ENDODONTOLOGY Volume: 27 Issue 2 December 2015 ORIGINAL RESEARCH Effect of addition of Fluoride on Enamel remineralization potential of Sai Kalyan S. 1, Wagle Rahul 2, Chandki rita 3, Byakod Praveen 4, Shaikh Shoaib Yakub 5 1 Reader, 2,4 Professor, 5 Professor and Head, Department of Conservative Dentistry and Endodontics, Rural Dental College, Loni, Maharashtra, India. 3 Senior Lecturer, Department of Conservative Dentistry and Endodontics, Index Institute of Dental Sciences, Indore, India. Corresponding Author: E-mail: s_saikalyan@rediffmail.com Abstract: Aim: To compare and evaluate the effect of commercially available products containing CPP-ACP (GC Tooth mousse, Recaldent; GC corp, Japan), CPP-ACP+ fluoride (GC Tooth Mousse Plus, Recaldent; GC corp, Japan), Novamin (Vantej, Reddy laboratories, India), and NovaMin +fluoride (Sensodyne Repair and Protect, Glaxo Smith Kline, Ontario, USA) on remineralization of enamel as assessed by Enamel micro hardness recovery. Materials and methods: Enamel slabs obtained from 30 extracted maxillary central incisors were evaluated for baseline micro hardness and then subjected to demineralization. After remineralization cycle using different products, mean and surface changes in micro hardness were measured and compared for different groups. Results: A statistically significant difference was found between mean values of % micro hardness when compared as Group I v/s II, III, IV and Group II v/s III, IV, and Group III v/s IV (i.e. p<0.01). Novamin+Fluoride performed the best followed by Novamin, CPP-ACP+Fluoride & CPP-ACP. Conclusion: Novamin based products show superior performance over CPP-ACP based products and that addition of Fluoride to either of these has a synergistic effect on remineralizing potential of these materials. Keywords: Enamel remineralization, Surface microhardness, Fluoride, Novamin, Casein Phospho-peptide Amorphous Calcium Phosphate (CPP-ACP). Introduction Dental caries was identified as a process that may show decalcification as early as 1886 1, Still a large aspect of dentistry till date is focused on restoring the symptoms or repairing the damage resulting from this bacterial infection rather than treating its etiology. The core principles supporting risk-based caries management are decades old, and many practitioners are reluctant to abandon these age old principles and adopt new ones as their current standard approach in patient care. Dental caries has been recognized as a dynamic process that results from an imbalance between the physiologic demineralization and remineralization of tooth structure. 2 It has been well established that tooth undergoes cyclic demineralization of enamel crystals with periods of remineralization resulting from reprecipitation of calcium and phosphate ions from the saliva. If the process of demineralization dominates, caries result. However, if remineralization dominates alongwith removal of bacterial infection, enamel integrity gets restored. 3 This basic knowledge of carious process brings us to an understanding that by controlling the amount, pattern and rhythm of demineralization and remineralization, carious lesions can either be controlled from progressing further or can be reversed. Remineralization is the process of restoring solid minerals through the transfer of cations and anions to the nucleation sites where the lattices leading to the mineral structures are generated. 4 Since remineralization occurring naturally in oral environment is often inadequate for maintaining strong decay free enamel and dentin, the process needs to be augmented by using some external means. It has been proposed that a simultaneous supply of calcium, phosphate and fluoride ions might serve as an invaluable tool to remineralize and strengthen the tooth structure by formation of calcium fluorapatite. 5 Fluoride as a constituent of drinking water and in the form of various topically applied products have a long successful history of use as a caries preventive agent. In recent times, use of bioactive materials like Casein Phospho-peptide Amorphous Calcium Phosphate (CPP-ACP) and Novamin that are known to induce remineralization of dental hard tissues has gone up. But there is limited research to ascertain if there is any synergistic effect on combining anticariogenic activity of fluoride ions with these remineralization systems. This study was done to compare and evaluate the effect of commercially available products containing CPP-ACP (GC Toothmousse, Recaldent; GC corp, Japan), CPP- Endodontology, December 2015;27(2):113-117 113
