Selective caries removal: After a short time, the 7-year-old boy no longer cooperated and considerable proportions of the carious tooth substance had to be left.
For readers in a hurry
- When excavating, the pulp should not be opened if possible.
- Softened dentin may be left near the pulp (selective excavation), contraindication is irreversible pulpitis.
- If there is no cooperation, carious tooth substance can even be left completely and sealed with steel crowns (Hall technique).
- Contraindications here are caries profunda, irreversible pulpitis or periodontal involvement.
- If the crown pulp is opened during excavation, direct capping or pulpotomies are promising.
Milk teeth, not least molars, should be preserved until the change of teeth. There are several promising methods, some of which do not require excavation at all.
There is a growing consensus that excavation to probe clashing unnecessarily endangers the survival of symptom-free teeth . In the case of deep caries, the pulp is opened too often. In these cases, caries-softened dentin should only be completely removed in the area of the cavity margin and the enamel-cement interface (selective excavation) . In the case of less advanced caries up to the middle dentine penetration agent, on the other hand, complete excavation continues – for a good prognosis of the restoration .
These recommendations apply to permanent teeth, but also to deeply carious, clinically symptom-free milk teeth [1, 3]. Here, too, caries should be removed selectively according to the procedure described above, i.e. only in the marginal area. In the area near the pulp, soft dentin may be left behind – even under the final restoration. As in the case of permanent teeth, it is important to close the restoration tightly and as adhesively as possible. A two-stage therapy (step-by-step excavation) is not recommended for milk teeth [1, 4].
At the next appointment, only minimal mesial and distal preparation was performed and a prefabricated steel crown was inserted with medical Portland cement (Medcem).
Alternative: Hall technology
With the Hall technique, it is even possible to completely dispense with excavation. Here, a prefabricated steel crown is fixed with glass ionomer cement without previous anesthesia and preparation . According to the results of a controlled study, the method is superior to conventional treatment with complete excavation and filling therapy . Whereas the latter showed irreversible pulpitids, loss of vitality, abscesses or a secondary caries that could no longer be restored in 17 percent of the teeth after up to five years, the Hall technique showed a rate of 2 percent.
In contrast, a more recent study after one year showed no significant differences with regard to severe follow-up symptoms (0 percent for Hall technique, 2 percent for selective excavation, 3 percent for complete excavation) . Also with regard to selective excavation, not all studies show advantages over conventional excavation. For example, milk teeth of children treated under anaesthesia for extensive carious defects had success rates of less than 50 percent (after three years) for both methods . The authors assume the high caries activity to be the reason for the comparatively unfavourable results.
Pulpotomy or capping?
Selective excavation shows better results than pulpotomy after systematic literature evaluation . If the pulp is still opened during excavation due to conventional excavation technique or unintentionally, the diagnosis should be as exact as possible . Direct capping is only indicated for teeth without symptoms. The blood must be bright red at the punctiform exposed pulp site and must not bleed spontaneously. For example, MTA (medical Portland cement) or calcium silicate  is suitable as capping material.
Pulpotomies are only indicated for partial pulpitis. No spontaneous or persistent pain must have occurred prior to treatment. An x-ray may indicate periodontal involvement. MTA appears to have advantages over other preparations, iron sulphate is suitable for haemostasis [12, 13].
root canal treatment
Root canal treatment can also be useful for irreversibly infected milk teeth. Root formation should already be complete, but resorption for the permanent replacement tooth has not yet begun. Furthermore, there should be no periapical or interradicular periodontal changes . The treatment is similar to that of permanent teeth with X-ray diagnosis and length determination.
Rinsing and disinfection take place up to the apical third of the root, filling with absorbable pastes , for example calcium hydroxide-iodoform. WK treatments may also be indicated for non-applied permanent teeth. The alveolar ridge can thus be preserved, for example until implantation. If a milk molar can no longer be saved, molar bands are available as a last resort to keep the gap to the first permanent molar open.
Discussion and outlook
In the case of larger carious defects, selective excavation is usually indicated; prefabricated steel crowns have the best restorative prognosis. In uncooperative patients, the Hall technique, a combination of the two methods mentioned above, is suitable if the symptoms are appropriate. The prerequisite is always a good diagnosis, which requires care and experience.
There can be problems with children with high caries activity. This is further evidence that the virulence of the microbial community in the biofilm is an important risk factor. As the literature shows, crowns have advantages over fillings. If still possible and reasonable, milk teeth can also be preserved with capping, pulpotomies or root canal treatments.
1. Schwendicke F et al. Adv Dent Res 2016. 28 (2): 58-67. 2. Innes, N. P., et al.; Adv Dent Res 2016. 28 (2): 49-57. 3. Santamaria R et al. Evid Based Dent 2014. 15 (3): 81-82. 4. Lula, E. C.., et al.; Caries Res 2009. 43 (5): 354-358. 5. Innes N P et al. BMC Oral Health 2007. 7 18. 6. Innes N P et al. J Dent Res 2011. 90 (12): 1405-1410. 7. Santamaria R M et al. J Dent Res 2014. 93 (11): 1062-1069. 8. Melgar X C et al. Caries Res 2017. 51 (5): 466-474. 9. Smail-Faugeron V et al. Eur J Paediatr Dent 2016. 17 (2): 107-112. 10. Pabel S O et al. Bayerisches Zahnärzte Blatt BZB 2016 (May): 57-65. 11. Schwendicke F et al. Clin Oral Investig 2016. 20 (6): 1121-1132. 12. Asgary S et al. J Clin Pediatr Dent 2014. 39 (1): 1-8. 13. Stringhini Junior E et al. Eur Arch Paediatr Dent 2015. 16 (4): 303-312. 14. Rodd H D et al. Int J Paediatr Dent 2006. 16. Suppl 1 15-23.
Dr. Jan H. Koch
Dr. med. dent. Jan Hermann Koch has been working as a freelance journalist and consultant since 2000. His work focuses on specialist articles, press releases and media concepts for the dental industry and associations. Since 2013, Dr. Koch has been a permanent freelancer for DZW and trade magazines, including the column ZahnMedizin kompakt (successor to Dr. Karlheinz Kimmel).