Based on the changing understanding of carious biofilm development and caries progression, Sealing carious dentine beneath a restoration deprives the caries biofilm of nutrients and alters the environment sufficiently to slow or arrest lesion progression. This has the added benefit of avoiding pulp exposure and subsequent treatment .The evidence base supporting the biological approaches which include Hall technique has been steadily increasing in the last few years. This has given rise to a growing trend towards a biological approach by Paediatric dentists and has led to an increasing concern about the merits of conventional approach in treatment of carious primary molars .

In orofacial development of the child, preservation of the primary dentition for as long as possible is of great importance. As primary teeth maintain arch length and preserve masticatory function. Unfortunately, the occurrence of cavitated caries lesions is still a problem in developed and developing countries, with an increasing prevalence, particulary in developing communities, conflicting with a general descending trend in prevalence worldwide.

The management of carious primary molars in children is problematic, additionally, primary teeth commonly remain unrestored, especially in the younger children,The high levels of dental disease in primary teeth, and its inadequate management, remains a major public health issue for children, and one with a significant impact on their lives. In addition many children are having to accept toothache as a part of their childhood. Set against this background, there would seem to be some scope for the investigation of alternative approaches to the management of carious primary teeth. If an alternative technique was found to be simpler and more acceptable to children, their parents and general dental practitioners than the conventional restorative approach, yet just as effective, then it might be more readily applied in the general practice setting.

A novel, simplified method of using stainless steel crwons, the Hall Technique, has been investigated. According to American Academy of Pediatric Dentistry, Hall technique calls for cementation of a Stainless steel crown over a caries-affected primary molar without local anesthetic, caries removal or tooth preparation, This technique was developed for use when delivery of ideal treatment wasn't feasible.

As the crown is fitted with no occlusal reduction in the Hall technique, it was observed in several studies that the occlusion would has been temporarily opened and returned to the pretreatment situation within 2 weeks and no child reported Tempromandibular joint pain. This goes in accordance with the study of Innes et al., as they stated that after placement of stainless steel crowns using the Hall technique, the occlusion returns to the pretreatment situation within 15-30 days. Also, Dr. Hall stated that the occlusion tended to equilibrate by the next recall appointment and none of her patients reported Tempromandibular joint pain.

A published data from Dr Hall's practice records has indicated that Hall technique might have similar survival rates to other, more conventional, restorative options currently being used in Primary Care. In addition, avoiding the use of Local anesthesia and rotary instruments for tooth preparation and caries removal might mean that the technique is less demanding of both children and their dental team. The technique is therefore minimally invasive and can be expected to cause less discomfort than conventional treatment approaches. This aspect could be a considerable advantage as the Hall technique is a child centered approach and it is not surprising that the first data published on patient perceptions of the hall technique are promising. It was reported a clear difference in levels of discomfort, subjectively assessed by the operators, between the Hall technique and a conventional treatment approach. The Hall stainless steel crowns caused 'no discomfort' to 'mild discomfort' in comparison to the conventional restorations. Several conducted studies showed that the majority of the children, their caretakers and dentists expressed a preference for the Hall technique to the conventional restorations.

The Hall Technique embraces changing concepts of managing dental caries, moving from the dogma requiring its complete surgical excision, even at the expense of cavity size and pulpal health, to the understanding that caries in dentine can be slowed, arrested, and possibly even reversed, within a meticulously sealed environment. It is known that the microflora in sealed carious dentine changes, with the predominating organisms no longer being cariogenic having been sealed from the oral environment. This may be important in the apparent arrest of caries progression.

Owing to its non invasive design, acceptance by patients and rate of restoration longevity, the Hall technique maybe an improved treatment option to increase access to care, decrease rates of untreated caries and provide a restoration that will allow for natural tooth exfoliation.

In the last few years, conventional restorations including complete removal of carious tissue with or without pulp therapy for the treatment of carious lesions in primary teeth have been challenged and a more biological approach has been suggested. This has given rise to a growing trend towards a biological approach by paediatric dentists and has led to an increasing concern about the merits of the conventional approach and whether to retain this treatment modality as the standard technique in restoring primary teeth or to adopt the biological approach as the treatment norm.

Inclusion Criteria:

• Children:Aged 5 to 7 years, in good general health and medically free.The parents provided a written informed consent.
• Primary molar with deep dentin caries involving occlusal and or occluso proximal surfaces.
• Vital pulp with absence of clinical signs and symptoms of irreversible pulpitis such as spontaneous pain. Only presence of pain provoked with stimulation, such as complaints of food impaction when eating is allowed.
• Absence of clinical swelling or pus exaudate or fistula of soft or periodontal tissues.
• Absence of abnormal tooth mobility
• Absence of pain on percussion

Exclusion Criteria:

• Patients experience any signs or symptoms of pulpal or periapical pathology.
• Patients with systemic diseases requiring special dental consideration.
• Unmotivated uncooperative patients.
• Patients unable to attend follow up visits.

Study Protocol, Informed consent form, clinical study report

6 months after completion of the study

ClinicalTrials.gov