Maintaining a Healthy Smile and Different Treatments

Maintaining a Healthy Smile and Different Treatments:

FLUORIDE TREATMENT:

Fluoride therapy is the delivery of fluoride to the teeth topically or systemically in order to prevent tooth decay (dental caries) which results in cavities. Most commonly, fluoride is applied topically to the teeth using gels, varnishes, toothpaste/dentifrices or mouth rinse. Systemic delivery involves fluoride supplementation using water, salt, tablets or drops which are swallowed. Tablets or drops are rarely used where public water supplies are fluoridated.

ORAL PROPHYLAXIS:

Oral hygiene is the practice of keeping the mouth and teeth clean to prevent dental problems, most commonly, dental cavities, gingivitis, and bad breath. There are also oral pathologic conditions in which good oral hygiene is required for healing and regeneration of the oral tissues. These conditions included gingivitis, periodontitis, and dental trauma,  such as subluxation, oral cysts,  and following wisdom tooth extraction.

Cleaning of teeth

Teeth cleaning is the removal of dental plaque and tartar from teeth to prevent cavities, gingivitis, and gum disease. Severe gum disease causes at least one-third of adult tooth loss.

Tooth decay is the most common global disease. Over 80% of cavities occur inside pits and fissures on chewing surfaces where brushing cannot reach food left trapped after every meal or snack, and saliva or fluoride have no access to neutralise acid and remineralise demineralised teeth, unlike easy-to-reach surfaces, where fewer cavities occur.

Dental sealants, which are applied by dentists, cover and protect fissures and grooves in the chewing surfaces of back teeth, preventing food from becoming trapped thus halting the decaying process. An elastomer strip has been shown to force sealant deeper inside opposing chewing surfaces and can also force fluoride toothpaste inside chewing surfaces to aid in remineralising, demineralised teeth.

Since before recorded history, a variety of oral hygiene measures have been used for teeth cleaning. This has been verified by various excavations done throughout the world, in which chew sticks, tree twigs, bird feathers, animal bones and porcupine quills were recovered. Many people used different forms of teeth cleaning tools. Indian medicine (Ayurveda) has used the neem tree, or daatun, and its products to create teeth cleaning twigs and similar products; a person chews one end of the neem twig until it somewhat resembles the bristles of a toothbrush, and then uses it to brush the teeth. In the Muslim world, the miswak, or siwak, made from a twig or root, has antiseptic properties and has been widely used since the Islamic Golden Age. Rubbing baking soda or chalk against the teeth was also common.

Generally, dentists recommend that teeth be cleaned professionally at least twice per year. Professional cleaning includes tooth scaling, tooth polishing, and, if tartar has accumulated, debridement; this is usually followed by a fluoride treatment. However, the American Dental Hygienists' Association (ADHA) publicly stated in 1998 that there is an absence of evidence that scaling and polishing provides therapeutic value. The Cochrane Oral Health Group reviewed nine studies but found them to be of insufficient quality and not enough evidence to support the claims of the benefits of regular tooth scaling or tooth polishing.

Between cleanings by a dental hygienist, good oral hygiene is essential for preventing tartar build-up which causes the problems mentioned above. This is done through careful, frequent brushing with a toothbrush, combined with the use of dental floss to prevent accumulation of plaque on the teeth.

Removing plaque

Plaque is a yellow sticky film that forms on the teeth and gums and can be seen at gum margins of teeth with a food dye. The bacteria in plaque convert carbohydrates in food (such as sugar) into acid that demineralises teeth, eventually causing cavities. Daily brushing and flossing removes plaque and can prevent tartar from forming on the teeth.

Plaque can also cause gum irritation (gingivitis), making them red, tender and cause them to bleed. In some cases, the gums pull away from the teeth (receding gums), leaving cavities inhabited by bacteria and pus. If this is not treated, bones around the teeth can be destroyed. Teeth may become loose or have to be removed due to periodontal (gum) disease, mostly in adults. Eating a balanced diet and limiting snacks can prevent tooth decay and periodontal diseases. The Fédération dentaire internationale (FDI World Dental Federation) has promoted foods such as raw vegetables, plain yogurt, cheese, or fruit as dentally beneficial—this has been echoed by the American Dental Association (ADA).

