Minimal Invasive Dentistry

MID

1. 1

2. MINIMAL INVASIVE DENTISTRY (MID) Dr. Nabeela Basha Seminar - 15

3. Contents: Introduction History Principles The Minimal intervention approach Caries removal & restoration Recent advances in caries removal techniques Cavity designs for Minimal intervention Restorative materials used in MID Dental Public Health Significance Conclusion Previous year questions References 3

4. 4

5. What is minimally invasive dentistry and how is it different from regular dentistry? The goal of minimally invasive dentistry, or microdentistry , is to conserve healthy tooth structure. It focuses on prevention, remineralization, and minimal dentist intervention. Using scientific advances, minimally invasive dentistry allows dentists to perform the least amount of dentistry needed while never removing more of the tooth structure than is required to restore teeth to their normal condition. 5

6. In addition, in minimally invasive dentistry, dentists use long-lasting dental materials that conserve the maximum tooth structure so the need for future repairs is reduced. http://www.agd.org/public/OralHealthFacts/files/pdfgenerator.aspx?pdf=FS_MinimallyInvasiveDentistry. 6

7. Definition Minimum Invasion Dentistry (MID) is defined as a philosophy of professional care, concerned with the occurrence, early detection and earliest possible cure of disease on a micro level, followed by minimally invasive treatment in order to repair irreversible damages caused by such disease. Tyas MJ, Anusavice KJ, Frencken JE, Mount GJ. Minimal intervention dentistry-a review. FDI Commission Project 1-97. Int Dent J. 2000;50:1–12. 7

8. Golden Triangle of MID A thorough understanding and appreciation of the interplay between three critical factors is required to achieve success clinically when using a minimally invasive operative caries management strategy. 8

9. Timeline of MID developments 1836-1915 GV Black = all softened or discoloured tooth structure was removed and all the walls had to extend out to ‘caries free’ areas. GV Black identified the fact that the presence of bacteria was a necessary factor in caries and suggested that the profession had an obligation to continue to research on this problem. 9

10. In 1895, Wilson reported the placement of dental cement in pits and fissures to prevent caries. In 1923 , Hyatt advocated early insertion of small restorations in deep pits and fissures before carious lesions had the opportunity to develop. He termed this procedure ‘prophylactic odontotomy ’. Disadvantage is that it requires the cutting of tooth structure. In 1929 , Bodecker suggested that deep fissures could be broadened with a large round bur to make the occlusal areas more self-cleansing, a procedure that is called enameloplasty . 10

11. 1940s - Restorative materials: silicate cement with fluoride releasing ions Acid etch technique, introduced first by Buonocore in 1955 , started a new era in preventive dentistry. Etching the enamel and bonding of the sealant material by a resin marked an approach towards a more preventive mode in the caries treatment. 1956 - Miller suggested copper cements, suppressing bacterial activity 11

12. 1970 - Graham Mount proposed MID technique. 1974 - Dan Erikson presented the MID technique to the world. 1976 - Glass ionomer cements were developed. 1978 - Simonsen and Stallard, were the first to describe preventive resin restorations and to report the results of a clinical trial. ART was pioneered in Tanzania in the mid- 1980s as part of a community-based primary oral health program by the University of Dar-us-Salaam. 12

13. 1980-84 - Jo E Frencken used ART technique using polycarboxylates . 1988-90 - Revolutionary period- adhesives were used in ART. 1994 - World Health Day - ART was proposed and accepted at WHO. 1998 - ART use started in clinics. 13

14. PRINCIPLES Disease control by reduction in cariogenic bacteria. Remineralization of early lesions. Avoid removal any more tooth structure than is absolutely required to restore teeth to their normal conditions. Use of dental materials that conserve the maximum of tooth structure. 14

15. Use of only the strongest and longest lasting dental materials to reduce, the need for future repairs and replacement. Repair, rather than replacing defective restorations. Use of dental procedures that keep the number of necessary appointments to the minimum. 15

16. The Minimal Intervention Approach Cariology has advanced over the past 30 years with scientific advances in the knowledge of the caries process in terms of its pathogenesis, its transmission, the demineralization and remineralization continuum, the mode of action of fluoride, but also with respect to the great technological developments in biomaterials, equipment for the detection of caries lesions and methods for cavity preparation. The MI approach includes: Early detection of caries Caries removal and restoration 16

