Bite block are constructed in the laboratory and it consist of a baseplate and bite rim. Usually it is used for obtaining the same positions between upper and lower models with the jaws when the mouth is at rest.Base plate is a temporary plate made of acrylic, shellac or wax fixed on models, and bite rim is fixed on it to obtain the bite block. Bite rim is a temporary rim made of composition or wax rim fixed on the baseplate in the same position as the teeth would be.Articulator is an essential mechanism for keeping models in their correct relationship as obtained at the bite stage. It can open and close to reproduce some of the movements of the jaws.Try-in its a stage when the baseplates with teeth attached are then fitted in the surgery to see than they bite together correctly and are of satisfactory appearance. In this stage any alterations in arrangements or shade of the teeth can easily be made.Waxed-up its stage when the denture is returned to the laboratory to be made into finished dentures, which are then fitted in the surgery.Crowding is due to insufficient room for all the teeth, it usually arise from inheritance of jaws which are too small to accommodate 32 permanent teeth.Oral hygiene is set of measures of keeping the teeth free of food debris, thus preventing plaque formation which leads to dental disease.Fluoridation is the addition of fluorides to the public water supply to reduce the incidence of tooth decay.Fluoride is a mineral that occurs naturally in many food and water.Toothpaste is a substance that you put onto a toothbrush to clean your teeth.Disclosing tablet is one kind of tablet that contains a dye which stain red with porpoise to demonstrating plaque in patients teeth. Orthodontics is the branch of dentistry concerned with correction of irregularities of the teeth. Prosthetics is the branch of dentistry concerned with the replacement of missing teeth by denture, in order to restore normal appearance and function.Denture are made in a dental laboratory, on models of the jaw produced by pouring plaster of Paris into an impression of the patients jaw.Plaster of Paris is a powder that usually is used for edentulous impressions. It mixed gently with water in a rubber bowl in the proportions recommended by the manufactures.Impression trays is one kind of tray used for taking impressions for full denture or partial denture. Special tray - is one kind of individual tray that usually is made of shellac baseplate material, acrylic or metal to take a perfectly accurate final impression.Composition is obtained in solid slabs which are softened inn hot water and loaded into the impression tray.Impression paste is modified form of zinc oxide and eugenol cement that usually is used as a thin lining for final composition impression.Articulator paper is a piece of paper used to realize any necessary adjustments to the occlusion, it marks the high spots on the teeth which can then be ground down with a carborundo stone in a handpiece. Malocclusion is a condition what includes abnormal jaw relationship, crowding, supernumerary teeth, missing teeth and sucking habits.Occlusion is the normal relations of the occlusal inclined planes of the teeth when the jaws are closed.Preventive dentistry is instruction in oral hygiene with regular inspection and any necessary treatment for prevention and removal of stagnation areas.Probe is an instrument in dentistry with long, thin and blunted at the end with purpose to measure pockets and to examine the surfaces of the teeth. Face bow is an accessory part of the articulator for recording the position of the upper bite block relative to the mandibular condyles.

Prosthetics 1. What is prosthetics?Is the branch of dentistry concerned with the replacement of missing teeth by denture, in order to restore normal appearance and function.2. How is the artificial replacements called if a jaw is edentulous?Full denture3. What is partial denture?If some teeth are still present in a jaw the replacement is called partial denture.4. What happens if an extracted tooth is not replaced artificially?If a tooth is extracted, and not replaced artificially, the opposing tooth has nothing to bite on and is therefore functionless.5. When does a tooth loose the beneficial cleansing effect of mastication?Having no opposition, it overerupts and loses the beneficial cleansing mastication.6. Why do the 2 teeth on each side of the missing one form additional food trap?Losing the beneficial cleansing mastication between 2 teeth on each side consequently, this space becomes a food trap. 7. Why can the loss of a single tooth give rise to?The loss of a single tooth give rise to caries and periodontal disease in least 3 other teeth.8. Why do missing teeth lead to digestive disorders?Missing teeth lead to digestive disorders because mastication cannot be performed efficiently.9. By what will periodontal disease be aggravated?Periodontal disease will be aggravated by the excessive stress of the teeth.10. Why is it essential to replace missing teeth?Its essential to replace missing teeth to prevent dental and digestive disorders arising.

