Survival analysis of crown margin repair: A retrospective study in a dental school setting

BackgroundRepairing crowns with defective margins is minimally invasive and cost-effective compared with replacement. The authors’ objectives were to examine the survival trajectory of crown margin repairs and to determine the factors associated with survival.MethodsRecords of adult patients from January 2008 through August 2019 were reviewed for crown margin repairs completed at University of Iowa College of Dentistry. A total of 1,002 crown margin repairs were found. Each repair was followed through the end of study in 2019 or until an event (for example, additional repair, endodontic treatment, crown replacement, or extraction). A Cox proportional hazards model was used to study the relationship between selected covariates and time to event.ResultsDuring the follow-up period, 32.8% of the repairs needed reintervention. In the final model, repair material was the only significant covariate. No difference was found between the survival of repairs done with resin-modified glass ionomer and amalgam. However, the repairs done with resin-based composite and conventional glass ionomer were more likely (1.5 times: 95% CI, 1.02 to 2.10 times; and 2 times: 95% CI, 1.40 to 2.73 times, respectively) to need reintervention than were those done with amalgam.ConclusionsMedian survival time of crown margin repairs was 5.1 years (95% CI, 4.48 to 5.72 years). Median survival times for amalgam, resin-modified glass ionomer, resin-based composite, and glass ionomer repair materials were 5.7 years (95% CI, 4.80 to 6.25 years), 5.3 years (95% CI, 4.73 to 6.34 years), 3.2 years (95% CI, 2.51 to 6.19 years), and 3.0 years (95% CI, 2.53 to 3.62 years), respectively.Practical ImplicationsWhen considering crown margin repairs, resin-modified glass ionomer or amalgam is preferable to resin-based composite or glass ionomer.     

Reasons for restorative therapy and the longevity of restorations in adults

The aim of this study was to obtain information on the restorative dental care of adults in Finland. A random sample of private dentists was drawn from the register, and in spring 2000 they were sent a questionnaire requesting them to record information for each restoration placed during one ordinary working day. A total of 800 dentists were contacted and 548 responded. The dentists reported placement of 3,455 restorations. Of these, 5% were Class I, 36% were Class II, 13% were Class III, 9% were Class IV, 21% were Class V, and 16% were extensive restorations including 4 or more surfaces. Overall, composite resin was the most common restorative material, and it was used in 79% of the restorations, whereas amalgam was used in 50%, compomers in 4%, and glass ionomers (either conventional or resin-modified) in 7% of cases. In 5%, of the cases, the tooth was restored with indirect restorative methods, using either gold or ceramic materials. Of the treatments, 65% were replacements of previous restorations. Secondary caries was the most common reason for replacement (36%, 52%, and 41% for composite, glass ionomer, and amalgam, respectively). Other common reasons were fractures of the tooth or restoration (23%, 11%, and 22% for composite, glass ionomer, and amalgam, respectively) and lost composite restorations (16%). The median age of failed restorations was 15 years for amalgam, 6 years for composite, and 7 years for conventional glass ionomer. Although the longevity of tooth coloured restorations was shorter than that of amalgam, comparisons with our previous studies indicate improved survival periods for tooth coloured materials.     

Reasons for restorative therapy and the longevity of restorations in adults

The aim of this study was to obtain information on the restorative dental care of adults in Finland. A random sample of private dentists was drawn from the register, and in spring 2000 they were sent a questionnaire requesting them to record information for each restoration placed during one ordinary working day. A total of 800 dentists were contacted and 548 responded. The dentists reported placement of 3,455 restorations. Of these, 5% were Class I, 36% were Class II, 13% were Class III, 9% were Class IV, 21% were Class V, and 16% were extensive restorations including 4 or more surfaces. Overall, composite resin was the most common restorative material, and it was used in 79% of the restorations, whereas amalgam was used in 5%, compomers in 4%, and glass ionomers (either conventional or resin‐modified) in 7% of cases. In 5% of the cases, the tooth was restored with indirect restorative methods, using either gold or ceramic materials. Of the treatments, 65% were replacements of previous restorations. Secondary caries was the most common reason for replacement (36%, 52%, and 41% for composite, glass ionomer, and amalgam, respectively). Other common reasons were fractures of the tooth or restoration (23%, 11%, and 22% for composite, glass ionomer, and amalgam, respectively) and lost composite restorations (16%). The median age of failed restorations was 15 years for amalgam, 6 years for composite, and 7 years for conventional glass ionomer. Although the longevity of tooth coloured restorations was shorter than that of amalgam, comparisons with our previous studies indicate improved survival periods for tooth coloured materials.     

