Abstract
Background/purpose
As esthetic demands with direct restorations, tooth-colored materials were used to replace amalgam filling gradually. However, little is known about the tooth-colored restorative materials for decayed teeth in Taiwan. In this study, the use of composite resin, glass ionomer cement, and compomer was analyzed by National Health Insurance Research Database (NHIRD).
Materials and methods
A retrospective study was conducted to analyze the registered database compiled by Taiwanese NHIRD from 1997 to 2013. The results were further to analyze the application of tooth-colored restorative materials by sex and age. In addition, time trends of dental visits for each tooth-colored restorative material were also investigated.
Results
The average annual composite resin filling (CRF) ratio was 18.41% of nationwide population in Taiwan. The prevalence of CRF stratified by sex and age was significantly increased from 1997 to 2013 (P for trend <0.0001). The time trends of dental visits for CRF were significantly increased (P for trend <0.0001). The average annual glass ionomer cement filling (GICF) ratio was 1.79% of Taiwanese population. The prevalence of GICF stratified by sex and age was demonstrated a decreased pattern (P for trend <0.0001). The time trends of dental visits for GICF were significantly decreased (P for trend <0.0001). The average annual compomer filling ratio was 0.57% of whole population in Taiwan.
Conclusion
Form the results of this registry-based study, a significant increased trend of CRF for decayed teeth was observed in Taiwanese population during past 17 years.
Keywords: Tooth-colored restorative materials, Composite resin, Glass ionomer cement, Compomer, Taiwan, National health insurance research database
Introduction
Many dental restorative materials have been used for decayed teeth. Although, amalgam is the most cost effective restorative material. However, mercury contained in amalgam has been raised public health concerns about environmental pollution and the association with neurodegenerative disorders.1, 2, 3 As esthetic demands with direct restorations, tooth-colored restorative materials including glass ionomer cement, composite resin, and compomer have been used to replace amalgam filling.4,5 These materials have many advantages such as same color as the original teeth, fluoride-releasing, and improved adhesion to enamel and dentin.4, 5, 6
Glass ionomer cement and compomer exhibit as ideal fluoride-chargers on the fluoride concentration of surrounding oral environments.6 They are the ideal restorative materials for the restorations of patients with rampant caries, primary decay, and root caries.6,7 Composite resin displays more esthetic appearance with natural tooth looking. Through the modifications in formulation over past decade, composite resin showed the most valuable wear resistance and mechanical performance among tooth-colored materials.5,8 In spite of high cost of dental adhesive, composite resin is still welcomed to be the most popular one for direct restorations in the world.5
In Taiwan, restorative materials for decayed teeth including amalgam, glass ionomer cement, compomer, and composite resin are covered by National Health Insurance (NHI) system. Recently, a nationwide population-based study demonstrated the decreased trends of amalgam restoration for decayed teeth in Taiwan.9 However, little is known about the prevalence of tooth-colored materials for decayed teeth in Taiwan. Therefore, the National Health Insurance Research Database (NHIRD) was conducted to investigate the tooth-colored materials for decayed teeth from 1997 to 2013.
Materials and methods
Data source
Longitudinal Health Insurance Database 2010 (LHID2010) was used to evaluate the prevalence of tooth-colored restorative materials for decayed teeth in Taiwan. Briefly, all the original claims data and registration files from 2000 to 2013 for 1 million individuals randomly sampled from the Registry for Beneficiaries of the National Health Institute program in 2010 were assembled as LHID2010 and released to public for academic researches.2,3,10,11 This study was approved by the Chung Shan Medical University Hospital Ethics Review Board (CSMUH No. CS2-17086).
Identification of tooth-colored restorative materials
Subjects of this study were captured from the LHID 2010 who received dental treatments between 1997 and 2013. To validate the tooth-colored restorative materials for decayed teeth, the treatment codes of the NHI system were used to identify composite resin filling (CRF), glass ionomer cement filling (GICF), and compomer for root caries filling. The treatment codes for CRF are 89004, 89005, 89008, 89009, 89010, 89012, 89014, 89015, 89104, 89105, 89108, 89109, 89110, 89112, 89114, and 89115. The treatment codes 89011 and 89111 indicate GICF. The treatment codes for compomer are 89013 and 89113.