17. Caries diagnosis The fundamental purpose of using caries diagnostic methods is to be able to identify, detect and classify the lesions to select most appropriate intervention for the patient. It includes: A. CARIES RISK ASSESSMENT B. EARLY DETECTION OF CARIES 17

18. CARIES RISK ASSESSMENT Risk is defined as “the probability of an individual developing a given disease” and thus a risk factor is a factor associated with an increased probability of an individual developing a particular disease. Caries risk assessment is the determination of the probability of person’s developing new caries lesions during specific period and the probability of a change in the size or activity of existing lesions over time. 18

19. Since caries is preventable, the diagnosis of caries as a lesion in a tooth is not sufficient for a treatment plan. For this, a proper ‘medical’ diagnosis is required based on certain components. Firstly, caries must be recorded on each surface as either initial lesions (reversible) or cavities (irreversible). Secondly, it should be assessed to estimate the severity of caries. Thirdly it assesses the future caries activity. 19

20. Factors Relevant to Caries Risk Assessment 20

21. EARLY DETECTION OF CARIES Visual and tactile examination and dental radiographs are commonly used methods for caries detection. In recent years, newer caries detection methods and devices have been developed, as traditional caries detection procedures do not detect caries until they have progressed through at least the thickness of enamel. These include: 21

22. 1. Laser fluorescence 2. Fiber-optic transillumination 3. Digital imaging fiber-optic transillumination 4. Ultraviolet illumination 5. Electronic caries detector 6. Dye penetration method 7. Quantitative light-induced fluorescence (QLF) 8. Ultrasound imaging 9. Endoscope / Videoscope 22

23. CARIES REMOVAL AND RESTORATION Rotary instruments used for the treatment of carious lesions have often resulted in a considerable removal of tooth structure. Newer techniques for removal of carious dentin have been developed to minimize this excessive tissue loss. 23

24. PIT AND FISSURE SEALANTS The changes in caries epidemiology in the beginning of the 1990’s and the reporting of slower progression of caries lesions, led to suggestions that sealant use should be targeted to those teeth most prone to develop caries lesions. The development of sealants has progressed from the first generation sealants which were activated with ultraviolet light, through the second and third generations of autopolymerised and visible-light activated sealants, to the fourth generation containing fluoride. First generation sealants are no longer marketed. 24

25. Indications: Deep, narrow pits and fissures. • Recently erupted teeth. Where there are no caries in the proximal surfaces. • Patient with high caries risk though this increases the tendency and need for reapplication. Contraindications: Teeth with occluso -proximal lesions. Teeth with proximal lesions. Teeth that is caries free for 4years or more. Teeth with broad well coalesced pits and fissure. 25

26. Retention rate of PFS Meta-analyses have shown that auto-polymerizing sealants were found to have a five-year retention rate of 64.7%. Resin-based light-polymerizing sealants and fluoride-releasing products showed five-year retention rates of 83.8% and 69.9% respectively. However, poor retention rates of <19.3% were documented for UV-light-polymerizing materials, compomers and GIC based sealants. 26

27. Preventive Resin Restoration (PRR) PRR is indicated in teeth with minimal teeth and fissures decay. In this minimal cavity preparation is required to prevent unnecessary removal of healthy tooth structures for retention. If the decay is limited to enamel then no local analgesia is required. After etching, rinsing and drying the cavity is condensed with a normal composite or GIC. 27

28. TYPES OF PRR Based on the extent and depth of the carious lesions: Type A - Suspicious pits and fissures where caries removal is limited to enamel. Type B - Incipient lesion in dentin that is small and confined. Type C - Characterized by the need for greater exploratory preparation in dentin. 28

29. Survival of PRRs 29

30. ART (Atraumatic Restorative Technique) The Atraumatic restorative treatment is a procedure based on removing carious tooth tissues using hand instruments alone and restoring the cavity with an adhesive restorative material. Goals of ART are: Preserving the tooth structure Reducing infection Avoiding discomfort 30

31. Procedure for ART: 31

32. 32

33. Advantages of ART Easily available inexpensive hand instruments are used rather than the expensive electrically driven dental equipment. As it is almost a painless procedure the need for local anesthesia is eliminated or minimized. ART involves the removal of only decalcified tooth tissues, which results in relatively small cavities and conserves sound tooth tissues as much as possible. Sound tooth tissue need not be cut for retention of filling material. 33

