RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE,

KARNATAKA

ANNEXURE II

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

1 / NAME OF THE CANDIDATE AND ADDRESS / DR. LIBINA ISAHAK
POST GRADUATE STUDENT,
DEPARTMENT OF PEDODONTICS AND PREVENTIVE DENTISTRY,
COORG INSTITUE OF DENTAL SCIENCES,
VIRAJPET-571218.
2. / NAME OF THE INSTITUTION / COORG INSTITUTE OF DENTAL SCIENCES,
VIRAJPET-571218,
COORG
3. / COURSE OF THE STUDY AND SUBJECT / MASTER OF DENTAL SURGERY
PEDODONTICS AND PREVENTIVE DENTISTRY
4. / DATE OF ADMISSION TO THE COURSE / 24th MAY 2012
5. / TITLE OF THE TOPIC:
“COMPARATIVE EVALUATION OF TWO NOVEL MECHANO-ROTARY
INSTRUMENTATION TECHNIQUES IN SELECTIVE DENTIN
CARIES REMOVAL: AN IN-VIVO STUDY”
BRIEF RESUME OF THE INTENDED WORK
6.1 NEED FOR THE STUDY:
Dental caries is considered one of the most serious dental diseases that results in localized dissolution and destruction of the calcified tooth tissues and eventually leading to the infection of the dental pulp when left untreated.1 Dentinal caries can be classified into several different layers. The outer layer is highly infected with bacteria and collagen fibrils which are irreversibly denatured. The inner caries affected layer, invaded by fewer bacteria, has limited collagen denaturation and is capable of remineralisation.2 This caries affected dentin is useful because of its lower permeability compared to healthy dentin and its ability to protect pulp from any remaining bacteria in the affected dentin.3 There is no need during caries excavation to remove the inner carious affected layer.
There are number of techniques available for selective removal of carious dentin. These include mechanical rotary or non rotary instruments, chemo-mechanical techniques and lasers. The non-rotary/ non invasive techniques include air abrasion, air polishing, ultrasonic and sono abrasion.3
The traditional approach using mechanical rotary instruments is not fundamentally conservative because it often results in cavity preparation extending beyond the infected caries layer into the non infected or likely infected inner caries dentin or into the normal dentin.3 Thus the concept of minimally invasive restorative dentistry came into existence.
In minimal invasive restorative dentistry, the primary aim is to remove only the outer layer of highly infected, denatured caries infected dentin. This facilities the preservation of the inner layer of intact, bacteria-free reminerlizable caries affected dentin and prevent disease progression.4
Conventional carbon steel burs are considered to be the gold standard, because these burs enjoy the patronage of most of the dental practitioners. A novel, recently proposed, self limiting concept in mechanical caries removal has been brought by the introduction of a polymer bur, (‘Smart Prep-II®’, SS White Burs, Lakewood, USA).5 Smart Prep® bur is made of a polyamide/imide polymer with a specific hardness of 50 KHN, which is higher than the hardness attributed to carious dentin, but lower than that of sound dentin.6
A new line of slow speed rotary cutting instruments is also now commercially available for selective removal of caries dentin. ‘CeraBur®’ (Komet-Brasseler; GERMANY).7Ceramic burs have been proposed to have highly efficient excavating ability on soft carious dentin with minimal reduction of tooth structure.
The purpose of this clinical study is to evaluate and compare the efficacy, efficiency and patient perception of selective removal of carious dentin using a Conventional steel bur, Polymer bur and Ceramic bur.
6.3 REVIEW OF LITERATURE
In routine dental treatment, diamond coated rotating instruments with high speed hand pieces are used to remove carious dentin. These conventional burs are difficult to control because of its high cutting efficiency of dentin with little tactile feedback.4
Special polymer burs have been proposed recently as an alternative to conventional method of carious dentin removal. The manufactures’ product information on ‘Smart Prep®’ (SS White USA) states that this polymer bur will be able to distinguish between the two layers of carious dentin during rotary excavation. This minimally invasive excavation has the advantage of fewer dentinal tubules being cut and thereby less pain sensations being triggered compared to conventional bur .8
“Smart Prep®” burs are made up of polyamide/imide polymer, possessing slightly lower mechanical properties than sound dentin. If the bur touches sound or affected dentin, it quickly becomes dull and produces undesirable vibration and making further cutting impossible.9 This mechanism of action has been said to allow a self limiting, less invasive/less destructive dentin caries excavation, selectively removing only the softened, infected, non reminerlizable dentin and thus conserving tooth substance.10
Dammaschke T and co-workers 8 reported that Smart Prep® polymer bur seemed to be less effective in the excavation of carious dentin when compared to tungsten carbide burs.