In this study, age stratification was divided by three-stage age group (people aged 0–14 years, 15–64 years, and ≥65 years) as described previously.12 In addition, time trends of dental visits for each tooth-colored restorative material were also investigated.
Statistical analysis
The annual prevalence rate of tooth-colored restorative materials by sex and age was examined by P for trend test. In addition, time trends of dental visits for tooth-colored restorative materials by sex were also analyzed by P for trend test. All statistical analyses were performed by using SAS software version 9.4 (SAS Institute Inc, Cary, NC, USA).
Results
The sex-specific annual ratio of CRF from 1997 to 2013 is shown in Table 1. The average annual CRF ratio was 18.41%. The ratio of CRF was increased significantly from 8.2% in 1997 to 23.7% in 2013. In addition, female patients had higher ratio of CRF than those of male patients. As shown in Fig. 1, the annual ratio of CRF was significantly increased both in male and female groups (P for trend <0.0001).
Table 1.
Prevalence of composite resin filling (CRF) by sex.
| Populationa | Female | Male | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Year | N | N of CRF | P | N | N of CRF | P | N | N of CRF | P |
| 1997 | 873,314 | 71,793 | 8.2 | 447,155 | 43,575 | 9.7 | 426159 | 28,218 | 6.6 |
| 1998 | 884,703 | 108,012 | 12.2 | 452,635 | 64,300 | 14.2 | 432068 | 43,712 | 10.1 |
| 1999 | 896,766 | 124,645 | 13.9 | 458,408 | 73,680 | 16.1 | 438358 | 50,965 | 11.6 |
| 2000 | 909,679 | 133,177 | 14.6 | 464,573 | 77,817 | 16.8 | 445106 | 55,360 | 12.4 |
| 2001 | 920,773 | 148,160 | 16.1 | 469,857 | 85,560 | 18.2 | 450916 | 62,600 | 13.9 |
| 2002 | 931,059 | 156,792 | 16.8 | 474,814 | 90,250 | 19.0 | 456245 | 66,542 | 14.6 |
| 2003 | 940,741 | 163,417 | 17.4 | 479,392 | 93,174 | 19.4 | 461349 | 70,243 | 15.2 |
| 2004 | 950,273 | 178,244 | 18.8 | 483,900 | 101,215 | 20.9 | 466373 | 77,029 | 16.5 |
| 2005 | 959,162 | 185,378 | 19.3 | 488,067 | 104,659 | 21.4 | 471095 | 80,719 | 17.1 |
| 2006 | 968,175 | 192,249 | 19.9 | 492,371 | 108,194 | 22.0 | 475804 | 84,055 | 17.7 |
| 2007 | 976,845 | 199,401 | 20.4 | 496,545 | 111,931 | 22.5 | 480300 | 87,470 | 18.2 |
| 2008 | 985,298 | 210,691 | 21.4 | 500,613 | 118,140 | 23.6 | 484685 | 92,551 | 19.1 |
| 2009 | 993,545 | 219,691 | 22.1 | 504,507 | 122,494 | 24.3 | 489038 | 97,197 | 19.9 |
| 2010 | 999,992 | 222,015 | 22.2 | 507,574 | 124,294 | 24.5 | 492418 | 97,721 | 19.8 |
| 2011 | 989,028 | 223,101 | 22.6 | 502,596 | 123,840 | 24.6 | 486432 | 99,261 | 20.4 |
| 2012 | 977,414 | 227,498 | 23.3 | 497,382 | 126,682 | 25.5 | 480032 | 100,816 | 21.0 |
| 2013 | 964,581 | 228,559 | 23.7 | 491,386 | 127,258 | 25.9 | 473195 | 101,301 | 21.4 |
N: number.
P: prevalence rate (%).
The population obtained from Longitudinal Health Insurance Database 2010.
Figure 1.
Time trends of composite resin filling (CRF) in Taiwan. CRF demonstrated an increased tendency from 1997 to 2013 (P for trend <0.0001).
The ratio of CRF stratified by age is shown in Fig. 2. Among the whole population, 0–14 years age group had the largest number of CRF. People who aged ≥65 years had the lowest CRF. The increased trends of CRF were found in three age groups (P for trend <0.0001).
