The Effect of Chlorhexidine on Bacterial Contamination of Hall Technique Elastomeric Orthodontic Separators and Gingival Health: A Pilot Study


  • Nada AlNoman
  • Manal Al Halabi
  • Mawlood Kowash
  • Amar H. Khamis
  • Anas Salami
  • Abiola Senok
  • Rania Nassar
  • Iyad Hussein


Orthodontics, Microbiology, Chlorhexidine


Objective: To study the effect of chlorhexidine on elastomeric orthodontic separators (EOS) bacterial-colonisation and gingival-health in Hall technique (HT) patients. Material and Methods: Prospective in-vivo pilot clinical study of EOS bacterial colonisation and primary-molar gingival health assessment in 20 patients (mean age 5.45±1.27 years) requiring bilateral HT crowns (40 teeth). One side received 1-minute 0.12% chlorhexidine-soaked-EOSs (Chx-EOSs), and the other side dry-EOSs (NoChx-EOSs). The EOSs were removed five-days later and underwent a bacterial enumeration technique. Plaque (PI) and Gingival (GI) indices were assessed pre-, five-days and three-months post-treatment. Wilcoxon-Signed-Rank/McNemar-Chi-square statistics were used (p<0.05). Results: Baseline unused/packaged EOSs’ sterility check yielded zero colony-forming-units (CFU) per millilitre, but 100% of the used EOSs became colonised by oral-microorganisms. An overall trend of lower mean CFU count in Chx-EOSs (3.415± 0.78 x105 CFU/ml) compared to NoChx-EOSs (6.157±1.48 x105 CFU/ml) was observed (p=0.009). Both NoChx-EOSs and Chx-EOSs insertion sites showed evidence of gingivitis with no difference between PI and GI indices by site over time. Conclusion:There was a lower trend of bacterial colonization in chlorhexidine treated EOSs and an occurrence of gingivitis pre/post HT-treatment regardless of EOS type. The lack of difference in the gingival health may be inconclusive due to this pilot’s low power suggesting the need for robust large scale studies.


Innes NP, Evans DJ, Stirrups DR. The Hall Technique; a randomized controlled clinical trial of a novel method of managing carious primary molars in general dental practice: acceptability of the technique and outcomes at 23 months. BMC Oral Health 2007; 7:18.

Hussein I, Al Halabi M, Kowash M, Salami A, Ouatik N, Yang YM, et al. Use of the Hall technique by specialist paediatric dentists: a global perspective. Br Dent J 2020; 228(1):33-8.

SDCEP. Prevention and Management of Dental Caries in Children 2018. Available from: [Accessed on May 14, 2022].

Vishwanath AE, Sharmada BK, Pai SS, Nandini N, Roopa T. Tooth separation potential problems. Int J Orthod Milwaukee 2014; 25(1):35-7.

Becker T, Neronov A. Orthodontic elastic separator-induced periodontal abscess: a case report. Case Rep Dent 2012; 2012:463903.

Malagan MA, PP B, Muddaiah S, Reddy R, Shetty BK, Preetham J, et al. Comparison between efficacy of four different types of orthodontic separators. J Clin Diagn Res 2014; 8(8):ZC41-4.

Rimmer PA, Pitts NB. Temporary elective tooth separation as a diagnostic aid in general dental practice. Br Dent J 1990; 169(3-4):87-92.

Farronato G, Giannini L, Galbiati G, Cannalire P, Martinelli G, Tubertini I, et al. Oral tissues and orthodontic treatment: common side effects. Minerva Stomatol 2013; 62(11-12):431-46.

Umeh OD, Sanu OO, Utomi IL, Nwaokorie FO. Prevalence and intensity of bacteraemia following orthodontic procedures. Int Orthod 2016; 14(1):80-94.

Pithon MM, Ferraz CS, Rosa FC, Rosa LP. Sterilizing elastomeric chains without losing mechanical properties. Is it possible? Dental Press J Orthod 2015; 20(3):96-100.

Rembowski Casaccia G, Gomes JC, Alviano DS, de Oliveira Ruellas AC, Sant' Anna EF. Microbiological evaluation of elastomeric chains. Angle Orthod 2007; 77(5):890-3.

Walker CB. Microbiological effects of mouthrinses containing antimicrobials. J Clin Periodontol 1988; 15(8):499-505.

Nelson Filho P, Macari S, Faria G, Assed S, Ito IY. Microbial contamination of toothbrushes and their decontamination. Pediatr Dent 2000; 22(5):381-4.

Arunachalam LT, Merugu S, Sudhakar U. Comparison of intraoral distribution of two commercially available chlorhexidine mouthrinses with and without alcohol at three different rinsing periods. J Int Soc Prev Community Dent 2012; 2(1):20-4.