Flossing

The use of dental floss is an important element of oral hygiene, since it removes plaque and decaying food remaining stuck between the teeth. This food decay and plaque cause irritation to the gums, allowing the gum tissue to bleed more easily. Acidic foods left on the teeth can also demineralise teeth, eventually causing cavities.

Flossing for a proper inter-dental cleaning is recommended at least once per day, preferably before brushing so fluoride toothpaste has better access between teeth to help remineralise teeth,  prevent  receding gums, gum disease, and cavities on the surfaces between the teeth.

It is recommended to use enough floss to enable easy use, usually ten or more inches with three to four inches of taut floss to put between teeth. Floss is then wrapped around the middle finger and/or index finger, and supported with the thumb on each hand. It is then held tightly to make taut, and then gently moved up and down between each tooth. It is important to floss under visible areas by curving the floss around each tooth instead of moving up and down on gums, which are much more sensitive than teeth. However, bleeding gums are normal upon first usage of floss, and will harden with use. One should use an unused section of the floss when moving around different teeth. Removing floss from between teeth requires using the same back-and-forth motion as flossing, but gently bringing the floss up and out of gaps between teeth.

Interdental brushes

An interdental brush, also called an interproximal brush or a proxy brush, is a small brush, typically disposable, either supplied with a reusable angled plastic handle or an integral handle, used for cleaning between teeth and between the wire of dental braces and the teeth. Brushes are available in a range of widths, color coded as per ISO 16409. Interdental brushes are classified according to ISO standard 16409:2006. The ISO brush sizes range from 1 to 7. The ISO brush size is determined by the PHD or Passage Hole Diameter in mm. This PHD is the minimum diameter of a hole that the interdental brush will pass through without deforming the brush wire stem. A peer-reviewed clinical study has found that using a toothbrush and an interdental brush more effectively removes plaque than using a toothbrush and dental floss.

Tongue cleaning

Cleaning the tongue as part of daily oral hygiene is essential, since it removes the white/yellow bad-breath-generating coating of bacteria, decaying food particles, fungi (such as Candida), and dead cells from the dorsal area of the tongue. Tongue cleaning also removes some of the bacteria species which generate tooth decay and gum problems.

Gum care

Massaging the gums with toothbrush bristles is generally recommended for good oral health.

Oral irrigation

Some dental professionals recommend oral irrigation as a way to clean teeth and gums.

Oral irrigators reach 3–4 mm under the gum line. Oral irrigators use a pressured, directed stream of water to disrupt plaque and bacteria.

COMPOSITE RESTORATIONS:

Advantages

The main advantage of a direct dental composite over traditional materials such as amalgam is improved aesthetics. Composites can be made in a wide range of tooth colors allowing near invisible restoration of teeth. Composites are glued into teeth and this strengthens the tooth's structure. The discovery of acid etching (producing enamel irregularities ranging from 5-30 micrometers in depth) of teeth to allow a micromechanical bond to the tooth allows good adhesion of the restoration to the tooth. This means that unlike silver filling there is no need for the dentist to create retentive features destroying healthy tooth. The acid-etch adhesion prevents micro leakage; however, all white fillings will eventually leak slightly. Very high bond strengths to tooth structure, both enamel and dentin, can be achieved with the current generation of dentin bonding agents.

Disadvantages

Clinical survival of composite restorations placed in posterior teeth has been shown to be significantly lower than amalgam restorations.  However, improvements in composite technology and techniques have improved their longevity.

Direct dental composites

A hand-held wand that emits primary blue light (λmax=450-470nm) is used to cure the resin within a dental patient's mouth.

Direct dental composites are placed by the dentist in a clinical setting. Polymerization is accomplished typically with a hand held curing light that emits specific wavelengths keyed to the initiator and catalyst packages involved. When using a curing light, the light should be held as close to the resin surface as possible, a shield should be placed between the light tip and the operator's eyes, and that curing time should be increased for darker resin shades. Light cured resins provide denser restorations than self-cured resins because no mixing is required that might introduce air bubble porosity.