Figure 2.
Composite resin filling stratified by three-stage age group demonstrated an increased pattern (P for trend <0.0001).
Time trends of dental visits for CRF are demonstrated in Table 2. The trends of dental visits for CRF were between 16.2% in 1997 and up to 31.6% in 2013. Female patients had higher dental visits for CRF than male patients. As illustrated in Fig. 3, the annual ratio of dental visits for CRF was significantly increased both in male and female groups (P for trend <0.0001).
Table 2.
Dental visits for composite resin filling (CRF) by sex.
| Populationa | Female | Male | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Year | Dental visits | Dental visits for CRF | P | Dental visits | Dental visits for CRF | P | Dental visits | Dental visits for CRF | P | sex ratio |
| 1997 | 821,749 | 133,410 | 16.2 | 464,015 | 82,042 | 17.7 | 357734 | 51,368 | 14.4 | 1.6 |
| 1998 | 879,538 | 209,784 | 23.9 | 494,569 | 126,301 | 25.5 | 384969 | 83,483 | 21.7 | 1.5 |
| 1999 | 910,151 | 244,086 | 26.8 | 509,311 | 146,076 | 28.7 | 400840 | 98,010 | 24.5 | 1.5 |
| 2000 | 927,256 | 258,144 | 27.8 | 515,194 | 152,192 | 29.5 | 412062 | 105,952 | 25.7 | 1.4 |
| 2001 | 973,731 | 284,930 | 29.3 | 534,203 | 166,416 | 31.2 | 439528 | 118,514 | 27.0 | 1.4 |
| 2002 | 994,296 | 299,872 | 30.2 | 546,412 | 174,491 | 31.9 | 447884 | 125,381 | 28.0 | 1.4 |
| 2003 | 1,008,524 | 313,374 | 31.1 | 550,542 | 180,021 | 32.7 | 457982 | 133,353 | 29.1 | 1.3 |
| 2004 | 1,119,221 | 343,741 | 30.7 | 608,742 | 196,359 | 32.3 | 510479 | 147,382 | 28.9 | 1.3 |
| 2005 | 1,126,712 | 354,420 | 31.5 | 610,533 | 200,667 | 32.9 | 516179 | 153,753 | 29.8 | 1.3 |
| 2006 | 1,140,491 | 365,534 | 32.1 | 618,701 | 206,660 | 33.4 | 521790 | 158,874 | 30.4 | 1.3 |
| 2007 | 1,178,880 | 376,079 | 31.9 | 639,655 | 211,784 | 33.1 | 539225 | 164,295 | 30.5 | 1.3 |
| 2008 | 1,221,994 | 399,423 | 32.7 | 663,310 | 224,315 | 33.8 | 558684 | 175,108 | 31.3 | 1.3 |
| 2009 | 1,264,598 | 413,706 | 32.7 | 682,827 | 231,488 | 33.9 | 581771 | 182,218 | 31.3 | 1.3 |
| 2010 | 1,271,549 | 412,831 | 32.5 | 690,449 | 231,519 | 33.5 | 581100 | 181,312 | 31.2 | 1.3 |
| 2011 | 1,265,743 | 411,564 | 32.5 | 683,504 | 228,840 | 33.5 | 582239 | 182,724 | 31.4 | 1.3 |
| 2012 | 1,292,331 | 416,323 | 32.2 | 700,483 | 232,333 | 33.2 | 591848 | 183,990 | 31.1 | 1.3 |
| 2013 | 1,313,734 | 414,901 | 31.6 | 712,926 | 231,447 | 32.5 | 600808 | 183,454 | 30.5 | 1.3 |
P: percentage.
The population obtained from Longitudinal Health Insurance Database 2010.
Figure 3.
Time trends of dental visits for composite resin filling (CRF). CRF demonstrated an increased pattern from 1997 to 2013 (P for trend <0.0001).
The sex-specific annual ratio of GICF from 1997 to 2013 is shown in Table 3. The average annual GICF ratio was 1.79%. The ratio of GICF was decreased significantly from 3.3% in 1998 to 0.9% in 2013. As shown in Fig. 4, the annual ratio of GICF was significantly decreased both in male and female groups (P for trend <0.0001).
