Dental Indices by Dr. Wafaa Ahmed PDF

Dental indices by: Dr. Wafaa Ahmed / FICMS /CM Epidemiological Indices are attempt to quantitate clinical conditions on graduated scale. Index : a set of values usually numerical with maximum &minimum limits, used to describe variables of specific conditions on gradu...

Dental indices by: Dr. Wafaa Ahmed / FICMS /CM Epidemiological Indices are attempt to quantitate clinical conditions on graduated scale. Index : a set of values usually numerical with maximum &minimum limits, used to describe variables of specific conditions on graduated scale, which use the same criteria &method to compare a specific variable found in a population with that same variable found in other population. Purposes of index : 1- to make accurate assessment of the extent & severity of the disease &to compare the dis status among individuals & communities. 2- to fid out the etiology & predisposing factors for dis. 3- for planning oral health policy.  4- to assess the efficiency of measures undertaken to overcome the dis which may be preventive or curative. Ideal properties of an index: 1- clarity :the investigator should be able to carry out the index rules in his mind. - simplicity : the index should be easy to apply ,so there is no time lost During examination. - objectivity: the index should be clear & un ambiguous. 2- validity : the index should be measure what is intended to measure.so It should correspond with clinical stages of the dis. E.g number of missing teeth in adult is not a valid measure of carries activity &number of bacteria in a sample of saliva is not a valid measure of bacteria of dental plaque.  3- reliability : the index should measure the consistently at different times, &under a variety of conditions, by the same person or different persons. 4-quntifiabilty : the index should be amenable to statistical analysis.so that the status of group can be expressed by a number that correspond to relative position on a scale from zero to the upper limit. 5-Sensitivity : it should be able to detect reasonably small shifts ,in either direction in the condition. 6- Acceptability: it should be not painful or demeaning to the subject.  Types of indices 1- simple index : its measure the presence or absence of a condition. E.g an index measure the presence of plaque without evaluating its effect on gingiva. 2- cumulative index :its measure all evidence of condition ( past & present).e.g DMFT index for dental carries. ( DMFT: The sum of the number of decayed , missing due to carries & filled teeth in the permanent teeth) 3- irreversible index : its measures the conditions that will not return to the normal state. When established cannot decrease in value on subsequent examinations. e.g dental carries index DMF. (DMF: decayed, missing &filled teeth index) 4- reversible index : its measures the conditions that can be changed or reversed as gingival index (GI).  5- composite index :its measure conditions that can return to the normal State & conditions will not return to the normal state as periodontal index (PDI) 6- full mouth indices :these indices are periodontal index & dental fluorosis index. 7-Simplified indices :they measure only representative samples of dental apparatus e.g green & vermilions simplified oral hygiene index. (OHI-S) - indices are also classified in general categories according to the entity which they measure : A- disease index :e.g D( decay)portion of the DMF index is the best example for disease index B- symptom index: e.g measuring gingival or sulcular bleeding are essential example.  C- treatment index : e.g the F(filled) potion of DMF index is the best example. Recommended method of performance of an index : 1- explain procedure to patient 2-drape patient 3- give patient protective eyewear 4- wash hands. 5-wear PPE (personal protective equipment) 6- adjusted position of patient on d. chair. 7- adjusted dental light for maximum illumination 8-Apply lubricant gel to patient lips. 9- dry teeth with compressed air using recommended sequence 10-carry out the index.  L5 epidemiology of dental caries Dental caries :its defined as progressive ,irreversible microbial disease of multifactorial nature affecting the calcified tissue of the teeth ,characterized by demineralization of the inorganic portion &destruction of the organic portion of the tooth. Pathogenesis of caries process: dental plaque on the surface of the tooth consist of a bacterial film. Bacteria within the plaque are acidogenic that they produce acids fermentable when they metabolize carbohydrates. These acids can dissolve the calcium ,phosphate mineral of the tooth enamel or dentine in a process known as demineralization. If this process is not halted or reversed via remineralization (the redeposition of minerals via saliva).its eventually becomes a frank cavity. The critical PH value for demineralization is the range( 5.2-5.5) conversely tooth remineralization can occur if PH of the environment adjacent to the tooth is high. - Dental caries progress process, stops or reverse is depend on a balance between demineralization & remineralization. Normal PH of saliva is (6.2-7.6). Area prone to dental caries :bacterial plaque is the essential precursor of caries. Sites on tooth surface which encourage plaque retention &stagnation are particularly prone to progression of lesions. These sites are : -enamel in pits & fissures on occlusal surfaces of molars & premolars, buccal pits of molars& maxillary incisors. -tooth surfaces adjacent to dentures & bridges which make cleaning more difficult, thus encourage plaque stagnation. -Proximal enamel smooth surfaces just cervical to contact point.  -patients with periodontal dis which results in gingival recession , caries occur on exposed root surface. -the enamel of the cervical margin of the tooth just coronal to the gingival margin. - the margins of restorations, particularly those which are deficient or overhanging. Classification of dental caries: There are deferent classification system for dental caries 1-according to location : a- pit &fissure b-smooth surface c-root surface 2- according to clinical appearance : A- incipient b- cavitation c- gross destruction  3- according to history : a- primary b- secondary or recurrent Susceptibility of different teeth : the Hagerstown study ranks the order of susceptibility of teeth to caries as : 1- mandibular 1st &2nd molars 2- maxillary 1st&2nd molars 3- mandibular 2nd bicuspids ,maxillary 1st&2nd bicuspids, maxillary central &lateral incisors. 4- maxillary canines &mandibular 1st bicuspids 5- mandibular central &lateral incisors, mandibular canines  Factors affecting development of dental caries 1-Host factor s: A- tooth :composition ,morphology ,position B-saliva: composition ,buffering capacity of saliva , quantity & viscosity C- sex d- age e- race &ethnicity f- socioeconomic status g- heredity h- emotional disturbances 2- agent factors : a- microorganism b- dental plaque 3-Environmental factors : A-Diet &nutrition b- geographical variation c- climate D- oral hygiene e- soil f- fluoride  Host factors A- tooth: 1- Morphology of teeth- :morphologic features of teeth play role in development of dental caries the presence of deep narrow occlusal fissure or buccal or lingual pits.these fissures trap food ,bactertia &debris leading to development of caries. 2- Position of teeth: Anterior teeth are less affected by dental caries compared to posterior teeth. Malaligment , out rotated teeth are difficult to clean favoring the accumulation of food & debris which may predispose to development of caries.  3- Composition of teeth: The tooth is composed mainly of inorganic elements (96% in enamel and 70% in dentin) and the remaining are organic materials and water. Inorganic components include majorly calcium,& phosphorous ,while the minor elements are Zinc, copper, strontium, magnesium, fluoride, etc. the enamel surface is more highly mineralized &tend to accumulate grater quantities of fluoride ,zinc ,lead &iron than subsurface of enamel &so that its more resistant to caries.the surface dissolves at slower rate in acids.  B-saliva Its an environmental factor that teeth constantly bathed by it , & this is influence the process of caries teeth. 1- saliva composition : it has critical role in development of caries or its prevention.saliva provided provide calcium, phosphate , proteins, lipids & Antibacterial substances& buffers. - calcium& phosphorus :the quantity of them is inversely related to the rate of flow. There quantities are less in case caries active individuals. - ammonia :as its quantity decrease , caries activity increases, because ammonia retards plaque formation & neutralized acid. -urea : its hydrolyzed to ammonium carbonate by urease which has a neutralizing effect.  -antibacterial properties of saliva :the salivary antibacterial substances or Enzymes are : 1- lacto peroxidase 2- lysozyme 3- lactoferrin 4- IGA 2- buffering & neutralization :saliva buffering can reverse the low PH in plaque. The PH will vary mainly according to the bicarbonate content of the saliva.other components contributing to the ability of saliva to neutralize acid are salivary phosphate , salivary proteins , ammonia , urea ,& statherin.saliva is an alkaline & its an effective buffer system. These properties protect the oral tissues against acids & plaque. The salivary neutralization & buffering effect markedly reduces the carcinogenic potential of foods. As flow rate of saliva increases ,the PH also increases.saliva may be slightly acidic as its secreted at un stimulated flow rate the physical act of chewing gum(un sweetened ,unflavored ) stimulates salivary flow rate (10- 12)times greater than the un stimulated rate. 3- quantity : saliva secreted normally (700-800ml/day).reduction in salivary flow adversely affects dental caries {there is an inverse relation between salivary flow & dental caries ). 