34. The leaching of fluoride from glass ionomer probably remineralizes sterile demineralized dentin and prevents development of secondary caries. The combined preventive and curative treatment can be done in one appointment. 34

35. Disadvantages of ART ART restorations are not long lasting. The average life is two years depending upon the rate of caries activity of the individual oral cavity. Because of the low wear resistance and low strength of the existing glass ionomer materials their use is limited. The continuous use of hand instruments over long period of time may result in hand fatigue. 35

36. Survival of ART restorations 36

37. AIR ABRASION The instrument was first developed in the 1940’s by Dr. Robert Black. It is a method of tooth structure removal that is considered to be an effective alternative to the standard dental drill. It removes tooth structure using a stream of aluminium oxide particles generated from compressed air or bottled carbon dioxide or nitrogen gas. The abrasive particles strike the tooth with high velocity and remove a small amount of tooth structure. 37

38. 38

39. 39

40. Advantages It is painless. Local anesthesia is rarely needed. It works quickly. There is no vibration or pressure to cause microfractures that weaken tooth. There is no production of heat to damage the dental pulp and lesser sound tooth structure is removed. 40

41. Disadvantages Depth of preparation cannot be controlled easily. Must be used in caution when used adjacent to soft tissues as it may lead to surface injuries. The preparation does not render a well-finished surface. Air abrasion can cause subcutaneous emphysema. 41

42. LASERS (light amplification by stimulated emission of radiation) In 1997, the Food and Drug Administration approved the use of Erbium: Yttrium Aluminium Garnet laser for caries removal in the USA. It operates at a wavelength of 2.94 μm and is used for the caries removal, cavity preparation in both enamel and dentine and for the preparation of root canals. Laser treatment is appreciated by patients as they are more comfortable than drilling. 42

43. CO 2 -laser = Caries inhibition up to 82.7% Er : YAG- laser = Reduction in surface lesion depth (root surfaces 39%, enamel surfaces 56%) Nd : YAG-laser (with Duraphat ) = Caries inhibition (pits and fissures 43%, smooth surfaces 80%). 43

44. MICRO-PREPARATION AND FISSUROTOMY BURS Many manufacturers are now producing smaller burs for cavity preparation using MI techniques. The burs are spherical, tapered or elliptical. Examples include fissurotomy burs (SS White, USA) and narrow diamond burs ( Brassler , USA). The instruments are manufactured using a special high-tensile steel to produce a thin neck. 44

45. Used with the aid of magnification, these allow very precise preparation of teeth. Micro-preparation burs allow the dentist to conservatively explore and modify the fissures even when caries has spread laterally along the dentino -enamel junction. 45

46. CARIES DETECTOR DYES In caries removal during cavity preparation, only the soft, heavily infected outer dentin must be removed, whereas the demineralized, uninfected inner dentin should be left. Caries-detecting dyes (e.g.1.0% acid red in propylene glycol) have been developed in distinguishing between the two types of caries. 46

47. OZONE APPLICATION Ozone is part of a natural gas mix that surrounds the earth at high altitude and protects world’s population from excessive UV radiations. The O3 technology was developed by Prof. Dr. Edward Lynch. This technique utilizes O3 gas which is applied to the tooth surface in a controlled manner with the use of heal ozone delivery handpiece. This O3 gas eliminates decay causing bacteria. Once the bacteria are eliminated the treated surface can be restored or left to re-mineralize. 47

48. Chemo-mechanical Caries Removal An alternative to the conventional mechanical removal of caries. The idea of chemo-mechanical caries removal (CMCR) was developed in 1970s by Goldman. The need for local anesthesia is reduced or eliminated as there is little pain during the procedure. 48

49. It is an effective alternative for caries removal because it brings together atraumatic characteristics and bactericide / bacteriostatic action. The chemicals used can be in the form of liquid ( caridex ) or gel ( carisolv ). 49

50. Caridex It was developed by CM Habib from a formula made of N-mono - chloroglycine and amino butyric acid and was called as GK 101 E. It gained FDA approval in 1984. It was initially introduced on the US market in 1985. The system involved the intermittent application of preheated N-monochloro-DL-2-aminobutyric acid (GK-101E) to the carious lesion. 50