Table 3.
Prevalence of glass Ionomer cement filling (GICF) by sex.
| Populationa | Female | Male | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Year | N | N of GICF | P | N | N of GICF | P | N | N of GICF | P |
| 1997 | 873,314 | 23,708 | 2.7 | 447,155 | 12,309 | 2.8 | 426159 | 11,399 | 2.7 |
| 1998 | 884,703 | 29,137 | 3.3 | 452,635 | 15,135 | 3.3 | 432068 | 14,002 | 3.2 |
| 1999 | 896,766 | 28,130 | 3.1 | 458,408 | 14,656 | 3.2 | 438358 | 13,474 | 3.1 |
| 2000 | 909,679 | 24,765 | 2.7 | 464,573 | 12,760 | 2.7 | 445106 | 12,005 | 2.7 |
| 2001 | 920,773 | 23,329 | 2.5 | 469,857 | 11,784 | 2.5 | 450916 | 11,545 | 2.6 |
| 2002 | 931,059 | 19,930 | 2.1 | 474,814 | 10,197 | 2.1 | 456245 | 9733 | 2.1 |
| 2003 | 940,741 | 17,400 | 1.8 | 479,392 | 8974 | 1.9 | 461349 | 8426 | 1.8 |
| 2004 | 950,273 | 16,398 | 1.7 | 483,900 | 8354 | 1.7 | 466373 | 8044 | 1.7 |
| 2005 | 959,162 | 15,188 | 1.6 | 488,067 | 7701 | 1.6 | 471095 | 7487 | 1.6 |
| 2006 | 968,175 | 13,614 | 1.4 | 492,371 | 6932 | 1.4 | 475804 | 6682 | 1.4 |
| 2007 | 976,845 | 12,452 | 1.3 | 496,545 | 6228 | 1.3 | 480300 | 6224 | 1.3 |
| 2008 | 985,298 | 12,106 | 1.2 | 500,613 | 6152 | 1.2 | 484685 | 5954 | 1.2 |
| 2009 | 993,545 | 11,571 | 1.2 | 504,507 | 5808 | 1.2 | 489038 | 5763 | 1.2 |
| 2010 | 999,992 | 10,490 | 1.0 | 507,574 | 5368 | 1.1 | 492418 | 5122 | 1.0 |
| 2011 | 989,028 | 9786 | 1.0 | 502,596 | 4961 | 1.0 | 486432 | 4825 | 1.0 |
| 2012 | 977,414 | 9214 | 0.9 | 497,382 | 4641 | 0.9 | 480032 | 4573 | 1.0 |
| 2013 | 964,581 | 8571 | 0.9 | 491,386 | 4365 | 0.9 | 473195 | 4206 | 0.9 |
N: number.
P: prevalence rate (%).
The population obtained from Longitudinal Health Insurance Database 2010.
Figure 4.
Time trends of glass ionomer cement filling (GICF) in Taiwan. GICG demonstrated a decreased tendency from 1997 to 2013 (P for trend <0.0001).
The ratio of GICF stratified by age is shown in Fig. 5. Among the whole population, 0–14 years age group had the largest number of GICF. People who aged between 15 and 64 years had the lowest GICF. The decreased trends of GICF were found in three age groups (P for trend <0.0001).
Figure 5.
Glass ionomer cement filling stratified by three-stage age group demonstrated a phase down pattern (P for trend <0.0001).
Time trends of dental visits for GICF are demonstrated in Table 4. The trends of dental visits for GICF were between 5.2% in 1998 and down to 0.9% in 2013. There were no significantly different dental visits for GICF between male and female. As illustrated in Fig. 6, the annual ratio of dental visits for GICF was significantly decreased both in male and female groups (P for trend <0.0001).
Table 4.
