JADA Continuing Education
Three restorative materials and topical fluoride gel used in xerostomic patients
A clinical comparison
CARL W. HAVEMAN, D.D.S., M.S.,
JAMES B. SUMMITT, D.D.S., M.S.,
JOHN O. BURGESS, D.D.S., M.S. and
KAREN CARLSON, B.S.
 |
ABSTRACT
|
|---|
Background. The authors compare the incidence of recurrent caries around two glass ionomer restorative materials and one amalgam material.
Methods. The authors placed 111 restorations in nine xerostomic patients. Patients were given oral hygiene instructions and fluoride gel to use daily. The authors evaluated the restorations clinically and with photographs and impressions at six months, one year and two years according to criteria for marginal adaptation, anatomical form, caries in adjacent tooth structure and caries at the cavosurface margin. The authors divided patients into users and nonusers of fluoride.
Results. At the two-year recall appointments, the authors evaluated 95 (86 percent) of the 111 restorations. They analyzed two-year data using an analysis of variance for repeated measures and Fisher’s post hoc test. The study results showed no significant differences among materials in regard to caries at the cavosurface margin among fluoride users. However, among fluoride nonusers, patients with amalgam restorations had a significantly higher incidence of caries at the cavosurface margins than did patients with either of the two glass ionomer restorations. The authors found no statistically significant difference between restorations with regard to marginal integrity or anatomical form. However, one patient exhibited failure of glass ionomer restorations owing to material loss.
Conclusions. Less caries developed at the margins of glass ionomer restorations compared with amalgam restorations in xerostomic patients who did not routinely use a neutral topical sodium fluoride gel.
Clinical Implications. Fluoride-releasing materials may reduce caries surrounding restorations in high-risk patients who do not routinely use topical fluoride. Patients who routinely used topical fluoride gel did not develop recurrent caries, and clinicians should encourage the use of fluoride gel on a daily basis.
Xerostomia, or dry mouth, is recognized as having a pronounced adverse effect on the incidence and risk of developing dental caries because of the lost buffering capacity of the saliva, reduced ions needed for remineralization and increased number of cariogenic microorganisms. Although the precise salivary flow rate required to protect teeth has not been determined, an unstimulated flow rate of 0.2 millimeters/minute or less is considered to be below normal by public health researchers.1
Fluoride-releasing materials may reduce caries surrounding restorations in high-risk patients who do not routinely use topical fluoride.
|
BACKGROUND
|
|---|
When asked if they had noticed an increase in the number of patients who have xerostomia, 87 percent of the respondents to The Journal of the American Dental Association’s Question of the Month for August 2001 stated that they had seen increases of 15 to 35 percent during the past couple of years.2 Multiple clinical studies have shown the efficacy of using topical fluoride gel on a daily basis to prevent caries in high-risk patients.3–5 However, there is a paucity of in vivo evidence regarding the effect of fluoride-releasing restorative materials in patients at high risk of developing caries. In vivo studies comparing the daily use of topical fluoride with the effect of fluoride-releasing materials on the incidence of caries in high-risk patients are extremely scarce.
Glass ionomer restorations.
In one two-year clinical study, Wood and colleagues6 found that glass ionomer restorations placed in patients whose compliance with the daily use of a topical fluoride was less than 50 percent had increased longevity compared with amalgam restorations. However, they also found that in patients whose compliance with the daily use of a sodium fluoride gel (pH, 5.8) was more than 50 percent, 32 (91 percent) of 35 glass ionomer restorations failed as a result of surface erosion. There was no recurrent caries associated with these restorations, nor with any of the 35 amalgam restorations placed in patients who used the sodium fluoride gel more than 50 percent of the time.6
Although glass ionomer restorative materials have inferior mechanical properties compared with amalgam and resin-based composite, they bond to tooth structure and release fluoride. The fluoride release begins with an initial burst and rapidly declines to a low-level, slow-release rate. Glass ionomer restorative materials are "rechargeable" in that they take up and re-release fluoride from fluoride-containing agents. The recharging of fluoride-releasing materials may be the most important factor in maintaining cariostatic properties.7–9 Conventional glass ionomers and resin-modified glass ionomers have a well-documented protective effect against tooth demineralization in vitro.7,10–12 Although the exact level of fluoride release required to protect against caries has not been established, a dose-response relationship has been demonstrated for fluoride.13
Conflicting information exists concerning the reduction in recurrent caries rates surrounding glass ionomer restorations in vivo.