Erverdi N, Acar A, Işgüden B, Kadir T. Investigation of bacteremia after orthodontic banding and debanding following chlorhexidine mouth wash application. Angle Orthod 2001; 71(3):190-4.<0190:IOBAOB>2.0.CO;2

Gupta N, Bhat M. Comparative evaluation of 0.2 percent chlorhexidine and magnetized water as a mouth rinse on Streptococcus mutans in children. Int J Clin Pediatr Dent 2011; 4(3):190-4.

Tomas I, Cousido MC, Garcia-Caballero L, Rubido S, Limeres J, Diz P. Substantivity of a single chlorhexidine mouthwash on salivary flora: influence of intrinsic and extrinsic factors. J Dent 2010; 38(7):541-6.

Pithon MM, Santana DA, Sousa KH, Farias IM. Does chlorhexidine in different formulations interfere with the force of orthodontic elastics? Angle Orthod 2013; 83(2):313-8.

El-Patal MA, Asiry MA, AlShahrani I, El Bayoumy SY, Ahmed Wakwak MA, Mohamed Khalil MA. The effect of fiber-reinforced composite versus band and loop space maintainers on oral Lactobacillus acidophilus and Streptococcus mutans levels in saliva. J Indian Soc Pedod Prev Dent 2018; 36(3):301-7.

Omidkhoda M, Rashed R, Bagheri Z, Ghazvini K, Shafaee H. Comparison of three different sterilization and disinfection methods on orthodontic markers. J Orthod Sci 2016; 5(1):14-7.

Loe H. The gingival index, the plaque index, and the retention index systems. J Periodontol 1967; 38(6):Suppl:610-6.

Yilmaz Y, Kara NB, Yilmaz A, Sahin H. Wear and repair of stainless steel crowns. Eur J Paediatr Dent 2011; 12(1):25-30.

Lima RA, Carvalho CB, Ribeiro TR, Fonteles CS. Antimicrobial efficacy of chlorhexidine and calcium hydroxide/camphorated paramonochlorophenol on infected primary molars: a split-mouth randomized clinical trial. Quintessence Int 2013; 44(2):113-22.

Olsen CH. Review of the use of statistics in infection and immunity. Infect Immun 2003; 71(12):6689-92.

Abu Serdaneh S, AlHalabi M, Kowash M, Macefield V, Khamis AH, Salami A, et al. Hall technique crowns and children's masseter muscle activity: A surface electromyography pilot study. Int J Paediatr Dent 2020; 30(3):303-13.

Barker CS, Soro V, Dymock D, Sandy JR, Ireland AJ. Microbial contamination of "as received" and "clinic exposed" orthodontic materials. Am J Orthod Dentofacial Orthop 2013; 143(3):317-23.

Batra P, Jyothikiran H. Tips for maintaining sterilization in your orthodontic work station. Int J Orthod Milwaukee 2014; 25(2):21-30.

Baca P, Junco P, Arias-Moliz MT, Castillo F, Rodríguez-Archilla A, Ferrer-Luque CM. Antimicrobial substantivity over time of chlorhexidine and cetrimide. J Endod 2012; 38(7):927-30.

Omidkhoda M, Rashed R, Khodarahmi N. Evaluation of the effects of three different mouthwashes on the force decay of orthodontic chains. Dent Res J (Isfahan) 2015; 12(4):348-52.

Vivek Aithal PR, Akshai Shetty KR, Dinesh MR, Amarnath BC, Prashanth CS, Roopak MD. In vitro evaluation of microbial contamination and the disinfecting efficacy of chlorhexidine on orthodontic brackets. Prog Orthod 2019; 20(1):17.

Elamin F, Abdelazeem N, Salah I, Mirghani Y, Wong F. A randomized clinical trial comparing Hall vs conventional technique in placing preformed metal crowns from Sudan. PLoS One 2019; 14(6):e0217740.

Pitts NB, Zero DT, Marsh PD, Ekstrand K, Weintraub JA, Ramos-Gomez F, et al. Dental caries. Nat Rev Dis Primer 2017; 3:17030.

Al Anouti F, Abboud M, Papandreou D, Haidar S, Mahboub N, Rizk R. Oral health of children and adolescents in the United Arab Emirates: a systematic review of the past decade. Front Oral Health 2021; 2:744328.

Charan G JM, Mason C, Devalla U. Can orthodontic separators create space for preformed metal crowns in one day? Int J Paediatr Dent 2016; 26 (Supp 1):2-11.

Singh H, Kapoor P, Dhillon J, Kaur M. Evaluation of three different concentrations of chlorhexidine for their substantivity to human dentin. Indian J Dent 2014; 5(4):199-201.




How to Cite

AlNoman, N., Al Halabi, M., Kowash, M., Khamis, A. H., Salami, A., Senok, A., Nassar, R., & Hussein, I. (2023). The Effect of Chlorhexidine on Bacterial Contamination of Hall Technique Elastomeric Orthodontic Separators and Gingival Health: A Pilot Study. Pesquisa Brasileira Em Odontopediatria E Clínica Integrada, 23, e220069. Retrieved from



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