Effect of addition of Fluoride on Enamel remineralization potential of ACP+ fluoride (GC Tooth Mousse Plus, Recaldent; GC corp, Japan), Novamin (Vantej, Reddy laboratories, India), and NovaMin +fluoride (Sensodyne Repair and Protect, Glaxo Smith Kline, Ontario, USA) on remineralization of enamel under simulated intraoral conditions. Materials and Methods 30 extracted maxillary central incisors were collected and sectioned at root level. The crown portions so obtained were thinned from the palatal side to form an enamel slab of dimensions 1mm ± 0.1. These slabs were then evaluated for initial microhardness using an auto Vickers hardness tester at a load of 50gm for a period of 5 seconds. (Figure 1) This baseline evaluation was made to allow comparative evaluation of changes that occur as a result of enamel lesions and ph cycling. Five indentations were made at a uniform spacing of 100 microns and the average was considered the mean base line micro hardness (SMH) for a particular sample. Then these were subjected to a demineralizing process for 48 hours using a solution which contained 6 2.2mM CaCl 2 2H 2O 2.2mM NaH 2PO4 7H 2O 0.05M Lactic Acid 0.5ppm Fluoride Enamel lesions were then induced and all the specimens were subjected to the evaluation of surface micro measurements under 50 gram loads for five seconds each. Each specimen was then sectioned into 2 halves (total 30x2=60Specimens) and then embedded into a custom made intra-oral device which was a modified version of the lower appliance described by Creanor et al. 7 The subjects were informed to wear the appliance for 8 hours a day (8 A.M-2 P.M, and 7 P.M-9 P.M) and use the therapeutic agent twice a day as recommended. When not in use, the appliance was placed in synthetic saliva. 60 specimens (15 sections per group) of enamel were subjected to different surface treatments as follows, Group 1- CPP-ACP (GC Tooth Mousse, Recaldent; GC corp, Japan) Group 2- CPP-ACP+ Fluoride (GC Tooth Mousse Plus, Recaldent; GC corp, Japan) Group 3- NOVAMIN (Vantej, Reddy laboratories, India) Group 3- NOVAMIN + Fluoride (Sensodyne Repair and Protect, Glaxo Smith Kline, Ontario, USA) After 15 days of treatment the samples were detached from the intraoral device and subjected to micro hardness testing. Percentage of mineral recovery of the surface micro hardness were determined by a formula, 8 Data so obtained was Statistically analysed (Table 1) followed by multiple comparisons (Table 2) to detect significant statistical differences if any. Fig. 1: Micro hardness estimation using Vickers testing machine Table 1: Percentage micro hardness recovery of enamel Group I Group II Group III Group IV Mean ± SD Mean ± SD Mean ± SD Mean ± SD 18.87±3.57 36.79±7.29 60.55±7.16 75.56±7.32 Endodontology, December 2015;27(2):113-117 114
Effect of addition of Fluoride on Enamel remineralization potential of Table 2: Pairwise Comparsions of Enamel microhardness recovery amongst various groups (I) Intervention (J) Intervention Mean Difference (I-J) Std. Error Sig. a 95% Confidence Interval for Difference a Lower Bound Upper Bound CPPACP CPP-ACP+ -17.917 * 2.379.000-24.424-11.409 NOVAMIN -41.679 * 2.379.000-48.187-35.172 NOVAMIN+FL -56.685 * 2.379.000-63.193-50.178 CPP-ACP+ CPPACP 17.917 * 2.379.000 11.409 24.424 NOVAMIN -23.763 * 2.379.000-30.270-17.255 NOVAMIN+FL -38.769 * 2.379.000-45.276-32.261 NOVAMIN CPPACP 41.679 * 2.379.000 35.172 48.187 CPP-ACP+ 23.763 * 2.379.000 17.255 30.270 NOVAMIN+FL -15.006 * 2.379.000-21.514-8.498 NOVAMIN+FL CPPACP 56.685 * 2.379.000 50.178 63.193 CPP-ACP+ 38.769 * 2.379.000 32.261 45.276 NOVAMIN 15.006 * 2.379.000 8.498 21.514 Graph 1: Mean microhardness Recovery in all experimental groups Graph 2: Representation of the study for assessment of Enamel Microhardness Recovery Endodontology, December 2015;27(2):113-117 115
Results There was highly significant difference between mean values of % microhardness when compared as Group I v/s II, III, IV and Group II v/s III, IV, and Group III v/s IV (i.e. p<0.00001). NovaMin with Fluoride performed the best followed by NovaMin, CPP-ACP with Fluoride & CPP-ACP. NovaMin groups had the maximum microhardness recovery (group III- 60.55±7.16, groupiv- 75.56±7.32). (Graph 1 and Graph 2) Discussion The study was done on the Enamel slabs prepared from extracted tooth. The remineralization potential of these remineralizing agents was evaluated by microhardness recovery of enamel. Use of intraoral models in the experiments provides for an understanding of pharmacokinetic behavior of various remineralizing agents. Secondly, they provide the best simulation of the complex system of Enamel, Plaque, and Saliva. So, the appliances incorporating Enamel specimens were made to be worn on the lingual surface of the mandibular arch of the volunteers. Onto the fitting surface of the device, prepared enamel specimens were mounted in recessed areas so as to lie just beneath the lingual aspect of the mandibular premolars. Following remineralization procedure for different groups, each enamel specimen was subjected to microhardness testing. From the data available, percentage microhardness levels were calculated. In the present study there was a highly significant difference between mean values of % microhardness when compared as Group I v/s II, III, IV and Group II v/s III, IV, and Group III v/s IV (i.e. p<0.00001). NovaMin+Fluoride combination performed the best followed by NovaMin, CPP-ACP+Fluoride and CPP-ACP. NovaMin groups had the maximum microhardness recovery (group III- 60.55±7.16, groupiv- 75.56±7.32). Our results coincided with the manufacturer claims and