Restorative service patterns in Australia: amalgam, composite resin and glass ionomer restorations

AIM: To examine the provision of amalgam, composite resin and glass ionomer restorations, and to assess whether these main restorative services varied by patient, visit and oral health characteristics. DESIGN: A cross-sectional survey incorporating a log of service items provided on a typical day. SETTING: Australian private general practice. METHODS: Data on services and patients were collected by a mailed survey from a random sample of dentists from each State/Territory in Australia in 1998-99 with a response rate of 71%. MAIN OUTCOME MEASURES: Rates per visit of amalgam, composite resin and glass ionomer restorations among dentate adults who had received a restoration. RESULTS: Analysis showed older patients had lower amalgam rates but higher glass ionomer rates, composite resin rates were lower at emergency visits, capital city patients had higher amalgam rates but lower composite resin rates, patients with decayed teeth had higher amalgam and composite resin rates, and use of restorative materials varied by clinical problem. CONCLUSIONS: Despite widespread use of alternative materials, amalgam rates remained high in circumstances such as replacement restorations and restorations involving more than one surface. Other restorative materials also had specific applications. Both amalgam and composite resins were provided at higher rates to patients with active caries but composite resins were also used at higher rates for aesthetic problems. Glass ionomer restorations were used at higher rates for initial and one-surface restorations, and for conditions such as root caries and dentinal sensitivity.     

Repair or replacement of defective direct resin-based composite restorations: contemporary teaching in U.S. and Canadian dental schools

BackgroundOpportunities exist to promote minimally invasive dentistry by repairing rather than replacing defective and failing direct resin-based composite restorations. The authors conducted a study to investigate the current teaching of such techniques in U.S. and Canadian dental schools.MethodsIn late 2010, the authors, with the assistance of the Consortium of Operative Dentistry Educators, invited 67 U.S. and Canadian dental schools to participate in an Internet-based survey.ResultsThe response rate was 72 percent. Eighty-eight percent of the dental schools taught repair of defective direct resin-based composite restorations. Of these schools, 79 percent reported providing both didactic and clinical teaching.ConclusionsAlthough teaching repair of defective resin-based composite restorations was included in the didactic curricula of most schools, students in some schools did not gain experience in minimally invasive management of defective resin-based composite restorations by means of performing repair procedures. The American Dental Association's Code on Dental Procedures and Nomenclature does not have a procedure code for resin-based composite restoration repairs, which may limit patients' access to this dental treatment.Clinical ImplicationsTeaching dental students minimally invasive dentistry procedures, including restoration repair, extends the longevity of dental restorations and reduces detrimental effects on teeth induced by invasive procedures, thereby serving the interests of patients.     

Clinical performance and caries inhibition of resin-modified glass ionomer cement and amalgam restorations

BACKGROUND: The authors clinically examined two restorative materials to evaluate their effectiveness in Class II restorations in primary molars and their ability to inhibit recurrent caries. METHODS: Forty subjects, each in need of two Class II restorations in primary molars, took part in this study. Each patient received one Class II restoration of resin-modified glass ionomer cement and one of amalgam. The authors evaluated the restorations at six-month, one-year, two-year and three-year recall appointments. On exfoliation, teeth with experimental restorations were retrieved and microscopically examined for inhibition of demineralization at restoration margins. RESULTS: The results of the clinical evaluation demonstrated no significant differences between the resin-modified glass ionomer cement restorations and the amalgam restorations (P < .05). Polarized light microscopic examination of the returned teeth that were restored as a part of this study indicated that the resin-modified glass ionomer cement had significantly less enamel demineralization at restoration margins than did amalgam (P < .0001). CONCLUSIONS: The resin-modified glass ionomer cement functioned clinically as well as amalgam for Class II restorations in primary molars. However, the resin-modified glass ionomer exhibited significantly less enamel demineralization at restoration margins than did amalgam. CLINICAL IMPLICATIONS: Resin-modified glass ionomer cement restorative material functions well for Class II restorations in primary molars and exhibits less recurrent caries at restoration margins than does amalgam.     