Impression Materials1. What does the choice of impression material depend on?The choice of impression material to be used depends on various factors, such as condition of the jaws and the presence or absence of teeth.2. Why must manufactures impressions be carefully followed?Each type of material has a different method of preparation and use, and manufactures instructions must be carefully followed if a satisfactory impression is to be obtained.3. How are impressions called?Impressions for full dentures are called edentulous impressions, but for partial dentures are known as partial impressions.4. What material is used for edentulous impressions?Plaster of Paris 5. How is plaster of Paris mixed?The powder is mixed gently with water in a rubber bowl, in the proportions recommended by the manufacturer. 6. How long does it take to set hard in the mouth?It takes a few minutes to set hard in the month and can usually be removed intact.7. What is done if some fragments break off?If some fragments do break off they are retrieved and fitted back into the rest of plaster impression. For this purpose we can use tweezers and sticky.8. When is the impression coated with a separating medium?Before model can be made, the impression must be coated with separating medium.9. What solution is commonly used as a separating medium?Soap solution is commonly used as a separating medium. 10. How can you characterize the advantages and disadvantages of plaster?The advantages of plaster it gives an accurate impression which can be left indefinitely before making the model.The disadvantage is that it cannot be removed in one piece from every undercut areas and is therefore unsuitable for partial impressions.

CompositionThe advantages of composition are this ability to provide the best retention for full denture by means of perfect peripheral seal. When perfect accuracy is not essential, as in first impressions for special trays, composition has de advantages of requiring no mixing, and being so easy and quick to prepare and use.

Alginate1. What impressions are alginate materials used for?Alginate impressions are used for partial impressions.2. How can alginate impressions be withdrawn from undercut areas?Alginate impressions give an accurate impression which can be withdrawn from undercut areas.3. What method are alginate impressions prepared by?Alginate impressions are prepared by mixing the powder and water with spatula in a rubber bowl. 4. Can you describe the procedure of mixing?The tin is shaken before opening to loosen the powder and the water should be at room temperature to give correct setting time. Correct measures of powder and water are mixed vigorously to a smooth consistency. 5. What is the advantage of alginate?The advantage is its elasticity, which makes it the material of choice for partial impressions; and also allows more than one model to be made from the same impression.6. What is the disadvantage of alginate?The disadvantages are: If special care is not taken, alginate undergoes dimensional changes which would produce an inaccurate model. Alginate does not adhere to an ordinary tray so a perforated tray is preferable. 7. Why do dimensional changes take place?The dimensional changes take place because it absorbs water and expand, or lose water and shrink. 8. What must be done to avoid this?To avoid dimensional changes, the model must be made immediately or by wrapping the impression into a wet napkin and sealing it in plastic bag or by keeping it immersed in liquid paraffin. 9. Why cant an ordinary tray be used?Alginate does not adhere to an ordinary tray.