Conflicting information and controversy exist concerning the reduction in recurrent caries rates surrounding glass ionomer restorations in vivo.7.14–17 In two surveys of general practitioners, Mjör14,15 reported that the primary reason for the replacement of glass ionomer restorations was recurrent caries and that the recurrent caries rate for teeth restored with glass ionomer restorations was no better than that for teeth restored with resin-based composite. McComb16 conducted a comprehensive literature review of in vivo studies of caries prevention via fluoride-releasing restorative materials and concluded that there is modest evidence of a caries-controlling influence by glass ionomer cements. In a similar review, Randall and Wilson17 found no conclusive evidence of decreased recurrent caries surrounding glass ionomer restorations compared with other materials.
Caries-protective effect.
A significant problem with studies of fluoride-releasing materials is that much of the research evaluating the caries-protective effects of glass ionomer restorations has not focused on patients at high risk of developing caries, such as those with low salivary flow, high Streptococcus mutans counts, or high sucrose intake and poor plaque control. High caries rates are needed in clinical trials that evaluate the efficacy of fluoride-releasing materials to provide a challenge that is severe enough to determine the effectiveness of these materials in reducing the caries incidence. If the caries risk of patients is low or if the sample size is too small to detect a difference in patients with low caries rates, the study will not be able to detect a difference in the recurrent caries rates for teeth restored with fluoride-releasing and non–fluoride-releasing materials.
The purpose of this study was to compare the clinical performance and recurrent caries associated with two fluoride-releasing glass ionomer materials and one non–fluoride-releasing amalgam material used for Class III and V restorations in patients with a low salivary flow rate who were instructed to use a topical fluoride daily. The initial hypothesis for this study was that no difference would be detected in the recurrent caries rates adjacent to fluoride-releasing and non–fluoride-releasing materials in any of the patients.
|
MATERIALS AND METHODS
|
|---|
Three of us (C.H., J.S., J.B.) placed 111 restorations in nine patients classified as xerostomic, based on subjective symptoms and a resting salivary flow rate of less than 0.2 milliliters/minute. The subjects (seven women, two men) were recruited from The University of Texas Health Science Center at San Antonio. We used rubber dam isolation for all restorations. The fluoride-releasing materials used were Ketac-Fil Aplicap (now marketed as Ketac-Fil Plus Aplicap) (3M ESPE, St. Paul, Minn.) and Vitremer Core Buildup/Restorative (3M ESPE). The non–fluoride-releasing material used was Tytin amalgam (Kerr, Orange, Calif.).
We placed and finished the restorations in one appointment in accordance with the manufacturers’ instructions. Tytin restorations were not polished. Ketac-Fil restorations were finished with Sof-Lex discs (3M ESPE) and coated with light-cured unfilled resin (Scotchbond Multi-Purpose Dental Adhesive, 3M ESPE). Vitremer restorations were finished with Sof-Lex discs, but they were not coated with unfilled resin. The choice of restorative material was not entirely random in that amalgam was not placed in the maxillary anterior teeth. Otherwise, we used a coin flip to determine the restorative material to be used.
Two of us (C.H., J.B.) evaluated the restorations at six months, one year and two years using scoring criteria similar to those described by Wood and colleagues6 (see box
). At each evaluation, color slides and polyvinylsiloxane impressions were made to aid in the evaluation process.
At the beginning of the study, we gave patients instructions on oral hygiene and home care that included the daily application of fluoride gel (1.1 percent sodium fluoride, pH 7.0) (PreviDent brush-on gel, Colgate Oral Pharmaceuticals, Canton, Mass.) via a custom-made tray or by brushing it on. We assessed patient compliance with these instructions during the study by recording the amount of fluoride gel used (that is, we recorded the number of tubes dispensed during the study) and at the end of the study by questioning the patient. (Specifically, patients were asked how often they complied with the instructions to use the topical fluoride gel on a daily basis.)
At the completion of the study, we divided the patients into two groups: fluoride users (that is, those who were compliant at least 50 percent of the time) and fluoride nonusers (that is, those who were compliant less than 50 percent of the time).
|
RESULTS
|
|---|
We evaluated 95 (86 percent) of the 111 restorations at the two-year recall appointment (Table 1). Table 2 shows the results expressed as the percentage of restorations with the most favorable rating (score of 0) for each of the rating criteria. As shown in Tables 1 and 2, caries did not develop at the cavosurface margin, or CSM, of 23 (85 percent) of 27 Ketac-Fil restorations, 30 (88 percent) of 34 Vitremer restorations and 19 (56 percent) of 34 Tytin restorations.