4- viscosity of saliva: viscosity of saliva is mainly due to mucin content.as viscosity of saliva increases , the caries activity also increase. C- sex :in younger people caries has been seen to be higher in females than males but some studies show no significant differences.girls may be more prone to caries due to early eruption of teeth , hormonal changes ( puberty & pregnancy ). D- age :although its present in all ages ,but it was believed that dental caries was dis of childhood. WHO data bank has shown a decline in DMFT values  In 12 years old children. Root caries is seen in over( 60 Y)age old people mainly due to exposed root surface because of gingival recession &reduced manual dexterity (tooth brushing ). E-race &ethnicity : many studies showed that (Negroes )blacks of comparable age& sex have lower caries scores than Caucasians. Chines have shown to have lower caries rate than corresponding white population ,these differences are probably more due to environmental factors. F- socioeconomic status :there is an inverse relationship between socioeconomic s status &dental caries experience. G- Heredity :environmental factors have greater effect than genetic factors but later also contribute s to the causation of caries.  H- emotional disturbances: emotional disturbances particularly anxiety tend to increase the incidence of dental caries. Agents factors : A- microorganism s:the mouth has diverse resident microbial flora. The normal inhabitants established early in life.streptococcus mutans & Lactobacillus acidophilus ( acid production bacteria )were found to be associated with formation of dental caries this link was found by epidemiological studies. B-dental plaque :bacterial plaque is a dense non- mineralized ,highly organized mass of bacteria colonies in a gel like inter microbial substances it can be supra gingival (coronal to the gingival margin on the clinical crown of the tooth )&sub gingival (apical to the margin of the ginigiva).  Environmental factors A-Diet & nutrition : types & amounts of food eaten daily by an individuals exerts an effect on caries locally in the mouth by reacting with enamel surface & by serving as substrate for carcinogenic microorganisms.according to the acidogenic or chemoparasitic theory ,dental caries occurs when acid produced by bacteria in dental plaque when refined Carbohydrates are eaten.the presence of refined carbohydrates as sugar is essential for caries development.sucrose is the most carcinogenic of all sugars.in human consumption sucrose accounts for 60%of all sugars eaten. Nutrition its about eating healthy &balance diet.it was showed that severe chronic malnutrition during development of teeth can result in hypoplastic condition & later predispose to dental caries.the malnutrition itself dose not produce caries without exposure to strong cariogenic challenges  B-geographic variation : it was documented that dental caries is decrease in children living in developed western countries. C- climate : sunshine & high temperature areas seems to have lower dental caries (inverse relationship )while areas with more humidity &rainfall have shown increase dental caries. D- oral hygiene: poor oral hygiene shows an increase in the rate of dental caries. So there is an inverse relationship. E- soil: trace elements in soil have shown a relationship with caries.selenium ,magnesium ,cadmium ,lead &silicon presence in soil cause increase caries while molybdenum , vanadium & phosphorus are decrease dental caries. F- fluoride : its presence in water & soil decrease incidence of dental caries.  Primary prevention of dental caries 1- dietary control :eating nutritious balance meals &limit snacks. avoid carbohydrate s such as candy &chips ,which can remain on the tooth surface. 2- oral hygiene: proper brushing &flossing daily remove plaque. 3- xylitol: sucrose is well known as factor cause caries. Increase its intake lead to increase dental caries.sugar substitutes have developed to reduce caries.xylitol is one of sugar substitutes has sweet flavor & its not only cariogenic but also anti cariogenic it keeps sucrose molecules from binding with streptococcus mutans thereby blocking its metabolism , its also reduces the adhesion ability& the number of streptococci. 4- pits & fissures sealants : pits & fissures are more susceptible for dental caries because they are favors for plaque accumulation.these areas are too narrow for any oral hygiene to be effective.  By filling such irregularities with flow able restorative material (fissure sealants) the area becomes less morphologically susceptible. this is recommended especially in young patients with erupting teeth &adults with high caries index. 5-fluoride therapy :fluoride prevent s dental caries by inhibiting demineralization of the tooth & enhancing re mineralization so tooth surface will be resistant to acid attack.in addition fluoride inhibit bacterial enzymes. methods of fluoride application include water fluoridation , fluoride teeth paste , fluoride mouth rinse, dietary fluoride supplements & Professionally applied fluoride compounds such as gels & varnish.  factors contributing to the decline of dental caries in developed countries 1-fluoridation of water supplies. 2-use of fluoride supplements 3- use of fluoride dentifrices 4- availability of dental resources 5- increased dental awareness 6-adoption of preventive approach by practitioner 7- changes in diagnostic criteria 8- decrease in sugar consumption.  Reasons for rise in dental caries in under developed countries 1- increase sugar consumption. 2- lack of dental resources 3- socioeconomic factors 4- lack of water fluoridation 5- lack of preventive dental health programs Good luck