What German dentists choose for their teeth: A Web-based survey of molar restorations and their longevity

Statement of problemWhich restorative material is best suited for treating the posterior molar region is unclear. As dentists presumably choose the most appropriate restoration, German dentists were asked how their own molars were treated.PurposeThe purpose of this survey study was to examine molar restorations and their durability in German dentists.Material and methodsIn the official journal of the Federal Dental Association, German dentists were asked to participate in an online survey that gathered demographic data and information on the type and durability of their molar restorations. To reduce selection bias, the data were weighted for region, sex, and age of the dentist.ResultsThe data set consisted of 1719 molars from 288 dentists. Restorations included gold inlays (25%), composite resin (24.3%), amalgam (11.8%), ceramic inlays (5.4%), glass ionomer cement or compomer (0.8%), gold crowns (21.8%), ceramic crowns (6.6%), and metal-ceramic crowns (4.3%). Notable differences were identified based on the sex, age, and region of the dentist. Women selected increased esthetic options, as did young dentists. Restorations made of gold, amalgam, and base metal had the highest longevity, at more than 20 yearsConclusionsAmong German dentists, restorations with metallic materials dominated in molars, with gold accounting for the largest share. In recent years, the proportion of tooth-colored restorations has increased, and in particular, young dentists use composite resin and ceramics.     

Eight-year study on conventional glass ionomer and amalgam restorations in primary teeth

The aim of this randomized clinical study was to compare the longevity and the cariostatic effects of conventional glass ionomer and amalgam restorations in primary teeth placed in everyday practice in the Danish Public Dental Health Service. All restorations inserted during a 7-month period by 14 clinicians in 2 municipalities were included in the study. The sample consisted of 515 conventional glass ionomer restorations and 543 amalgam restorations in 666 children aged between 2.8 and 13.5 years. The restorations were in contact with 592 unrestored surfaces in primary and permanent teeth. The study was terminated after 8 years, with 2% of the restorations in function and 7% patient dropouts. Fifty percent of the teeth restored with glass ionomer and 63% of those with amalgam were exfoliated with the restoration in situ, while 42% of the glass ionomer and 20% of the amalgam restorations had been repaired or replaced. Fracture of restoration, endodontic complication, and loss of retention were the major reasons for failure. The 50% survival time for glass ionomer restorations in all cavity types was 42 months, while the median survival time for amalgam restorations could not be estimated but exceeded 7.8 years (P < 0.001). Progression of caries lesions on tooth surfaces adjacent to amalgam restorations required operative treatment on 30% of the teeth, while only on 16% of teeth adjacent to glass ionomer restorations. The 75% survival time was 40 months for surfaces in contact with glass ionomer compared to 25 months for surfaces in contact with amalgam (P = 0.005). Multivariate analyses were performed in order to assess the influence of a number of factors on the longevity of restorations, occurrence of prevalent failures, and caries treatment of surfaces in contact with the restorations. Owing to the high frequency of failures of the conventional glass ionomer restorations, it was concluded that they are not an appropriate, universal alternative to amalgam for restorations in primary teeth, although they reduce caries progression and the need for operative treatment of adjacent surfaces.     

Age of restorations at replacement in permanent teeth in general dental practice

The ages of 6,761 restorations replaced in permanent teeth, 6,088 in adults ≥19 years of age and 673 in adolescents ≤18 years, were available for analyses. The results showed that the median age of amalgam restorations in adults was 11 years and that of resin-based composite restorations 8 years. This difference in longevity was significant (P = 0.0001). The median age of failed conventional glass ionomer restorations in adults was 4 years and for resin-modified glass ionomer 2 years. In adolescents, the median longevity of failed amalgam restorations was 5 years and that of composite restorations 3 years, while both types of glass ionomers had a median longevity of 2 years. The data were subdivided based on clinician gender and practice setting. The results showed that the median age of amalgam and composite restorations replaced by male clinicians was higher than that for female clinicians irrespective of clinical setting. The median age of amalgam and composite restorations replaced by salaried dentists was significantly lower than that by private practitioners. Minor differences were noted in longevity of restorations between male and female patients. The age of replaced restorations was shortest for the group of clinicians with the least clinical experience and highest for those that graduated ≥ 30 years ago.