51. The solution was claimed to cause disruption of collagen in the carious dentine, thus facilitating its removal. Disadvantages- 1. Expensive 2. Large quantity required 3. Solution has to be heated 4. Short shelf-life 51

52. Carisolv Carisolv ( MediTeam Dental, Göteborgsvägen , Sweden) is a chemo-mechanical method of removing dental caries that is minimally invasive. It constitutes amino acids and 0.5% sodium hypochlorite and is applied to the dentin. 52

53. The new system is marketed in two syringes: Red Gel : Glutamic acid, leucine, lysine, sodium chloride, erthrosine , water and sodium hydroxide. Transparent Gel : 0.5% Sodium hypochlorite The average time required for complete caries removal is about 9-12 minutes and the volume of gel utilized for this purpose is only 0.2-1.0 ml. 53

54. Procedure The 2 gels are mixed in equal amounts at room temperature. The mixture is applied using hand instruments onto the decayed dentin. Wait for 30 seconds to allow dissolution of carious dentin. Special instruments are then used to remove softened caries. The instruments designed to scrape in two or in several directions, reduce the friction during caries removal. When caries is excavated, remove all the gel, wipe with a cotton pellet and rinse with lukewarm water. Check with an explorer to ensure that no more soft dentin is remaining. 54

55. 55

56. Advantages: Very effective method of caries removal. Unlike the caridex system, carisolv dissolves only the carious dentin and keeps the healthy dentin intact. Disadvantages: Despite its effectiveness, carisolv was not a blockbuster mainly because it required- Extensive training of professionals. Customized instruments which are costly. 56

57. Papain Gel To overcome the disadvantages of carisolv system, in 2003, a research project in Brazil led to the development of a new formula to universalize the use of chemo-mechanical method for caries removal and promote its use in public health. 57

58. The new formula was commercially known as Papacarie . It is available in syringe form which contains blue-colored gel. 58

59. It is basically composed of Papain, chloramines, toluidine blue, salts, thickening vehicle, which together are responsible for the papacarie’s bactericidal, bacteriostatic and anti-inflammatory characteristics. Papain comes from the latex of the leaves and fruits of the green adult papaya. 59

60. Papain promotes: Chemical debridement Granulation and epithelialization, which hastens the phases of cicatrization Stimulation of the tensile strength of the scars. 60

61. Procedure Apply Papacarie in the carious dentin. Wait for the gel to act for 40-60 seconds. Scrape the softened dentin using old/blunt curettes as specified by the manufacturer. The gel can be reapplied as many times till the colour of the gel remains unchanged. 61

62. RESTORATIVE MATERIALS USED IN MID Newer generation of materials known as SMART materials are used in MI procedure. The new composite resins are showing great success because they visually reflect, refract, & absorb light in similar manner as natural dentition. When esthetic materials ( eg , composite resin, RMGIC, etc ) are able to mimic the physical properties of the human dentition, biomimetic results can ultimately be attained 62

63. It implies that the material will be biocompatible, that is- biologically acceptable to and not rejected by adjacent vital tissues. It has also been shown recently that it is safe to leave the softened, demineralized, affected, but sterile, dentin on the floor of the cavity. If the cavity is then sealed with a biomimetic restoration that releases calcium, phosphate, and fluoride ions the result will be remineralization and healing of the underlying dentin. 63

64. 64

65. 65

66. CAVITY DESIGNS FOR MINIMAL INTERVENTION Tunnel Preparation Slot Cavity Preparation “Minibox” Approximal Cavity Preparations “Full Box” Approximal Cavity Preparation 66

67. Tunnel Preparation It could be used when the lesion is more than 2.5 mm below the crest of the marginal ridge and the contact area may remain sound and the marginal ridge may be quite strong. (Wilson and Mc Lean, 1988). Access to the lesion through the occlusal surfaces should be limited to the extent required to achieve visibility and should be undertaken from an area that is not under direct occlusal load (Knight, 1984). 67

68. Access may be gained through the occlusal surface with No. 2 bur about 2.0 mm from the marginal ridge. Resin-modified glass ionomer cement is the current material of choice for this restoration. They are radiopaque and have been shown to prevent microleakage. 68