Another study reported by Erdemli E and co-workers 2 stated that Smart Prep® bur is an efficient, selective removal instrument for infected carious dentin while preserving the harder, caries affected dentin. They also opined that total bacterial counts reduction with carious dentin preparation by first generation polymer Smart Prep® burs were microbiologically as effective as conventional burs.
Another similar study conducted by Shakya V and co-workers4 reported that the Smart Prep® bur was more conservative in selective dentin caries excavation removal than conventional burs; but time consuming compared to conventional burs.
The disadvantage of Smart Prep® bur is that by keeping to the recommendation to excavate caries from the centre to the periphery in order to avoid contact with sound tooth tissue, the bur would be prematurely and irreversibly damaged.9
Recently, a new bur manufactured from a special alumina based ceramic with stabilized zirconia was introduced to the market. (Cerabur®-Komet Brassler, GERMANY).Cerabur® instruments look like conventional burs and are available in 4 international organization for standardization sizes 014, 010, 018 and 023.Cerabur® instruments are recommended to be used in a slow running hand piece at a speed of 1,000min-1 to 1,500 min – 1. 7
The advantages of these burs in dentin caries excavation is their optimal cutting efficacy, smooth pleasant operation and absence of corrosion.7 Ceramic burs exhibit highly efficient excavating ability on soft carious dentin, with minimal reduction of the sound, hard tooth structure. Hence, Ceramic burs should be suitable for minimally invasive caries excavation. Dammaschke T and co-workers11 reported that Ceramic burs are as effective in dentin caries removal as Conventional burs.
6.3  AIMS AND OBJECTIVES OF THE STUDY
1.  To evaluate and compare the efficacy of selective carious dentin removal using Conventional steel bur, Polymer bur and Ceramic bur.
2.  To evaluate and compare, the time taken for selective carious dentin removal using Conventional steel bur, Polymer bur and Ceramic bur.
3.  To evaluate and compare, the patient comfort during dentin caries removal using Conventional steel bur, Polymer bur and Ceramic bur.
4.  To evaluate and compare, clinically and by digital radiography the restorations placed immediately and at the end of 6 months following selective carious dentin removal using Conventional steel bur, Polymer bur and Ceramic bur.
MATERIALS AND METHOD
7.1 SOURCE OF DATA
STUDY DESIGN-clinical (in –vivo) cross over study-split mouth design.
STUDY SOURCE- 40 patients visiting the Out-patient Department of Pedodontics and Preventive Dentistry, Coorg Institute Of Dental Sciences, Virajpet.
7.2 METHOD OF COLLECTION OF DATA
SAMPLE SIZE:
After obtaining approval for the study design from the Ethical Clearance Committee of the Institutional Review Board and parental/patient consent, forty children in the age group of 8-14 years irrespective of race, sex and socioeconomic status will be selected for the study.
INCLUSION CRITERIA
·  Children in age group of 8-14 years irrespective of race, sex and socioeconomic status having at least three occlusal carious lesions on any of the maxillary/mandibular first permanent molars in any of the quadrants of the dental arch, with dentinal involvement as evidenced by digital radiographs and with an opening occlusal diameter of at least 2mm.
·  First permanent molar teeth which display a positive response to sensibility testing using heat, cold and mechanical stimulation.
EXCLUSION CRITERIA
·  Subjects with Rampant Caries.
·  Subjects who are uncooperative/ physically/mentally challenged.
·  First permanent molar teeth with buccal/ palatal/ proximal/ cervical carious lesions.
·  First permanent molar teeth that do not respond to any form of sensibility testing.
PROCEDURE:
Forty children in the age group of 8-14 years with at least three occlusal carious lesions on any of the maxillary/mandibular first permanent molars will be selected for the study.
The selected carious first permanent molar teeth in each patient will be randomly assigned to one of the following groups: Steel bur group, Polymer bur group
or the Ceramic bur group.
The treatment type for each tooth and the sequence of treatment will be decided using a table of random numbers. The type of the lesion will be determined by its opening size (2-3mm, 4-5mm & >6mm) 4, as measured by a graduated periodontal probe and its consistency (soft, medium hard)4 as determined using a sharp probe.
A single trained operator will perform selective dentin caries excavation procedures in all the subjects. All procedures will be performed without local anesthesia, under rubber dam isolation.
Group I: Control group – Steel bur
In teeth where there is insufficient access to carious dentin, an access will be prepared using a high speed drill. The remaining carious dentin will then be removed using carbon steel round burs.