Dental visits for glass ionomer cement filling (GICF) by sex.
| Populationa | Female | Male | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Year | Dental visits | Dental visits for GICF | P | Dental visits | Dental visits for GICF | P | Dental visits | Dental visits for GICF | P | sex ratio |
| 1997 | 821,749 | 37,172 | 4.5 | 464,015 | 18,675 | 4.0 | 357734 | 18,497 | 5.2 | 1.0 |
| 1998 | 879,538 | 45,846 | 5.2 | 494,569 | 23,261 | 4.7 | 384969 | 22,585 | 5.9 | 1.0 |
| 1999 | 910,151 | 43,391 | 4.8 | 509,311 | 22,105 | 4.3 | 400840 | 21,286 | 5.3 | 1.0 |
| 2000 | 927,256 | 37,233 | 4.0 | 515,194 | 18,760 | 3.6 | 412062 | 18,473 | 4.5 | 1.0 |
| 2001 | 973,731 | 34,606 | 3.6 | 534,203 | 17,163 | 3.2 | 439528 | 17,443 | 4.0 | 1.0 |
| 2002 | 994,296 | 28,808 | 2.9 | 546,412 | 14,523 | 2.7 | 447884 | 14,285 | 3.2 | 1.0 |
| 2003 | 1,008,524 | 24,528 | 2.4 | 550,542 | 12,403 | 2.3 | 457982 | 12,125 | 2.6 | 1.0 |
| 2004 | 1,119,221 | 23,078 | 2.1 | 608,742 | 11,542 | 1.9 | 510479 | 11,536 | 2.3 | 1.0 |
| 2005 | 1,126,712 | 20,925 | 1.9 | 610,533 | 10,425 | 1.7 | 516179 | 10,500 | 2.0 | 1.0 |
| 2006 | 1,140,491 | 18,735 | 1.6 | 618,701 | 9380 | 1.5 | 521790 | 9355 | 1.8 | 1.0 |
| 2007 | 1,178,880 | 16,647 | 1.4 | 639,655 | 8177 | 1.3 | 539225 | 8470 | 1.6 | 1.0 |
| 2008 | 1,221,994 | 16,438 | 1.3 | 663,310 | 8127 | 1.2 | 558684 | 8311 | 1.5 | 1.0 |
| 2009 | 1,264,598 | 15,454 | 1.2 | 682,827 | 7618 | 1.1 | 581771 | 7836 | 1.3 | 1.0 |
| 2010 | 1,271,549 | 14,035 | 1.1 | 690,449 | 7028 | 1.0 | 581100 | 7007 | 1.2 | 1.0 |
| 2011 | 1,265,743 | 12,920 | 1.0 | 683,504 | 6448 | 0.9 | 582239 | 6472 | 1.1 | 1.0 |
| 2012 | 1,292,331 | 12,085 | 0.9 | 700,483 | 5970 | 0.9 | 591848 | 6115 | 1.0 | 1.0 |
| 2013 | 1,313,734 | 11,202 | 0.9 | 712,926 | 5599 | 0.8 | 600808 | 5603 | 0.9 | 1.0 |
P: percentage.
The population obtained from Longitudinal Health Insurance Database 2010.
Figure 6.
Time trends of dental visits for glass ionomer cement filling (GICF). GICF demonstrated a reduced pattern from 1997 to 2013 (P for trend <0.0001).
In Taiwan, the payment from NHI for the restoration of compomer for root caries filling since 2012. The indication of compomer filling is guided for the age ≥50 years old people with root caries. The annual ratio of compomer for root caries filling was 0.581% in 2012 and 0.559% in 2013, respectively. The dental visits for compomer for root caries filling were 7391 individuals in 2012 and 7268 individuals in 2013, respectively.
Discussion
Dental caries is prevalent worldwide and remains a major public health problem.13 In Taiwan, dental caries was also reported as the main disease of oral cavity by NHI system in 2020.14 Tooth-colored restorative materials such as glass ionomer cement, compomer, and fluoridated composite resin were developed not only for the prevention of marginal gaps, but also release of fluoride as well antimicrobial activity.5, 6, 7 These materials are increasingly demanded by patients and applied by dentists.