Keywords: Amalgam composite; gender differences; glass; ionomer; practice setting     

Attitudes of Greek dentists towards repair of conservative restorations. An online survey

Objectives: Repair versus replacement of a defective direct restoration is one important step for conserving tooth structure. This study was designed to collect information on the attitudes of Greek dentists towards repairing direct restorations. Methods: An electronic questionnaire with 16 multiple-choice and rank-ordering questions was created online and its URL address was randomly emailed to 800 dentists in the area of Athens, Greece. The questionnaire remained open for 3 months, and after two reminder emails the data collected were analysed statistically to identify differences between clinician''s sex or years of practicing dentistry, using the chi-square and Kruskal–Wallis tests at α = 0.05. Results: Three-hundred and twenty dentists completed and submitted the questionnaire (response rate = 40%). A high proportion (86.8%) of the respondents reported that they routinely repair defective restorations, ranking the order of their frequency as 2.47 for amalgam and 2.41 for resin restorations. The reasons, with the highest ranks, for repairing amalgams were the restoration of bulk fractures (4.10) and restoration of marginal fractures (3.69). For repair of resin restorations, the reasons with the highest ranks were improving their colour (4.04) and removing marginal discoloration (3.99). Moreover, 94.1% of the respondents stated that they were enough, much and very much satisfied with the repair, 1 year after it was performed. Conclusions: A high percentage of Greek dentists are repairing defective direct restorations. There are discrepancies in the indications, techniques and materials used for repairs, such as bulk fractures and marginal restorations. Further studies on the efficacy of repairs, the criteria and procedure protocols are needed. Further, additional clinical education should be offered at the undergraduate or continuing education levels.Key words: Replacement, repair, conservative restorations, questionnaire, online survey     

Treatment options for large posterior restorations: a systematic review and network meta-analysis

BackgroundThe best treatment option for large caries in permanent posterior teeth is still a matter of uncertainty in dental literature. The authors conducted a network meta-analysis to address the challenges related to rehabilitation of these teeth.Types of Studies ReviewedThe authors selected prospective and retrospective studies that compared at least 2 different treatment alternatives for permanent teeth with a minimum of 5 years of follow-up. The authors searched databases from MEDLINE, Scopus, Cochrane Library, and Web of Science in October 2019 without language or year of publication restrictions.ResultsFrom 11,263 studies identified, 43 studies fulfilled the eligibility criteria and were included in the final review. Only 13 studies were randomized controlled trials and were classified as low risk of bias. Gold (annual failure rate of 0.29%) and metal ceramic (annual failure rate of 0.52%) crowns performed better for indirect restorations and direct resin composite performed better for direct restorations (annual failure rate of 2.19%). The most substantial comparisons were between feldspathic and glass ceramics, followed by direct resin composite and amalgam; there were no statistically significant differences between these interventions. Results of the pairwise meta-analysis showed mainly glass ionomer as significantly more prone to failure than amalgam and direct composite resin.Conclusions and Practical ImplicationsReference standard direct and indirect materials except for glass ionomer can be used for restorations of large posterior caries.     

Five-year study of Class II restorations in permanent teeth using amalgam, glass polyalkenoate (ionomer) cermet and resin-based composite materials

The aim of this study was to compare the clinical performance of an amalgam, a glass polyalkenoate (ionomer) cermet material and a resin-based composite material used in small Class II cavities in permanent teeth. All restorations were inserted under rubber dam. They were examined yearly for 3 years. One clinician continued the study up to 5 years. The clinical examination focused on two criteria: clinically acceptable and failure. In addition, impressions were taken of the prepared cavities immediately before restoration and at each clinical examination using an elastomeric material. The study comprised 274 Class II restorations (88 amalgams, 95 cermets and 91 resin composites) placed in 142 adolescent patients. One hundred and sixty-seven restorations were in molar and 107 in premolar teeth. Patient dropout after 5 years resulted in the loss of 161 restorations, evenly distributed for restorative material and type of tooth involved. Four amalgam restorations, 22 glass ionomer cermet and nine resin composite restorations failed. The glass ionomer cermet and amalgam restorations failed primarily due to bulk fractures, while the resin composite restorations failed due to secondary caries and bulk fractures.     