 

Direct dental composites can be used for:

• Filling cavity preparations
• Filling gaps (diastemas) between teeth using a shell-like veneer or
• Minor reshaping of teeth
• Partial crowns on single teeth

WHITENING:

Dental bleaching, also known as tooth whitening, is a common procedure in general dentistry but most especially in the field of cosmetic dentistry. According to the FDA, whitening restores natural tooth color and bleaching whitens beyond the natural color. There are many methods available, such as brushing, bleaching strips, bleaching pen, bleaching gel, laser bleaching, and natural bleaching.

Bleaching methods use carbamide peroxide which reacts with water to form hydrogen peroxide. Carbamide peroxide has about a third of the strength of hydrogen peroxide. This means that a 15% solution of carbamide peroxide is the rough equivalent of a 5% solution of hydrogen peroxide. The peroxide oxidizing agent penetrates the porosities in the rod-like crystal structure of enamel and bleaches stain deposits in the dentin. Power bleaching uses light energy to accelerate the process of bleaching in a dental office.

Tooth bleaching is not a modern invention. Ancient Romans, for example, utilized urine and goat milk as a product to make and keep their teeth whiter.

ORTHODONTICS:

Orthodontics, formerly orthodontia (from Greek orthos "straight or proper or perfect"; and odous "tooth") is the first specialty of dentistry that is concerned with the study and treatment of malocclusions (improper bites), which may be a result of tooth irregularity, disproportionate jaw relationships, or both. Orthodontic treatment can focus on dental displacement only, or can deal with the control and modification of facial growth. In the latter case it is better defined as "dentofacial orthopaedics". Orthodontic treatment can be carried out for purely aesthetic reasons with regards to improving the general appearance of patients' teeth. However, there are orthodontists who work on reconstructing the entire face rather than focusing exclusively on teeth.

PORCELAIN VENEERS:

Indications

Veneers are an important tool for the cosmetic dentist. A dentist may use one veneer to restore a single tooth that may have been fractured or discolored, or multiple teeth to create a "Hollywood" type of smile makeover. Many people have small teeth resulting in spaces that may not be easily closed by orthodontics. Some people have worn away the edges of their teeth resulting in a prematurely aged appearance, while others may have malpositioned teeth that appear crooked. Multiple veneers can close these spaces, lengthen teeth that have been shortened by wear, fill the black triangles between teeth caused by gum recession, provide a uniform color, shape, and symmetry, and make the teeth appear straight. Dentists also recommend using thin porcelain veneers to strengthen worn teeth. Thin veneers is an effective option for aging patients with worn dentition. In many cases, minimal to none tooth preparation is needed when using porcelain veneers.

 Contraindications

The problem of overuse of porcelain veneers by certain cosmetic dentists in 'Confessions of a Former Cosmetic Dentist'. He suggests that the use of veneers for 'instant orthodontics' or simulated straightening of the teeth is harmful, especially for younger people with healthy teeth. Leading dentists caution that minor cosmetic or wear is not justification for porcelain or ceramic veneers, the tooth preparation of which may destroy 3-30% of the tooth surface during tooth preparation for veneers, and after 10 years, 50% of veneers are gone, need retreatment, or no longer in satisfactory condition.                                                 

PORCELAIN CROWNS:

All-ceramic restorations

Inlays, onlays, porcelain veneers, crownlays and all varieties of crowns can also be fabricated out of ceramic materials, such as in CAD/CAM Dentistry or traditionally in a dental laboratory setting. CAD/CAM technology can allow for the immediate, same day delivery of these types restorations which are milled out of blocks of solid porcelain which matches the shade or color of the patients teeth. Traditionally, all-ceramic restorations have been made off site in a dental laboratory either out of feldspathic porcelains or pressed ceramics. This indirect method of fabrication involves molds and temporaries, but can yield quite beautiful end-results if communication between the laboratory and the dentist is sound. The greatest difference between these two differing modalities lies in the fact that the CAD/CAM route does not require temporization, while the laboratory-fabricated route does. Some argue that this lack of temporization can result in a decreased need for root canal therapy, as there is no temporary leakage between visits.