The bite Stage1. Why are the baseplate fitted and trimmed?The baseplate are fitted and trimmed if necessary to make them comfortable. 2. When are bite rims corrected?The bite rims are reduced or increased in height until the jaws are the correct distance apart when the bite blocks are in contact. Grooves are cut in the rims and a softened layer of wax is then bitten between them.3. How can the correct relationship of the jaws at rest be recorded?This squeezes wax into the grooves and permanently records the correct relationship of the jaws at rest.4. What other marks are made on?Marks are also made on the upper bite to indicate the midline of the face and rest position of the upper lip.5. Why does an anatomical articulator entail extra surgery and laboratory time?Best results are obtained if dentures are made on an anatomical articulator although this entails extra surgery and laboratory time.6. What is a face bow?A face bow is an accessory part of the articulator for recording the position of the upper bite block relative to the mandibular condyles.7. How is the protrusive bite taken?The protrusive bite is taken by the patient thrusting his jaw forward and biting on to another layer of wax between the bite blocks. 8. What you know about try-in stage?In this stage the waxed-up dentures are tried in the patients mouth and checked for comfort, stability and occlusion. The patient is given a mirror to see the shade, shape and arrangement of the teeth and if dissatisfied with them, any necessary adjustments can then be made in the surgery. 9. What are the instructions given on the care of dentures? They must be cleaned after meals with a scrubbing brush, soap and cold water. Hot water should not be used as it may damage the plastic. Partial denture must not be worn at night. At night, or any other time when the denture are not worn, they must be kept in a glass of water. It allowed to dry out, plastic is liable to warp and may not fit properly.10. How is each denture fitted?Each denture is fitted in turn to check its retention and stability, any necessary adjustments to the occlusion; it marks the high spots on the teeth which can then be ground down with a carborundo stone in a handpiece.Orthodontics1. What is orthodontics concerned with?Orthodontics is the branch of dentistry concerned with correction of irregularities of the teeth. 2. When are permanent teeth crooked or protruding?The permanent teeth are crooked or protruding when the permanent teeth erupt. 3. What condition is known as malocclusion?Malocclusion is a condition when the permanent teeth are crooked or protruding.4. What are the aims of orthodontics treatment?The aims of orthodontics treatment are to reposition the teeth so that appearance is improved and good functional occlusion obtained. By correction badly positioned teeth if may also eliminate some stagnation areas and help prevent caries.5. What basic types of malocclusion do you know?The basic types of malocclusion are crowding, protruding upper incisors and a prominent lower jaw.6. When does crowding arise?Crowding arise from inheritance of jaws which are too small to accommodate 32 permanent teeth.7. What happens if there is insufficient room left?The teeth become crooked and overlapping, whilst those which normally erupt late cannot take up their proper position as there is insufficient room left.8. How are the teeth usually displaced in these cases?Canines are usually displaced buccaly, second premolars lingually and the lower third molars are impacted.9. What may early extraction also contribute to?Early extraction contributes to the crowding. The gap left by the extraction soon closes, as the back tooth drifts forward and takes up the space required for the permanent successor. 10. Why do many children attend for orthodontics treatment?Many children attend for orthodontics because their upper front teeth protrude between their lips. 11. What condition is commonly associated with an open lip posture?Open lip posture is associated from inheriting a jaw relationship in which the upper teeth are too far forward relative to the lowers.12. What does prominent lower jaw result in?Preeminent lower jaw results in the lower incisors biting in front of the uppers, instead of behind them.

Denture MaterialsUSESADVANTAGESDISADVANTAGES

PlasterEdentulous impressions Accuracy No dimensional changesUnsuitable for partial impressions

Compositions impressions for special trays edentulous impressions with perfect peripheral seal rapid and simple no mixing required best possible retention

takes longer than any other impression unsuitable for partial impressions

AlginatePartial impressionsAccuracy Dimensional changes

Impression paste lining composition impression and baseplates Relining dentures. Accuracy Can be tried in mouth and additions made unsuitable for partial impressions sticks to lips and skin

Oral Hygiene1. What do most disorders arise from?From 2 basic diseases of the teeth and their supporting tissues- caries and periodontal disease.2. Why does prevention of dental disease entail elimination of food stagnation?This is the primary cause of caries and periodontal disease.3. What does food stagnation cause?Plaque formation,leads to acid production, in the case of caries and to bacterial irritation and calculus in periodontal disease.4. What methods of prevention do you know?Oral hygiene,which is the patients responsability, preventive dentistry, dental health education.5. How can plaque formation be prevented?Oral hygiene,which is the patients responsability, preventive dentistry, dental health education.6. What is oral hygiene?Keeping the teeth free of food debris, thus preventing plaque formation which leads to dental disease.7. Why is cleaning best performed by brushing?Is the only way of removing plaque.8. How can food debris be removed if brushing is not possible?It is finishing the meal with a detergent food.9. What detergent food can you name?Firm, fibrous fruits or vegetables, apples, pears, carrots, celery10. What one must do if brushing or eating an apple is not possible?A plain water mouth rinse.11. Is a plain water mouth rinse a satisfactory alternative to brushing?Is better than nothing.12. What is the most effective method of cleaning teeth?Toothbrushing.13. When does tooth brushing remove plaque?When it can only clean away loose food particles.