Glass ionomer cement were different from resin-based materials that they were water-based and set through an acid/base reaction.15 In addition, they were self-adhesive to tooth structure through an ion-exchange mechanism and released fluoride ions. This material has been widely advocated for minimally invasive dentistry for caries prevention. However, there are several disadvantages including sensitivity to saliva/water during the early stages, lack of sufficient flexural strength and fracture toughness, and the change of translucency and esthetic.6 Composite resin is assembled with initiator, monomer, and the filler that could provide esthetics and a modicum of strength with correct placement.16
To the best of our knowledge, this is the first longitudinal survey of tooth-colored restorative materials in Taiwan. In this study, the average annual CRF and GICF ratio was 18.41% and 1.79% of nationwide population in Taiwan, respectively. The prevalence of CRF was significantly increased and GICF was demonstrated a decreased pattern. In addition, the increased time trends of dental visits for CRF and the fall of dental visits for GICF were also demonstrated in Taiwan.
In the present study, 0–14 years old group equivalent to pediatric patients had the greater demands for seeking CRF and GICF for decayed teeth. Previously, a nationwide population-based survey has reported that the dental caries rate for preschool children in Taiwan was found in an increased tendency from 2000 to 2012.17 Our results were in agreement with a recent report that the pediatric patients had the largest dental visit for dental caries and medical expenses from the website of the Taiwan NHI Administration.18 The phenomenon of such a high dental use rate for dental caries may be due to the preventive dental health service for children program by NHI since July, 2004. After comprehensive oral examination for pediatric population in school, detected dental problems will be advised for further dental managements. However, the actual reasons still remain to be further elucidated.
In this study, the number of decayed teeth, people, and dental visits treated by CRF have increased year by year. Similar results revealed that the time trends of CRF in posterior restoration were found to increase from 87.1% in 2010 to 99.5% in 2019 in one university dental clinic.19 A previous survey reported that current dental practice trends and patients' esthetic demands might be played as the important factors to choose tooth-colored restorative materials but not dental amalgam.20 The policy to phase down and phase out amalgam towards mercury-free restorations may be crucial to affect dentists’ perceptions and attitudes to reduce non-amalgam restoration for decayed teeth. However, the actual justification is still needed to be further investigated.
The reasons why the prevalence of CRF were higher than GICF. The main explanation may be due to the esthetic outcome that CRF could simulate the same color as the original teeth than GICF. In addition, the medical expenses of NHI for CRF is significant higher than GICF. The financial inducements might influence the dentists' preference for CRF than GICF. However, further assessments of patients' perceptions or dentists’ attitudes towards CRF are warranted.
The word “compomer” comes from composite and glass ionomer. Compomer is composed of polyacid-modified composite resin and glass ionomer component.15 Compomer has the same advantages as composite resin and with the additional advantages of fluoride release and ease of handling. Compomer paid for root caries filling by NHI was started from 2012 in Taiwan. However, only 2 year's data could be obtained from LHID2010. Thus, further study for long term monitoring compomer for root caries filling is required.
The strength of this study is the use of nationwide population-based data which contains complete medical information of all insured individuals. The justified and validated medical charts were ensured by diagnosis and treatment coding system in NHIRD. Sufficient sample size, generalizability, and statistical power are available in this database to assess the use of tooth-colored restorative materials in Taiwan. The results could truly reflect the real situation of tooth-colored restorations in Taiwan. In addition, our results can partly explain the phenomenon of a phase down pattern of amalgam filling in Taiwan.9
Some potential limitations of this study should be noted. First, the restorations of tooth-colored restorative materials for decayed teeth were based on the registry from NHIRD. Self-payment of tooth-colored restorative materials for decayed teeth by patients were not included in this survey. Second, NHI treatment codes were use to identify the restorations of tooth-colored restorative materials for decayed teeth. The decayed deciduous teeth or permeant teeth could not be differentiated. In addition, the repeated restoration of same tooth cannot be ruled out. Third, the demands of tooth-colored restorative materials from patients or dentists could not obtained from NHIRD. Finally, the exact locations of tooth-colored restorative materials placement could not be obtained from NHIRD. It is hard to justify the different pattern among CRF, GICF, and compomer for the restoration of decayed teeth.
With the limitations of this study, it is clearly demonstrated that the trend of CRF was significantly increased from 1997 to 2013. The further investigations of the possible reasons such as phase-down of amalgam, current teeth restorative trend, or patients’ esthetic demand are necessary to be clarified.
Declaration of competing interest
The authors have no conflicts of interest relevant to this article.
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