All of the restorations with caries at the CSM developed in the three patients who were less than 50 percent compliant with regard to the daily use of fluoride gel. The cumulative findings for restorations with caries at the margin in these patients were as follows: four (36 percent) of 11 Ketac-Fil restorations, four (27 percent) of 15 Vitremer restorations and 15 (68 percent) of 22 Tytin restorations. None of the patients who complied with the daily use of fluoride gel had restorations with caries at the CSM.
We analyzed two-year data using analysis of variance for repeated measures and a Fisher post hoc test. This analysis revealed a significant difference between materials regarding caries at the CSM in patients who were less than 50 percent compliant with the daily use of fluoride gel. Patients with the glass ionomer restorations had a significantly lower rate of caries at the CSM than did patients with amalgam restorations (P < .05). We rejected the hypothesis that no difference would be detected in recurrent caries rates between fluoride-releasing and non–fluoride-releasing materials in any of the patients.
In regard to marginal integrity and anatomical form, we found no statistically significant difference in the clinical success of the three restorative materials at the two-year recall appointment. However, six (86 percent) of the seven glass ionomer restorations (three Ketac-Fil and three Vitremer) placed in a single patient exhibited surfaces that rapidly became severely eroded and partially dissolved. These restorations required replacement between six and 24 months after they were placed. No recurrent caries was associated with any of these seven restorations. None of the other patients experienced a rapid loss of surface material from the glass ionomer restorations.
|
DISCUSSION
|
|---|
Patient no. 6, who had received radiation therapy for head and neck cancer, refused to use the topical fluoride and perform basic oral hygiene. This patient agreed to return to the clinic for the evaluation appointments, but refused to undergo routine care. Figure 1 shows Vitremer restorations in teeth nos. 26 and 27 two years after placement. Although a large amount of caries is present in these teeth, the caries does not involve the margins of the restorations, which indicates a caries-protective effect of the restoration.
View larger version (81K):
[in this window]
[in a new window]
|
Figure 1. Glass ionomer restorations (Vitremer Core Buildup/Restorative, 3M ESPE, St. Paul, Minn.) in teeth nos. 26 and 27 and amalgam restorations (Tytin, Kerr, Orange, Calif.) in teeth nos. 28 and 29 two years after placement in patient no. 6.
| |
Figure 1
also shows amalgam restorations in teeth nos. 28 and 29, with caries involving the margins of both restorations, indicating a lack of caries-protective effect. Caries was present at the margin of one (9 percent) of the 11 fluoride-releasing glass ionomer restorations placed in this patient, whereas caries involving the margins was evident for four (67 percent) of six amalgam restorations.
Patient no. 1 also had received radiation therapy for head and neck cancer and was poorly compliant with regard to the use of fluoride gel (that is, less than 50 percent of the daily applications). This patient refused to stop the frequent daily consumption of a sugar-containing soft drink as the primary means of moistening the mouth. Although we provided repeated instructions in the proper use of fluoride gel and in oral hygiene methods, the patient was poorly compliant and had a high appointment failure rate. Caries was present at the margins of six (54 percent) of 11 glass ionomer restorations and at the margins of 11 (79 percent) of 14 amalgam restorations.
Figure 2 shows a Vitremer restoration in the mesiolingual aspect of tooth no. 7 at baseline in patient no. 1. Figure 3 shows the same restoration 13 months later. Caries was present within 3 mm of the restoration, but did not involve the margin. Figure 4 shows this restoration 17 months after placement. Rapid caries progression has occurred, and the caries adjacent to the Vitremer restoration involved the margin. This sequence of photographs reveals that the cariostatic effect of this fluoride-releasing restorative material is limited and can be overwhelmed by a rapidly progressive caries process.
View larger version (80K):
[in this window]
[in a new window]
|
Figure 2. Glass ionomer restoration (Vitremer Core Buildup/Restorative, 3M ESPE, St. Paul, Minn.) in the mesiolingual aspect of tooth no. 7 at baseline in patient no. 1.
| |
Glass ionomer restorations provided a greater in vivo cariostatic effect than did amalgam restorations in patients at high risk of developing caries.
Glass ionomer restorations provided a greater in vivo cariostatic effect than did amalgam restorations in patients at high risk of developing caries. After two years, four (15 percent) of 27 Ketac-Fil restorations, four (12 percent) of 34 Vitremer restorations and 15 (44 percent) of 34 Tytin restorations were associated with caries at the CSM. These findings are similar to those of Qvist and colleagues,18 who reported that after three years, caries progression in primary teeth involved 21 percent of amalgam restorations compared with 12 percent of glass ionomer restorations.
