The Hall Technique by Dr. Jeanette MacLean

Dentaltown Magazine

A minimally invasive method of treating caries in pediatric patients

by Dr. Jeanette MacLean

A shift to minimally invasive treatment

It’s now known that caries is a biofilm disease, and carious lesions are the result of a dysbiosis (an imbalance in the biofilm) whereby net demineralization exceeds remineralization—and surgical intervention alone does not stop the disease process.

Systematic reviews and meta-analyses demonstrate that complete caries removal is not necessary for caries management in an otherwise healthy, asymptomatic tooth. Instead, controlling the biofilm and placing a sealed restoration is preferred for caries management. This minimally invasive approach is particularly advantageous for young, apprehensive patients, who may otherwise require sedation for traditional surgical interventions. An evidence-based, minimally invasive treatment option for the management of severe early childhood caries is the Hall technique.

The Hall technique

Dr. Norna Hall was a general practice dentist working in a region with a high level of caries in Scotland. In 1997, an audit discovered she was placing stainless steel crowns at a higher-than-average rate. Hall also was placing them in an unconventional way—without local anesthesia or tooth preparation, simply sealing the carious lesions under the crown with a glass ionomer cement, thereby cutting them off from their “fuel” (i.e., dietary carbohydrates) and arresting them.

To her surprise and delight, the clinical outcomes were similar to conventional crown placement and well accepted by her patient population.1 And so the Hall technique was born. Since that time, four randomized control trials have been published that demonstrate the efficacy of the Hall technique for caries management in pediatric patients.2–5

Presenting to the parent

When introducing the option of the Hall technique to a parent, I say this: “What would happen to you if I dropped you in a tank of cement? Would you live or would you die?” I usually get a look of wide eyes, followed by a laugh, then a response, “Die.”

To which I reply, “Correct. So, when I seal the cavities’ bugs under a crown in cement, they’re also starved of the fuel needed to survive, and they arrest and die.”

I also explain that the efficacy for the Hall technique is equivalent to the traditional surgical, i.e., drill-and-fill approach, each with a small margin of failure.6 However, the Hall technique has an added benefit in that it eliminates the need for shots and drills, which could require sedation for their child to tolerate the treatment. With proper informed consent, I have found the technique is well accepted by parents and well tolerated by patients.


• Clinical symptoms of irreversible pulpitis or dental abscess.

• No clear band of dentin between the carious lesion and the pulp.

• Radiographic evidence of pulpal exposure or periradicular pathology.

• Unrestorable, inadequate tooth structure for crown retention.

• Children whose airway cannot be managed safely.


• Patient-centered care.

• Quicker to complete.

• Proven efficacy by randomized control trials.

• Minimal intervention is favorable to the pulp.

• Reduced anxiety/stress for the child patient, parent and dentist.

• No need for local anesthetic or tooth preparation.

• No soft-tissue damage.

• No accidental lip or tongue biting.

Case presentation

A 5-year-old girl presents with extensive yet asymptomatic caries in her mandibular left first primary molar (Fig. 1).

Informed consent is reviewed with the patient’s mother and treatment options were discussed, including no treatment; silver diamine fluoride; extraction; or a prefabricated stainless steel crown, placed with either traditional surgical preparation or the noninvasive Hall technique.

The patient’s mother opted for the Hall technique because it would involve minimal tooth preparation and no need for local anesthetic or sedation.

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The technique

Place orthodontic separators into the mesial and distal contacts to create space for the crown. You may use orthodontic pliers, or thread two pieces of floss through the separator, pull them in opposite directions to stretch the band, and then slide it into the contact. If the patient has open contacts or primate space, it may not be necessary to place separators (Figs. 2a–2d).

After approximately two days to one week, remove the separators and clean gross debris with plain pumice, then rinse (Figs. 3a, 3b and 4).

Protect the patient’s airway by positioning the child slightly upward, drape a 4x4 gauze across the back of the throat, and/or use a rolled piece of adhesive medical tape to adhere the SSC to your gloved finger.

Select the crown and crimp or adjust as needed to have a “snap” fit and good marginal adaptation (Figs. 5a–c).

Fill the crown with a high-quality glass ionomer or resin-modified glass ionomer cement (Figs. 6a–6c).

