A clinical report. Water-free stannous-fluoride gel and post-irradiation caries

PREVENTING CARIES AFTER RADIOTHERAPY TO THE HEAD AND NECK REGION - A SYSTEMATIC REVIEW

OBJECTIVES

Radiotherapy to the head and neck region (HN) bears the risk of a rampant development of caries, making intensified prevention necessary. Aim of this systematic review was to summarize the evidence on the efficacy of caries preventive measures in these patients.

METHODS

Clinical studies investigating caries in patients with radiotherapy in the HN with at least 1 caries preventive intervention compared to any control were included. Reports in languages other than English or German were excluded. Records were identified on PubMed, Web of Science, Google Scholar, and Cochrane Library mid-January 2024. Risk of bias was assessed with RoB2. Results were summarized. Planned meta-analyses could not be performed, because of heterogenous data.

RESULTS

Five studies were included, with a total of 355 participants. They were irradiated with up to 70 Gy and received different caries preventive interventions, including sodium fluoride or stannous fluoride gels, remineralizing solutions, an "Intraoral Fluoride Release System" and sucrose restricted diet. Caries score increased between 0.48 DMF-S and 9.2 DF-S per year. Largest differences in caries increments were measured between groups with insufficient and with rigorous fluoride application.

CONCLUSIONS

The main limitations were compromised randomization, heterogeneity of patients and small sample sizes. Clinical studies on caries prevention after radiotherapy to the HN are lacking and the existing ones bear extensive limitations. However, the large effect size and broad consensus suggest the use of fluoride to be indispensable in preventing caries in these patients. The study was funded by the Medical Center - University of Freiburg and was not registered.

Prosthetic rehabilitation of defects of the head and neck

Patients afflicted with head and neck cancer, traumatic injuries to the head and neck, or those with congenital or developmental defects benefit from multidisciplinary team management. The head and neck region participates in complex physiologic processes that can often be impeded by these circumstances. Evaluation of the patient by the maxillofacial prosthodontist can assist the other members of the team in providing treatment planning options for the patients. Intraoral defects arising from these circumstances can be treated with prosthodontics that serve to assist with speech, swallowing, and to some degree mastication. If chemotherapeutic or radiation modalities are also used to treat the head and neck, assessment of the patient by the maxillofacial prosthodontist may prove to identify factors that may predispose to undesirable sequelae. Preventive treatment by elective tooth extraction, prosthodontic assessment, and patient education prove to assist in predictable management of these oftentimes complex presenting conditions. Facial defects arising from similar circumstances can be an alternative or adjunct to plastic surgical reconstruction and offer the added advantage of tumor surveillance in susceptible patients.

A critique of topical fluoride methods (dentifrices, mouthrinses, operator-, and self-applied gels) in an era of decreased caries and increased fluorosis prevalence

Within the last 20 years there has been a decrease in the caries prevalence of US schoolchildren, a change in the intraoral caries pattern, and a slowing of the progress of lesions. Simultaneously, the prevalence of enamel milder, cosmetically acceptable forms and is more noticeable in fluoride-deficient communities than those with optimal or above-optimal water fluoride concentrations. Circumstantial evidence indicates that a principal contributor to the caries decline is the extensive use of fluoride dentifrices. Conversely, although use of a fluoride dentifrice can add to the total daily amount of ingested fluoride in preschool children, there is little evidence to suggest that dentifrice ingestion is a principal factor causing the fluorosis increase. The value of fluoride methods may be assessed in relative or absolute terms. The relative, or percentage, caries reduction attributed to fluoride mouthrinses and gels appears to be a property intrinsic to the methods themselves and generally is little affected by the caries activity of the population being treated. Conversely, the absolute, or numerical, caries reduction is dependent upon the level of disease in the population. Thus, the reported caries decline reduces the number of surfaces prevented from developing caries, even though the percentage reduction remains substantially unchanged. Although inadvertent ingestion of fluoride can result from the use of mouthrinses and gels, there is little evidence to suggest that they have contributed to the fluorosis increase. When using topical methods, prudence should prevail to avoid ingestion of fluoride. Fluoride dentifrices should continue to be used routinely, and although lower potency dentifrices may be considered, the literature does not provide strong support for their need. Use of fluoride mouthrinses and gels for individual patients should be predicted upon their caries activity or risk. Use of these methods in public health programs is a matter of cost-effectiveness, which will be influenced by the caries prevalence of the target population.

Review of the anticaries effectiveness of professionally applied and self-applied topical fluoride gels

Of the five types of topical fluoride gel products available in the United States, two have not been clinically tested in randomized double blind clinical trials. For those tested, the averaged results of clinical trials involving schoolchildren in fluoride-deficient communities indicate a caries reduction of approximately 26 percent from either a professional or self-administered program. A similar relative reduction can be expected from programs conducted in fluoridated communities, but the absolute caries inhibition is less. Twice-a-year professional applications are more effective than once-a-year applications, and self-applications using trays are more effective than applying the gel on a toothbrush. For subjects beyond school age, there are few clinical studies of either self-applied or professionally applied gels; however, current epidemiological evidence does not indicate a need for public health caries preventive programs for healthy employed adults. For medically compromised patients, especially those exhibiting rampant caries associated with radiation-induced xerostomia, a variety of topical gel procedures appear to be effective in limiting caries.

Nonimmunologic aspects of caries resistance

A variety of components provide salivary secretions with an array of potentially effective means of combating cariogenic challenges. These defense factors range from a laissez-faire mechanical cleansing to exquisitely controlled production of highly specific antibodies. In between the two extremes are antibacterial systems whose operating characteristics are only beginning to be understood. These systems are well worth our attention. They may be the key to our understanding of variations in individual susceptibility, and could provide valuable leads for development of anticaries agents.

Chemical protection against postirradiation dental caries

Experience with dental caries in twenty-four patients receiving irradiation for malignant lesions of the head and neck demonstrates the critical importance of cooperation by the patient, a program of strict oral hygiene, and daily self-treatment with 0.4 per cent stannous fluoride gel. The ravaging form of dental caries associated with the postirradiation period can be essentially eliminated in cooperating patients. In nine patients who were uncooperative, fifty-seven crowns were amputated and an additional seventy-five carious surfaces were found 3.75 years after irradiation. In six patients who cooperated and used the gel on a daily basis, no crowns were amputated and only one carious area was found over the same time period.