Our findings also support those of Donly and colleagues,19 who found that resin-modified glass ionomer restorations can help prevent enamel demineralization on adjacent teeth.
It is important to note that the six patients in our study who were at least 50 percent compliant with regard to the daily use of fluoride gel exhibited no caries within 3 mm of the margins of their 47 restorations in all. However, we did not assess the presence of caries elsewhere in the restored teeth or in other teeth. The results of this study support those of Wood and colleagues6 and those of other studies3–5 that demonstrated the efficacy of using topical fluoride gels daily to prevent caries. The primary finding in these studies is that there was a dose-response relationship between fluoride use and caries incidence.
We are concerned about the survivability of glass ionomer restorations in a dry mouth. However, a large majority of the glass ionomer restorations in this study did not experience rapid material failure leading to poor marginal adaptation or poor anatomical form, as did occur in the study by Wood and colleagues.6 Although a small percentage of glass ionomer restorations failed as a result of loss of surface material (three [9 percent] of 32 Ketac-Fil restorations were replaced after six to 12 months and three [9 percent] of 34 Vitremer restorations failed after 12 to 24 months), all of these failures occurred in a single patient (patient no. 7). The rapid surface loss that occurred in these restorations is similar to that seen by Wood and colleagues,6 who reported dissolution of 32 (91 percent) of 35 glass ionomer restorations in patients who used a topical fluoride gel with a pH of 5.8 on a daily basis.
Table 3 shows pertinent data for each patient. Patient no. 7 was severely xerostomic and used the fluoride gel daily. Although it is possible that the fluoride gel contributed to the rapid surface degradation of the glass ionomer materials, this is unlikely because patients 4, 5 and 9 also were very xerostomic and complied with regard to the daily use of fluoride. None of the glass ionomer restorations in these patients exhibited surface degradation.
Table 3 also shows that the resting salivary flow rate of seven (78 percent) of the nine patients was less than 0.1 mL/minute. Researchers have shown that dehydration damages glass ionomer material20,21; however, only patient no. 7 experienced a rapid loss of material from the glass ionomer restoration surface. This patient used an oral moisturizing agent several times daily to reduce the symptoms of dry mouth. The manufacturer of this moisturizing agent reported that the product (when added to water) had a pH of 5.5 to 6.5 (Laclede, Rancho Dominguez, Calif., oral and written communication, August 2001), which is similar to the pH (5.8) of the sodium fluoride used in the study by Wood and colleagues.6
The 86 percent failure rate (six of seven glass ionomer restorations) in patient no. 7 also is similar to the 91 percent failure rate reported in the study by Wood and colleagues.6 Because it is known that an acidic environment adversely affects glass ionomer restorations,22 the frequent use of the slightly acidic oral moisturizing agent may have caused the loss of material from restorations placed in patient no. 7. In addition, other factors such as vigorous tooth brushing or acidic dietary products may have played a role.
|
CONCLUSIONS
|
|---|
The results of our study show that significantly less caries developed at the CSM of the fluoride-releasing glass ionomer restorative materials (Ketac-Fil and Vitremer) compared with amalgam (Tytin) in patients who were less than 50 percent compliant with regard to the daily use of topical neutral sodium fluoride gel. No caries developed within 3 mm of the restorations in patients who were compliant at least 50 percent of the time with regard to the daily use of sodium fluoride gel. The glass ionomer restorations did not undergo a high failure rate as a result of severe surface degradation.
View larger version (137K):
[in this window]
[in a new window]
|
Dr. Haveman is an associate professor, Department of General Dentistry, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229, e-mail "haveman{at}uthscsa.edu". Address reprint requests to Dr. Haveman.
| |
View larger version (138K):
[in this window]
[in a new window]
|
Dr. Summitt is a professor and chairman, Department of Restorative Dentistry, The University of Texas Health Science Center at San Antonio.
| |
View larger version (121K):
[in this window]
[in a new window]
|
Dr. Burgess is a professor and chairman, Department of Operative Dentistry and Bio-materials, Louisiana State University Health Science Center, School of Dentistry, New Orleans.
| |
View larger version (135K):
[in this window]
[in a new window]
|
Ms. Carlson is a dental assistant, Division of Clinical Research, The University of Texas Health Science Center at San Antonio.
| |
|
FOOTNOTES
|
|---|
The authors gratefully acknowledge that this project was funded in part by grant UR6648-21 from the 3M Company, St. Paul, Minn.
|
REFERENCES
|
|---|
- Dodds M, Suddick R. Caries risk assessment for determination of focus and intensity of prevention in a dental school clinic. J Dent Educ 1995;59:945–56.[Medline]
- Question of the month. JADA 2001;132:1514.