Restorations that are all-ceramic require wide shoulder margins and reductions of at least 1.0 - 1.5 mm across the occlusal (chewing) surfaces of the teeth. There are times where this reduction would be considered excessive, just as there are times when previous restorations or pathology require this much removal or more. Arguments against using all-ceramic restorations include a greater chance of fracture, when little to no enamel remains for proper adhesive bonding, or potentially when the patient clenches or grinds their teeth ("bruxes") excessively. Indications for using all-ceramic restorations include more aesthetic results, when metal compatibility issues exist, and when removal of less tooth structure is desired. All-ceramic restorations do not require resistance and retention form and consequently less surface area need be removed and the restoration will still stay in place by virtue of micromechanical and chemical bonding.

Ceramic materials such as lithium disilicate dental ceramics have recently been developed which provide greater strength and life-expectancy of dental restorations.

Longevity

Although no dental restoration lasts forever, the average lifespan of a crown is around 10 years. While this is considered comparatively favorable to direct restorations, they can actually last up to the life of the patient (50 years or more) with proper care. One reason why a 10 year mark is given is because a dentist can usually provide patients with this number and be confident that a crown that the dental lab makes will last at least this long. It should be noted that many dental insurance plans in North America will allow for a crown to be replaced after only five years.

The most important factor affecting the lifespan of any restorative is the continuing oral hygiene performed by the patient. Other factors depend on the skill of the dentist and their lab technician, the material used and appropriate treatment planning and case selection.

Full gold crowns last the longest, as they are fabricated as a single piece of gold. PFMs, or porcelain-fused-to-metal crowns possess an additional dimension in which they are prone to failure, as they incorporate brittle porcelain into their structure. Although incredibly strong in compression, porcelain is terribly fragile in tension, and fracture of the porcelain increases the risk of failure, which rises as the amount of surfaces covered with porcelain is increased. A traditional PFM with occlusal porcelain (i.e. porcelain applied to the biting surface of a posterior tooth) has a 7% higher chance of failure per year than a corresponding full gold crown.

When crowns are used to restore endodontically treated teeth, they decrease the potential of the tooth fracturing due to the brittle devitalized nature of the tooth and provide a better seal against invading bacteria. Although the inert filling material within the root canal blocks against microbial invasion of the internal tooth structure, it is actually a superior coronal seal, or marginal adaptation of the restoration in or on the crown of the tooth, which prevents reinvasion of the root canal.

Advantages and disadvantages

The main disadvantages of restoration with a crown are extensive irreversible tooth preparation (grinding away) and higher costs than for direct restorations such as amalgam or dental composite. The benefits, as described above, include long-term durability and evidence-based success as compared to other restorations or no treatment.

The crowning of two fairly large molars to sling a bridge between them for a missing tooth is a costly and sometimes oversold procedure. The increased food and bacteria trapping of the underside of the bridge often offsets the benefits of the bridge element in maintaining the positions of the opposing teeth and the loss of the ease of use and mouth feel of two big natural teethIt is usually the damage to a tooth that dictates the need for a crown, and alternative treatments are usually less effective.  Risks and benefits can be weighed based on the priorities of the patient.

An example of this occurs when a patient would like to restore an edentulous area between healthy adjacent teeth. Before implants, there were three options:

·       Fixed partial denture (bridge)

·       Removable partial denture

·       No treatment

Those who could afford it were usually told by their dentists that a bridge was their best choice, because it is much sturdier than removable dentures and requires less looking after. When implants became available, however, they were recommended as the best possible treatment, because the virgin teeth adjacent to the edentulous area no longer needed to be cut in order to fit the bridge. The affluent are thus told that a fixed partial denture is no longer desirable, now that implants are available. However, implants are significantly more expensive than a bridge, and the results are generally much less immediate.

Types and materials

 

Comparison between a porcelain-metal dental crown, an all-porcelain dental crown and a porcelain veneer laminate

There are many different methods of crown fabrication, each using a different material. Some methods are quite similar, and utilize either very similar or identical materials.