Seat the crown with firm finger pressure, or use a bite stick and have the patient help by biting down firmly on a cotton roll (Fig. 7).

Clean the excess cement with wet gauze, water spray and flossing the contacts (Figs. 8a and 8b).

The patient’s bite may be slightly opened by approximately 1mm and will self-adjust over the next one to two weeks via intrusion of the crowned tooth and opposing tooth, as well as supereruption of the adjacent teeth7–8 (Figs. 9 and 10a–10c).

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The controversy

There remains some controversy regarding this technique in the U.S., often stemming from lack of awareness of the randomized control trial evidence for Hall crowns or the systematic reviews and meta-analyses that have demonstrated that complete caries removal is not necessary for caries management.9–10 Members of the International Caries Consensus Collaboration, Drs. Innes, Frencken and Schwendicke, summed it up best in their 2016 article:

“The failure to follow new evidence is not limited to dentists who are ‘out of touch,’ do not undertake continuing professional development, or have been practicing for many years; in some countries and some schools, new dentists are still taught to remove all infected carious tissue, and it is actually not possible to pass professional examinations without demonstrating this. The reasons underlying this failure to translate evidence into clinical practice are many and complex.

“The ‘don’t know’ could be due to general ignorance (perhaps remedied with an appropriate educational intervention) or the more problematic willful ignorance, where the subject chooses not to learn more about a topic (perhaps because it challenges his or her current beliefs).”11

The big picture

While the Hall technique is not for every patient nor every tooth, it is an evidence-based procedure that is an extremely advantageous option for managing severe early childhood caries. This minimally invasive approach allows the provider to increase access to care and improve the patient experience while reducing cost and risk.

1. Innes NP, et al. The Hall Technique 10 years on: Questions and answers. Br Dent J. 2017 Mar 24;222(6):478-483. doi: 10.1038/sj.bdj.2017.273.
2. Innes N P, Evans D J P, Stirrups DR. Sealing caries in primary molars; randomized control trial, 5 year results. J Dent Res 2011; 90: 1405-1410.
3. Santamaria R M, Innes N P T, Machiulskiene V, Evans D J P, Splieth C H. Caries management strategies for primary molars: 1yr randomized control trial results. J Dent Res 2014; 93: 1062–1069.
4. Narbutaite J, Maciulskiene V, Splieth C H, Innes N P T, Santamaria R M. Acceptability of three different caries treatment methods for primary molars among Lithuanian children. 12th Congress of the European Academy of Paediatric Dentistry ‘A passion for Paediatric Dentistry’
5. Araujo MP, Olegario IC, Hesse D, Innes NP, Bonifacio CC, Raggio DP. ART versus Hall Technique in Primary Molars: 1-Year Survival and Cost Analysis of a RCT ORCA Abstract number 86. Caries Res 2017;51:330 DOI: 10.1159/000471777
6. Ludvig KH, Fontana M, Vinson L A, Platt J A, Dean J A. The success of stainless steel crowns placed with the Hall Technique. JADA 2014; 145: 1248-1253.
7. Van der Zee V, van Amerongen W E. Influence of preformed metal crowns (Hall Technique) on the occlusal vertical dimension in the primary dentition. Eur Arch Pediatr Dent 2010; 11: 225-227.
8. So D, Evans D J P, Borrie F et al, Measurement of Occlusal Equilibration Following Hall Crown Placement. J Dent Res 2015; 94 (Spec Iss A). Abstract No 0080; 2015. IADR, Boston, US.
9. Thompson V., et al. Treatment of deep carious lesions by complete excavation or partial removal: a critical review. J Am Dent Assoc. 2008 Jun;139(6):705-12.
10. Ricketts D., et al. Operative caries management in adults and children. Cochrane Database Syst Rev. 2013 Mar 28;(3).
11. Innes N., et al. Don’t Know, Can’t Do, Won’t Change: Barriers to Moving Knowledge to Action in Managing the Carious Lesion. J Dent Res 2016; May;95(5):485-6.

Author Bio
Author Dentaltown editorial advisory board member Jeanette MacLean, DDS, DABPD, FAAPD, is a board-certified pediatric dentist and private practice owner in Glendale, Arizona. MacLean has become an internationally recognized expert and advocate on the hot topic of minimally invasive dentistry, frequently lecturing across North America. Information:
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