that Novamin and fluoride composition performed the best. These findings were in agreement with that of Alaudin and Fontana 9 who found marked decrease in lesion depth. In disagreement with these findings, Wefel 10 compared fluoride containing Novamin products and opined that when calcium and phosphorous are used in conjunction with topical fluorides, their low solubility could lead to precipitation of these ions, which in turn could make it more difficult for these ions to reach the tooth surface. One of the differences between our study and Wefel s is that we used Stannous Fluoride instead of MFP fluoride (Monofluoro phosphate) fluoride. CPP-ACP performance was less than what was previously expected. Fluoride containing CPP- ACP performed better than CPP-ACP alone. Several studies have confirmed Synergistic remineralizing Effect of addition of Fluoride on Enamel remineralization potential of potential of the fluoride with CPP-ACP. 11-13 This might be attributed to a multitude of reasons, one of which is the formation of amorphous calcium fluoride phosphate ions at the enamel surface. At the same time, it must be recognized that the precipitate formed by the CPP method is not apatite, but a component of tooth and bone, dicalcium phosphate dehydrate (DCPD). Fluoride was found to enhance the conversion of DCPD to Hydroxyapatite. The inferior performance of CPP-ACP based products can be due to the short period in which the study was conducted. Long term studies have to be conducted to evaluate the effect of CPP-ACP. Similarly with Novamin, the basic mechanism is its superior bioadherence to the dentin or enamel surface and converting hydroxyapatite into a crystalline, hydroxycarbonate apatite (HCA) layer which offers protection from acid attack. Addition of fluoride further enhances its potential for remineralization by increasing acid resistance. 11-13 Thus, in the present study it is recommended that treatment with Novamin and Novamin- Fluoride combination is better than other treatment groups under study. Conclusion Effective implementation of remineralizing concepts into clinical practice requires early detection of incipient lesions and timely intervention to allow body s inherent potential of healing. A plethora of products are available in the dental market that claims remineralization of initial carious lesions. This study concluded that Novamin based products yield better results than CPP-ACP based products and that addition of Fluoride to either of these has a synergistic effect on remineralizing potential of these materials. Further in-vivo research is warranted in relation to establishing remineralizing potential of the various remineralizing agents for formulating a clinical recommendation for their use. References: 1. Magitot E. Therapeutic indications in dental caries. 1886 Br. J Dent Sci.29:405-410. 2. Featherstone JD; Caries prevention and reversal based on the caries balance. Pediatr Dent 2006a; 28: 128-132. 3. Rima Wazen and Antonio Nanci. 2003 Repair and regeneration of oral tissues.337-353: In Oral histology Ten Cate s oral histology: development, structure, and function (6 th ed. / Antonio Nanci). Mosby, St. Louis, Mo.: [London], 2003. 4. H Ehlrich et al. / micron 39. 2008.1062-1091.Principles of demineralization: Modern strategies for the isolation of organic frameworks. Part I: Common definitions and History. 5. Torrado A, Valiente M, Zhang W, Li Y, Munos CA. 2004. J.Contemporary Dent. Prac.5: 018-030. 6. Pulido MT, Wefel JS, Hernandez MM, Denehy GE, Chalmers JM, Qian F, et al. The inhibitory effect of MI paste, Fluoride and a combination of both on the Endodontology, December 2015;27(2):113-117 116
progression of artificial caries like lesions in enamel. Oper Dent 2008; 33:550-5. 7. Creanor SL, Strang R, Telfer S, MacDonald I, Smith MJ, Stephen KW. In situ appliance for the investigation of enamel demineralisation and remineralization. Caries Res. 1986; 20: p. 385-391. 8. Lata S, Varghese N O, Varughese JM. Remineralization potential of fluoride and amorphous calcium phosphate-casein phospho peptide on enamel lesions: An in vitro comparative evaluation. J Conserv Dent 2010; 13: 42-6. 9. Allaudin SS, Fontana M.. Evaluation of Novamin as an adjunct to fluoride for caries lesion remineralization. Novamin Research Report. ; 2006. 10. Wefel, JS. NovaMin: Likely Clinical Success. Adv.Dent.Res. 21-40; 2009. 11. T. Suge, K. Ishikawa, A. Kawasaki, M. Yoshiyama, K. Asaoka, and S. Ebisu. Effects of fluoride on the calcium phosphate precipitation method for dentinal tubule occlusion. J. Dent. Res. 1995; 74(4): p. 1079 1085. 12. Anora Burwell. Tubule occlusion of Novamin containing dentifrice compared to Recaldent containing dentrifice- a Remin/ Demin study in vitro Novamin Research Report. ; 2006. 13. E. C. Reynolds, F. Cai, N. J. Cochrane, P. Shen, G. D. Walker, M. V. Morgan, and C. Reynolds. Fluoride and casein phosphopeptide amorphous calcium phosphate. J. Dent. Res. 2008; 87(4): p. 344 348. Effect of addition of Fluoride on Enamel remineralization potential of Endodontology, December 2015;27(2):113-117 117