69. 69

70. “SLOT CAVITY PREPARATIONS” It could be used when the lesion is less than 2.5 mm below the crest of the marginal ridge. The basic principles of cavity design remain the same, with the objective of removing only that tooth structure that has broken beyond the possibility of remineralization. 70

71. “Minibox” Approximal Cavity Preparations In this preparation, the excavation of the dentin lesion is same as for the previous preparations. The design differs only in the handling of the enamel. Initially, the integrity of enamel wall needs to be preserved by extending the margins where it can be considered stable and durable. A full box need not to be developed. 71

72. It is preferable to retain and reinforce this enamel even if it is unsupported by dentin by placing glass ionomer cement base. 72

73. “Full Box” Approximal Cavity Preparation It is a very common procedure, where the enamel is in hopelessly poor condition and needs refining after eradicating the dentin lesion. The final refinement will depend on the type of restoration to be placed. For example, the preparation design for an amalgam or composite restoration differs from the design for a porcelain or gold inlay 73

74. 74

75. Dental Public Health Significance of MID Implementation of the MID approach in community dental clinics would enable the management of dental caries as a disease process through identification of its aetiologies and addressing these through clinical and health promotion mechanisms. A change in culture, through education and practice, is required to instill the paradigm shift from surgical management of the disease to one of prevention 75

76. Extensive demand for emergency services and long wait lists for adults in the public sector make it difficult to see adult patients regularly to enable early identification of oral disease and implementation of early intervention protocols to prevent progression to irreversible oral disease. There is also a requirement for education and information to assist patients in understanding the implications of the MID approach to treatment 76

77. There is also a major need to analyze the cost-benefit ratio of MI techniques, so that the effectiveness can be more convincingly demonstrated to the many providers. In order to implement an MID approach there needs to be significant investment and resourcing by government. 77

78. CONCLUSION It is time for changes in the principles of operative dentistry. The disease should be treated first; the surgical approach should be undertaken only as a last resort and efforts should be made to preserve a maximum amount of sound tooth structure. Although further research is needed, it can so far be concluded that minimum intervention has the potential to apply a more conservative approach to caries treatment and health orientated treatment option. 78

79. PREVIOUS YEAR QUESTIONS Principles of MID. [7 marks, RGUHS Oct 2010 ] Minimal invasive dentistry. [7 marks, RGUHS July 2017 ] Chemo-mechanical methods of caries removal. [7 marks, RGUHS Nov 2017 ] Minimal Invasive treatment [10 marks Sumandeep Vidyapeeth Dec 2009] 79

80. REFERENCES Hiremath SS. Textbook of Public Health Dentistry. 3rd edition. Elsevier Publishers, New Delhi; 2016. Mickenautsch S. An introduction to minimum intervention dentistry. Singapore Dent J.2005 Dec;27(1)1-6. Deise Cruz Oliveira. Minimally invasive dentistry approach in dental public health. University of Iowa Iowa Research Online 2011 Carol A, Mary E. Minimally Invasive Dentistry. JADA, January 2003 ;134:87-95. 80

81. Banerjee A. Minimal intervention dentistry: part 7. Minimally invasive operative caries management: rationale and techniques. British Dental Journal 2013; 214(3): 107-111. Tyas MJ, Anusavice KJ,  Frencken JE, Mount GJ. Minimal intervention dentistry — a review FDI Commission Project 1–97. International Dental Journal February 2000; 50(1):1-12. Mount GJ. Minimal intervention dentistry: Cavity classification and preparation. J Minim Interv Dent 2009;2(3). Alonso et al. Minimal Invasive Dentistry: Bond Strength of different sealant and filling material to enamel. Oral Health Prev Dent 2005;3(2):87-95. 81

82. Anuradha P, Yadav R. Minimal Invasive Dentistry: Benefits and Challenges. Arch of Dent and Med Res 2016;2(2):25-26. Garg et al. Minimal Invasive Dentistry - A Comprehensive Review ; BJMMR 2016, 17(5): 1-9; Article no.BJMMR.27526. Gujjar KR & Sumra N. Minimally Invasive Dentistry - A Review. International Journal of Clinical Preventive Dentistry, Vol. 9, No. 2, June 2013: 109-120. 82

83. 83