1) PritamMohanty et al in 2015 stated that the increased prevalence of enameldemineralization during orthodontic therapy is to an extent due to the surfaceirregularities of fixed appliances, which create areas for plaque retentionrendering oral hygiene maintanance more difficult and hinder self-cleansingmechanisms. These in turn reduce the plaque pH in the presence of fermentablecarbohydrates, increase the rate of plaque accumulation and maturation, andencourage colonization of aciduric bacteria such as Streptococcus mutans andlactobacilli. White SpotLesions: A Challenge to Orthodonics ( JRAD -2015 )PritamMohanty1* Nivedita Sahoo2 Debapreeti Mohanty 2) MizrahiE in 1989 (39) and Benson P in2008 (40) stated that clinicallydemineralized enamel manifests as a surface opacity. Subsurfacedemineralization marks the onset of enamel crystal dissolution leading toformation of pores between the enamel rods which inturn results in roughsurface, loss of surface shine and alterations in refractive index all of whichresult in greater visual enamel opacity, as porous enamel scatters more lightwhen compared to sound enamel. 3) OgaardB et al (41) conducted a clinicaltrial to investigate carious lesion development associated with fixedorthodontic therapy using microradiography and scanned electronmicroscopy. To promote plaqueaccumulation, orthodontic bands were attached to premolars scheduled to beextracted as part of fixed orthodontic treatment.
White spot lesions were observedwithin a month in the absence of any fluoride supplementation. It was concludedthat enamel demineralization associated with fixed orthodontic treatment is arapid process caused by cariogenic activity in the plaque developed aroundbrackets. 4) ZachrissonBU et al (42) conducted astudy including 173 individualsreceiving orthodontic treatment to assess the relationship between incidence ofcaries and oral hygiene during treatment.
Assessments of oral hygiene wereperformed every month by using plaque index and gingival index . Cariouslesions were scored accordingto Caries Index (CI) at the time of debonding .The results showed a definite correlation between oralhealth and caries incidence. With increasing mean PII and GI scores, there wereconcomitant, almost linear increases in mean CI scores.
It was concluded thata strong co-relation exists between oral hygiene and caries incidence inorthodontic patients as compared to in non-orthodontic individuals. 5) OgaardB (43) studied theprevalence of white spot lesions on the buccal surfaces in 19-year-olds including 51 orthodonticpatients and 47 untreated individuals. On the average, 5.7 years had elapsedsince fixed orthodontic appliances were removed. The results of the studyshowed a significant increase in the white spot score and the number of teethwith white spot lesions in the orthodontic group than in the untreated group.
Hence it was concluded that the orthodontic patients have significantlymore WSL than non- orthodontic patients and these WSL may remain unesthetic evenyears after treatment. 6) Artun J et al (45) conducted a study to assess theprevalence, localization and distribution of white spots on buccal toothsurfaces after orthodontic treatment with fixed orthodontic appliances. Thestudy included 3 groups comprising of 2 test groups (A and B) , each comprising60 consecutively treated adolescents treated by two different orthodontist ,and a control group of 60 subjects, who didnot receive orthodontic treatment. Patients in groups A and B were instructed topractice regular oral hygiene measures and were given a prescription of sodiumfluoride for daily rinsing. The fluoride programme was monitored more closelyand patients in group A were encouragedmore frequently than those in group B.The subjects in groups A and B wereexamined 1.8 and 1 year after debonding, respectively. White spots were ratedon a scale of 1 to 3 according to opacity and extension on buccal enamelsurface around the brackets and bondingmaterial during treatment.
The results showed significantly higher scores,especially in gingival areas for both opacity and extension of the lesions ingroup B than in the control group,.No significant differences were noticedbetween group A and the control group and between the test groups. 7) Fournieret al (44) conducted anin-vitro study to assess and compare the affinity of Streptococcus mutans toorthodontic brackets made out of metal, plastic, and ceramic.Twelve saliva-coatedbrackets and 12 non-coated brackets of each type were immersed in a S. mutanssolution labeled with 3H thymidine followed by immersion in distilled water at 20 degrees C for 24, 48,and 72 hours.
The adherence of S. mutans to these samples were measured. Duringthe first 24 hours, the adherence of S.
mutans reduced regardless of saliva coating but between 24 and 72 hours, therewas no change in the adherence of S. mutans to the saliva-coated brackets andthe adherence to uncoated brackets reduced. Saliva coating caused a reductionin the affinity of S. mutans for all products. It was found that the initialaffinity of Streptococcus mutans to metal brackets was significantly lower thanthat to porcelain and plastic brackets regardless of saliva coating.