- Horiot JC, Schraub S, Bone MC, et al. Dental preservation in patients irradiated for head and neck tumours: a 10-year experience with topical fluoride and a randomized trial between two fluoridation methods. Radiother Oncol 1983;1:77–82.[Medline]
- Jansma J, Vissink A, Gravenmade EJ, Visch LL, Fidler V, Retief DH. In vivo study on the prevention of postradiation caries. Caries Res 1989;23:172–8.[Medline]
- Spak CJ, Johnson G, Ekstrand J. Caries incidence, salivary flow rate and efficacy of fluoride gel treatment in irradiated patients. Caries Res 1994;28:388–93.[Medline]
- Wood RE, Maxymiw WG, McComb D. A clinical comparison of glass ionomer (polyalkenoate) and sliver amalgam restorations in the treatment of class 5 caries in xerostomic head and neck cancer patients. Oper Dent 1993;18:94–102.[Medline]
- Burgess JO. Fluoride-releasing materials: a critical review of in vitro anti-caries effects. Proceedings of Conference on Critical Reviews of Restorative Quandaries; October 1–3, 1998; Banff, Calgary, Canada. Transactions 1998;12:151–76.
- Forsten L. Fluoride release of glass ionomers. J Esthet Dent 1994;6:216–22.[Medline]
- Rothwell M, Anstice HM, Pearson GJ. The uptake and release of fluoride by ion-leaching cements after exposure to toothpaste. J Dent 1998;26:591–7.[Medline]
- Gilmour AS, Edmunds DH, Newcombe RG. Prevalence and depth of artificial caries-like lesions adjacent to cavities prepared in roots and restored with a glass ionomer or a dentin-bonded composite material. J Dent Res 1997;76:1854–61.[Abstract/Free Full Text]
- Nagamine M, Itota T, Torii Y, Irie M, Staninec M, Inoue K. Effect of resin-modified glass ionomer cements on secondary caries. Am J Dent 1997;10:173–8.[Medline]
- Eichmiller FC, Marjenhoff WA. Fluoride-releasing dental restorative materials. Oper Dent 1998;23:218–28.[Medline]
- Baysan A, Lynch E, Ellwood R, Davies R, Petersson L, Borsboom P. Reversal of primary root caries using dentifrices containing 5,000 and 1,100 ppm fluoride. Caries Res 2001;35(1):41–6.[Medline]
- Mjör IA. Glass-ionomer cement restorations and secondary caries: a preliminary report. Quintessence Int 1996;27:171–4.[Medline]
- Mjör IA. The reasons for replacement and the age of failed restorations in general dental practice. Acta Odontol Scand 1997;55:58–63.[Medline]
- McComb D. Caries prevention by fluoride-releasing restorative materials: a review of in-vivo evidence. Proceedings of Conference on Critical Reviews of Restorative Quandaries; October 1–3, 1998; Banff, Calgary, Canada. Transactions 1998;12:179–99.
- Randall R, Wilson N. Glass-ionomer restoratives: a systematic review of a secondary caries treatment effect. J Dent Res 1999;78:628–37.[Abstract/Free Full Text]
- Qvist V, Laurberg L, Poulsen A, Teglers PT. Longevity and cariostatic effects of everyday conventional glass ionomer and amalgam restorations in primary teeth: three year results. J Dent Res 1997;76:1387–96.[Abstract/Free Full Text]
- Donly KJ, Segura A, Wefel JS, Hogan MM. Evaluating the effects of fluoride-releasing dental materials on adjacent interproximal caries. JADA 1999;130:817–25.
- Watson TF. A confocal microscopic study of some factors affecting the adaptation of a light-cured glass ionomer to tooth tissue. J Dent Res 1990;69:1531–8.[Abstract/Free Full Text]
- Sidhu SK, Watson TF. The effect of dehydration on light-cured glass ionomer restorations. Singapore Dent J 1994;19(special issue): 44–8.
- de Gee AJ, van Duinen RN, Werner A, Davidson CL. Early and long-term wear of conventional and resin-modified glass ionomers. J Dent Res 1996;75:1613–9.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
C.M. Carey, M. Spencer, R.J. Gove, and F.C. Eichmiller
Fluoride Release from a Resin-modified Glass-ionomer Cement in a Continuous-flow System: Effect of pH
J. Dent. Res.,
October 1, 2003;
82(10):
829 - 832.
[Abstract]
[Full Text]
[PDF]
|
|
|
TOP
ABSTRACT
BACKGROUND