 

 

 

 

 

 

Metal-containing restorations

Full gold crown

Full gold crowns (FGCs) consist entirely of a single piece of alloy. Although referred to as a gold crown, this type of crown is actually composed of many different types of elements, including but not limited to gold, platinum, palladium, silver,copper and tin. The first three elements listed are noble metals, while the last three listed are base metals. Full gold crowns are of better quality when they are high in noble content. According to the American Dental Association, full gold crown alloys can only be labeled as high noble when they contain at least 60% noble metal, of which at least 40% must be gold.

The process of constructing a full gold crown begins at the dentist's office. The clinician will begin by preparing the tooth by removing enough tooth tissue to allow for the crown. Once the preparation has been finalized the clinician will take an impression which is basically a mold of the patient's mouth. The impression and patient details are sent to a dental laboratory where the dental technician will flow dental gypsum into the impression to make a dental model. This model is an exact reproduction of the situation in the patient's mouth. The dental technician now has the information required to model a wax pattern of the final restoration allowing for the tooth shape, occlusion and preparation. The wax pattern can be removed from the model and a wax sprue pattern is attached. The pattern is now ready to use in the Lost-wax casting technique. It is invested in a gypsum or phosphate-bonded investment material, allowed to set then put into a furnace where the wax is completely burnt out leaving a hole for the gold to be poured in. Once the crown has cooled, the technician can remove the sprue, fit and polish the crown ready for cementation. The crown is returned to the dentists office where they can remove any temporary crown and cement the finished gold crown.

 

Porcelain-fused-to-metal crowns

Porcelain-fused-to-metal dental crowns (PFMs) have a metal shell on which is fused a veneer of porcelain in a high heat oven. The metal provides strong compression and tensile strength, and the porcelain gives the crown a white tooth-like appearance, suitable for front teeth restorations. These crowns are often made with a partial veneer that covers only the aspects of the crown that are visible. The remaining surfaces of the crown are bare metal. A variety of metal alloys containing precious metals and base metals can be used. The porcelain can be color matched to the adjacent teeth.

Restorations without Metal

Chairside CAD/CAM Dentistry

The CAD/CAM method of fabricating all-ceramic restorations is by electronically capturing and storing a photographic image of the prepared tooth and, using computer technology, crafting a 3D restoration design that conforms to all the necessary specifications of the proposed inlay, onlay or single-unit crown; there is no impression. After selecting the proper features and making various decisions on the computerized model, the dentist directs the computer to send the information to a local milling machine. This machine will then use its specially designed diamond burs to mill the restoration from a solid ingot of a ceramic of pre-determined shade to match the patient's tooth. After about 20 minutes, the restoration is complete, and the dentist sections it from the remainder of the unmilled ingot and tries it in the mouth. If the restoration fits well, the dentist can cement the restoration immediately. A dental CAD/CAM machine costs roughly $100,000, with continued purchase of ceramic ingots and milling burs.

Typically, over 95% of the restorations made using Dental CAD/CAM and Vita Mark I and Mark II blocks are still clinically successful after 5 years. Further, at least 90% of restorations still function successfully after 10 years. Advantages of the Mark II blocks over ceramic blocks include: they wear down as fast as natural teeth, their failure loads are very similar to those of natural teeth, and the wear pattern of Mark II against enamel is similar to that of enamel against enamel.

Leucite Reinforced

Popularly known as the "Empress Crown," the leucite reinforced system is superficially similar to a gold crown technique in that a hollow investment pattern is made, but the similarities stop there. A specially designed pressure-injected leucite-reinforced ceramic is then pressed into the mold by using a pressable-porcelain-oven, as though the final all-ceramic restoration has been "cast." The crown that is constructed can be stained and glazed or cut-back and layered with feldspathic ceramic to match the patients natural color and shape.

A study by the Umeå University in Sweden, led by Göran Sjögren, sought to study the effectiveness of leucite-reinforced crowns. Titled “Clinical examination of leucite-reinforced glass ceramic crowns (Empress) in general practice: a restrospective study”, it found Empress crowns cracked at approximately only a 6% rate, with the integrity of 86% of the remaining samples being called "excellent."

