basketball players are 15 times more likely to experience an orofacial injury than a football player is.

Since mouthguards became mandatory for football players, mouth injuries have declined significantly. Still, only about 70 percent of parents claimed their child always wears a mouthguard during practices and games. Around 44 percent of hockey parents said their child wore a mouthguard for games and practices.

The three kinds of mouthguards available include: (1) stock mouthguards, which are the least expensive; (2) mouth-formed mouthguards, which can be purchased at sporting goods stores and can conform to the child’s mouth; and (3) custom-made mouthguards, the most expensive choice, which are made from a dentist and are molded to the child’s teeth.

Regardless of how much money a parent wants to pour into mouth protection, any mouthguard is better than nothing.

What was nearly impossible just a short time ago, Dr. Gardner now makes happen hundreds of times each year! You can receive beautiful new teeth, in just one day!

Advances in implant technology and new protocols developed by experienced Doctors allow for less invasive surgery without bone grafts that results in the ability to replace failing or missing teeth with customized, hand-crafted replacements immediately or soon thereafter.

This can be done with ONE tooth or MULTIPLE teeth and eliminates the need for a removable temporary appliance while maintaining near normal function during the healing phase. Since the teeth are fixed to implants, there is usually a shorter adjustment period.

Not everyone is a candidate for this procedure. A clinical exam is necessary to determine the right conditions. Teeth delivered at the time of surgery are provisional (temporary) teeth, and will be changed to a final prosthesis after complete healing. The provisional teeth can be used for as long as a year. This process is called Immediate Loading and is carried out in a predictable fashion as long as patients meet the necessary criteria. Immediate Loading is a procedure I enjoy most and consider it to be one of the many modern miracles in Dentistry. 

Same day dentistry refers to an innovative new brand of treatment that condenses some traditional procedures into a single office visit. Thanks to in-office dental CAD/CAM technology, patients can receive milled metal-free crowns, veneers, onlays and inlays in one office visit, while they wait. If your dentist uses a CEREC or E4D Dentist System in the dental office, same day dentistry may be a treatment option for you.

The Technologies Behind Same Day Dentistry

CEREC: The CEREC in-office dental CAD/CAM equipment by Sirona includes a digital infrared camera for obtaining an optical impression of the damaged tooth, 3-D CAD software for designing the restoration, and CAM technology (milling unit) that uses high-speed burs to mill the restoration.

E4D Dentist System: Developed and manufactured by D4D Technologies, the E4D Dentist System uses laser scanning technology to capture the optical impression of tooth preparations. In most instances using the laser eliminates the need for the reflective powder agents required for some digital impression or CAD/CAM systems. The E4D Dentist System also includes 3-D CAD software for designing the restoration, as well as CAM technology (milling unit) that uses burs to mill the restoration.

Same Day Dentistry Procedure

After your dentist has examined your teeth and determined a same day CAD/CAM restoration is a treatment option, the area surrounding the affected tooth or teeth will be anesthetized and prepared for your metal-free restoration.

A digital impression is taken using an optical or laser scanner and entered into a computerized system. This system is used to create a virtual model of your teeth and design your crown, veneer, inlay or onlay. This process involves identifying the appropriate color, shape and biting/chewing surface for your restoration.

The design then is sent via cable or wirelessly to a milling unit in the dentist’s office that will fabricate the restoration in approximately 20 minutes. The metal-free materials used for CAD/CAM restorations include blocks of porcelain, composite and lithium disilicate.

The mill uses burs to cut the block to the precise shape of your specific restoration. When the milling process is complete, the restoration can be polished or stained and glazed to create a life-like appearance that will match and blend with your natural teeth. If stain and glaze are used (which can take anywhere from 15 to 20 minutes, depending on what’s required), the restoration will be fired in an oven (similar to pottery) for approximately 15 minutes or less. The total process may take as little as 60 to 90 minutes.

Once the restoration is finished and inspected, it is placed and checked for fit, then cemented. The result is a permanent treatment completed in a single office visit.

Same Day Dentistry Recovery and Follow-up Care

After your veneer, crown, inlay or onlay has been placed, your dentist will provide information about caring for your new restoration. In general, maintain proper oral hygiene habits by brushing twice daily and flossing with dental floss or interdental cleaners (specially designed brushes and sticks) once a day to remove plaque and help prevent dental decay and gum disease.

Avoid chewing hard foods, ice or other hard objects, since these could damage your restorations. It also is important to avoid biting your fingernails and grinding your teeth, which could significantly shorten the life-span of your restoration. If you clench or grind your teeth, your dentist may recommend wearing a night-time mouth guard to help protect your restorations while sleeping.

Benefits of Same Day Dentistry

With in-office CAD/CAM dentistry, multiple appointments for the same treatment are no longer necessary, which saves time. Instead, needed restorations are identified, created and cemented in the same day when appropriate.

Additionally, you may only need to receive local anesthetic once for any necessary tooth preparations, the effects of which can be minimized with an anesthetic reversal agent like OraVerse.

Because in-office CAD/CAM restorations usually are designed based on digital impressions obtained with optical scanning technology, traditional impression materials and trays are not used to duplicate tooth form and anatomy. As a result, there is no need for the traditional, distasteful materials previously used for impressions and therefore less likelihood of discomfort or gagging.

Same day CAD/CAM dentistry also eliminates the need for temporaries, since the permanent and clinically proven final restorations are placed in one visit. This reduces concerns about tooth sensitivities that could otherwise result when wearing temporary restorations, or about the temporaries falling out at inconvenient times.

Cost of Same Day CEREC or E4D Dentistry

All-ceramic restorations, including those fabricated using CAD/CAM technology, tend to be a more expensive restorative option. However, even though the materials for CAD/CAM restorations might cost more, the expense incurred by the dental laboratory and/or the dentist may not be passed onto the patient. Also, there is no additional fee or cost to have a restoration placed in one visit as opposed to two.

Therefore, costs for CEREC or E4D same day dentistry will depend on the normal and customary fees charged by dentists in your area, the extent of treatment required and your dental insurance. Insurance reimbursement for in-office, same day dentistry is similar to reimbursement for restorations created by a laboratory.

It should be noted that the initial very high cost of the equipment to the dentist may affect the cost of the restoration for the patient.

Dr. Gardner was featured in the Spring/Summer 2011 edition of Glow magazine!

Please click the link below to view the full article.

Glow Magazine (PDF Format)

Dental Implant Procedure: Advantages and Success Rate

Although you have a number of restorative options for the treatment of missing teeth, none have proven to be as functionally effective and durable as implants. In many cases, dental implants may be the only logical choice for the restoration of all necessary functionality of the teeth and supporting structures. Dental implants are artificial tooth replacements used to counter tooth loss. The procedure is categorized as a form of prosthetic (artificial replacement) dentistry, though it also falls into the category of cosmetic dentistry as well.
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