Toothbrushing1. When can brushing be effective?If it removes plaque.2. What is the object of toothbrushing?Is to clean every accessible tooth surface, thus removing food debris and plaque and massaging the gum margin.3. What toothbrush is the most effective?With a small head and medium bristles.4. How is the brush used?Is rinsed and toothpaste added.. Several strokes are used on each section of the mouth.5. By what motion are buccal, lingual, mesial and distal surfaces cleaned?By a rotary motion.6. How are occlusal surfaces cleaned?By a scrubbing action.7. Why must the gingival margins be cleaned by a backwards and forwards motion?To avoid abrasion of the necks of the teeth.8. Why should the mouth be thoroughly rinsed?To expel food debris dislodgedby the toothbrush.9. Do many people know how to brush the teeth correctly and effectively?Many people lack these requirements and brushing is ineffective as a preventive measure.10. How can the process be made simpler?By using an electric toothbrush.11. Why are teeth cleaned rapidly by using an electric toothbrush?Most of the movements are done automatically.12. Is it better than a properly used ordinary toothbrush?It is no better than a properly used ordinary toothbrush.

Plaque & preventive dentistry1. What does preventive dentistry include?Instruction in oral hygiene, regular inspection and any necessary treatment for prevention and removal of stagnation areas.2. When is instruction in oral hygiene best given?At the chairside, whilst posters and pamphlets in the waiting room serve as an extra reminder.What are patients told?3. How dental disease arises and how it can be prevented?

4. What does the most impressive way of demonstrating plaque contain?Contains a dye which stains it bright red.5. The patients are only shown how to use a toothbrush correctly, arent they?They are advised to clean their teeth after every meal, and warned against snacks between meals.6. How can patients clean their teeth if a toothbrush is not available?The best subtitute in such cases is a detergent food, or plain water mouth rinse.7. Why is cleaning after every meal not enough unless it is combined with dietary discipline?Because it is combined with dietary discipline to stop eating between meals.8. What is better prevention or cure?Prevention is better than cure.9. How often should patients have a regular inspection?Patients should be encouraged to have a regular inspection twice a year.10. In what stage can any dental disease be treated easily?The incipient dental disease can be treated far more easily in its earliest stages than later.11. What will periodic scaling prevent?The onset of periodontal disease before it ever reaches the stages of gingivitis.12. How can you characterize early treatment of caries?Early treatment of caries enables affected teeth to be conserved rather than extracted.

Public health measures. Dental health education1. What can the practitioner explain in his surgery?The causes and prevention of dental disease to individual patients in his surgery.2. It is enough to be explained by the dentists only?No. 3. What groups of population are in need of advice on dental care?Expectant and nursing mothers, parents of schoolchildren and young teenagers.4. Why is much more publicity necessary?To warn these groups of the damage done by dummies used with sweetened fruit juices, of acquiring the habit of unrestricted snacks between meals and evading dental inspection until toothache develops.5. Who must help educate the public?Doctors, midwives, health visitors, clinic staff and school teatchers.6. How can babies become regular patients of dental surgeries?Toddlers will thereby accept the dental surgery as a place of interest and soon become regular and cooperative patients themselves, long before any treatment is necessary.7. What steps should be taken in school?To ensure that school dinners do not leave a film of carbohydrate debris on the teeth.8. Why are regular visits important for teenagers?Of good appearance and this can be utilized in dental health education.9. What means can help in dental health education?Many excellent films, posters and pamphlets.10. Why must the entire population be shown how to maintain good helth?To help reduce the vast amount of dental diseases.11. How can good dental health be maintained?By dietary discipline, strict oral hygiene and regular dental inspection.