Group II: Polymer bur group
After obtaining sufficient access, soft carious dentin will be removed using polymer bur (Smart Prep® –SS White Burs; USA) sizes #2, 4 and 6 depending on the cavity sizes.
Group III: Ceramic bur group
After obtaining sufficient access, soft carious dentin will be removed using Ceramic bur (Cera Burs®-K1SM).
Caries removal in all the teeth will be terminated when the operator believes that all the soft dentin has been removed, as verified with a sharp probe.
The amount of time taken to remove caries will be recorded using a stop watch. The efficacy of caries removal will be confirmed both by visual and tactile criteria4 by two blinded co-investigators.
The cavities will then be restored with reinforced glass ionomer cements as interim restoration, with placement of a calcium hydroxide base where ever deemed necessary.
Patient acceptance of the procedure will be carried out immediately after treatment using a questionnaire.
At the end of the restorative procedures two blinded co-investigators will also assess the restorations clinically and by digital radiography.
The subjects will be recalled at the end of 6 months and re-assessment of the restorations will be done clinically and by digital radiography.
The data obtained will be tabulated and analysed statistically.
STATISTICAL ANALYSIS:
Statistical analysis will be done using:
ANOVA
CHI- SQUARE TEST
KRUSKAL-WALLIS TEST
7.3   DOES THE STUDY REQUIRE ANY INVESTIGATIONS OR INTERVENTIONS TO BE CONDUCTED ON PATIENTS OR OTHER HUMANS OR ANIMALS? IF SO, PLEASE DESCRIBE BRIEFLY.
Yes. The procedure involves treatment of dentinal caries lesions in human subjects. The study also involves digital radiographic assessment of selected teeth in these subjects.
7.4 HAS THE ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR INSTITUTION IN CASE OF 7.3?
-YES-
8. LIST OF REFERENCES
1.  Avinash A, Grover S D, Koul M, Nayak M T, Singhvi A, Singh R K.Comparison of mechanical and chemo mechanical methods of caries removal in deciduous and permanent teeth :A SEM Study. J of Indian soc pedod prev dent. 2012; 30(2):115-21.
2.  Erdemli I, Olmez A, Akca G, Sultan N. A microbiological assessment of polymer and conventional carbide burs in caries removal. Pediatr Dent. 2010; 32(4):316-22.
3.  Prabhakar A, Kiran N K. Clinical evaluation of polyamide polymer burs for selective carious dentin removal. J of Contemp dental practice. 2009; 10(4): 26-34.
4.  Shakya VK, Chandra A, Tikku A, Verma P, Kumar R Y. A comparative evaluation of dentin caries removal with polymer bur and conventional burs-An in vitro study. J of Stomatology. 2012; 2: 12-15.
5.  Daniel W, Boston D. New devices for selective dentin caries removal. Quintessance Int, Indian edition. 2004; 3:40-47.
6.  Sliva N, Carvalho R M, Peguraro L F, Tay F R, Thomson V P. Evaluations of a self limiting concept in dentinal caries removal. J of Dent Res. 2006; 85:282-86.
7.  High performance ceramics for tactile excavating [Internet]. [Cited on 2012?]; Available from http://www.komet dental.de/uploads/media./410453V0_PI_EN-k1sm.pdf.
8.  Dammaschke T, Rodenberg TN, Schafer E, Ott KHR. Efficiency of the polymer bur smart prep compared with conventional tungsten carbide bur in dentin caries excavation. Oper Dent .2006; 31(2):256-60.
9.  Almeida A N, Coutinho E, Vivan M C, Lambrechts P ,Van B M. Current concepts and techniques for caries excavation and adhesion to residual dentin. J Of Adhes Dent. 2011; 13(1): 7-22.
10. Meller C, Welk A, Zeligowski T, Splieth C. Comparison of dentin caries excavation
with polymer and conventional tungsten carbide burs. Quintessance Int . 2007; 38
(7):565-69.
11. Dammaschke T, Vesnic A, Schafer E. In vitro comparison of ceramic burs and conventional tungsten carbide burs in dentin caries excavation. Quintessance Int. 2008; 39(6):495-99.
9. / Signature of the candidate / DR. LIBINA ISAHAK
10. / Remarks of the guide
11. / Name & Designation of (in block letters)
11.1 Guide
11.2 Signature / DR. AMEET J. KURTHUKOTI
PROFESSOR
11.3 Co- guide (if any)
11.4 Signature
11.5 Head of the Department
11.6 Signature / DR. B.M. SHANTHALA
PROF. & H.O.D.
12. / 12.1 Remarks of the Chairman & Principal
12.2 Signature / DR. SEQUEIRA PETER SIMON