Alumina

Alumina was introduced as a dental material in 1989 where the material was slip cast and infused with glass. More recently alumina core have been constructed with a CAD/CAM dentistry technique where a oversized core is milled from a pre-sintered block of Al2O3.^[15] The block is sintered and shrinks to the correct size. This alumina core can be layered with feldspathic ceramics to make a true to life color and shape.^[15]

Zirconia

Zirconia is a very hard ceramic that is used as a strong base material in some full ceramic restorations. The zirconia used in dentistry is zirconium oxide which has been stabilized with the addition of yttrium oxide. The full name of zirconia used in dentistry is yttria-stabilized zirconia or YSZ.

The zirconia substructure of a crown is usually designed on a digital representation of the patients mouth, which is captured with a 3d digital scan of the patient, impression or model. The substructure is then milled from a block of zirconia in a soft pre-sintered state. Once milled the pre-sintered zirconia is sintered in a furnace, where it shrinks by 20% and reaches it full strength of approximately 850MPa.

On the core structure a dental technician can layer an aesthetic ceramic to create the final colour and shape of the tooth. Sometimes a 'monolithic' crown can be made exclusively of the zirconia ceramic with no aesthetic ceramic layered on top. These crowns tend to be dense in appearance with a high value and lack translucency and fluorescence.

DENTURES:

Dentures, also known as false teeth, are prosthetic devices constructed to replace missing teeth, and which are supported by surrounding soft and hard tissues of the oral cavity. Conventional dentures are removable, however there are many different denture designs, some which rely on bonding or clasping onto teeth or dental implants. There are two main categories of dentures, depending on whether they are used to replace missing teeth on the mandibular arch or the maxillary arch.

IMPLANTS:    

Q: What  is the most significant advantage to the mini-implant?

A: The most significant advantage of the mini-implant is that it is a simple procedure for the doctor and patient, it is cost effective and requires no flap or suturing in most cases. Furthermore, the mini-implant can be restored with a permanent crown or bridge restoration.

Q : Could you describe the configuration of the IMTEC mini-dental implants.

A : The mini-implants are 1.8 or 2.3mm in diameter and come in 10, 13, 15 and 18mm lengths. The 13mm and 15mm are the most commonly used. There are two styles of implant configuration. The classic mini-implant had a ball head, square polished neck and threads right up to the neck. The newer version has a polished collar instead of threads just below the neck.

Q : What is the orientation of the correctly inserted mini-implant?

A : The square neck should be set about 3-4mm above the gingival tissue.

Q : What are the indications for selecting the mini-dental implant?

A : We have used the mini-implants to support single crowns, fixed partial dentures and overdentures. There are few contraindications for selecting a mini-implant. For example if you are placing an implant immediately after an extraction, the mini-implant may be too narrow for predictable healing. You might select a wider conventional implant for that kind of a situation.

Q : Do you feel that most general dentists could be comfortable placing and restoring the mini-implants?

A: Absolutely. A general dentist can place mini-implants. As long as you have the proper training and background, you should be able to place and restore these.

Q : Do you have a formula or system for deciding how many mini-implants dental (MDI) to place. For example, in a square maxillary arch how many MDI’s would you place to replace #7-8-9-10?

A : In general we use 1 MDI per anterior tooth and 2 MDI’s for each molar. For example for replacing #7-10 we would use four MDIs. For replacing A maxillary canine we would use an 2.3mm MDI with a max thread.

Q : What is the proper or ideal alignment of the mini-implant? Long axis of the tooth replaced? What would be the alignment planned for an MDI to replace #8? Through long axis of the cingulum of the prior natural
tooth?

A : We place an MDI to replace a maxillary central incisor on the available bone bissecting the buccal and lingual plates. Occasionally we use a custom abutment to angle the implant lingually.

Q : What kind of abutment interface do you have for cementing a crown or fixed partial denture. The most commonly displayed MDI has a ball at the coronal end and a square neck directly subjacent.

A : We cement the crown directly to the ball and square on the implant. The crown is like a pontic with a cylindrical hole under it. We use a resin
cement.

Q : For a maxillary overdenture do you use MDIs to support a bar or would you use free-standing. How many for each.

A : We generally do not use a bar but prefer free standing MDI’s. We use 6-8 MDI’s with the o-balls to support a maxillary complete overdenture with o-rings.