Influence of patient factors on age of restorations at failure and reasons for their placement and replacement

OBJECTIVE: This study examined the reasons given by a selected group of dental practitioners for placement and replacement of restorations and correlated the data provided with patient factors, such as patients' age and gender, caries risk, occlusal function and oral hygiene, with restoration longevity. METHOD: A group of general dental practitioners (GDPs) were recruited to take part in the study. Each participant was asked to record the reason for placement or replacement of restorations from a list of potential reasons. The age and Class of the restoration being replaced was also recorded, as also was the material being used and the material being replaced. RESULTS: Details of reason for placement/replacement was received on 3196 restorations from 32 GDPs. Of the restorations placed, 54% were amalgam, 32% composite, 8% compomer and 7% glass ionomer. The reasons for placement/replacement of the restorations were principally primary caries (28%), secondary caries (29%), margin fracture (10%), tooth fracture (7%), and non-carious defects (6%). Overall, the mean age of restorations at failure was 7.1 years. Of the patients who received glass ionomer restorations, 29% were rated as having poor oral hygiene, compared with 18% of the patients who received amalgam restorations, 18% of the patients who received composite restorations and 23% of the patients who received compomer restorations. Of the patients who received glass ionomer restorations, 35% were rated as having high caries susceptibility, compared with 27% of those receiving amalgam restorations, 21% of those receiving composite restorations and 30% of those receiving compomer restorations. CONCLUSION: Primary caries was the principal reason for initial restorations. Secondary caries was the most prevalent reason for replacement of restorations. The results also indicate a selective application of different materials for different patients.     

From amalgam to composite: selection of restorative materials and restoration longevity in Finland

The aim of this study was to obtain information on restorative dental care in Finland and to analyze the changes in treatment over a 5-year period. A random sample of dentists was drawn from the registers of the health authorities and the dental association in Finland, and in the spring of 1997 a questionnaire was sent requesting the dentists to record information for each restoration placed during a given period. A total of 1,229 dentists were contacted, and 659 responded. The dentists treated 5,305 adults during the study period and placed 6,322 restorations. The most common restorative material was composite resin, which was used in 74.9% of the restorations, whereas amalgam was used in 4.8% and glass ionomers in 9.4% of the restorations. The median ages of failed restorations were nearly 12 years for amalgam, slightly less than 5 years for composite, and slightly more than 4 years for glass ionomer. The results indicate that clinical dentistry in Finland has made a definite step towards the post-amalgam era. However, the functional periods of the failed tooth-colored restorations were disappointingly short and warrant some serious consideration.     

Repair of non-carious amalgam margin defects

This study investigated the microleakage associated with the repair of non-carious amalgam defects using flowable resin composite. Occlusal amalgam preparations were accomplished on 36 non-carious mandibular molars. A standardized 40-micron marginal defect was made by condensing amalgam against a mylar matrix strip. Specimens then underwent a corrosion protocol designed to simulate intraoral corrosion seen with amalgam restorations. The resultant specimens were divided into three treatment groups: 1) No treatment (control); 2) Air abrasion of the amalgam defect surface, acid etching of both amalgam and enamel surfaces, then placement of a flowable composite and 3) Air abrasion of the amalgam defect, application of a fifth-generation dentin bonding agent and placement of the flowable composite. Specimens were thermocycled, sealed with glass ionomer and fingernail polish to within 1 mm of repaired margins, then immersed in basic fuchsin for 24 hours. Specimens were sectioned and microleakage assessed. Results indicated that a flowable resin composite significantly reduced marginal microleakage compared to the control (p < 0.05). There was no difference in microleakage between flowable resin composite repairs done with or without the use of a dentin-bonding agent.     

Zirconia restorations: An American Dental Association Clinical Evaluators Panel survey

BackgroundZirconia is a relatively new dental material used for indirect dental restorations. Little is known about how dental practitioners are using this material in their practice.MethodsA survey on zirconia restorations was developed and administered electronically through e-mail communications to the American Dental Association Clinical Evaluators (ACE) Panel on August 31, 2020. Reminders were sent to nonrespondents, and the survey closed 2 weeks after the launch date.ResultsWhen using zirconia for a restoration, respondents choose it to restore natural teeth (99%) more often than implants (76%). Almost all respondents (98%) use it for posterior crowns, whereas approximately two-thirds (61%) use it for anterior crowns. Restoration removal or replacement and shade matching and translucency were the top 2 cited disadvantages of zirconia, whereas most of the respondents (57%) cited flexural strength or fracture resistance as the biggest advantage. Fine diamonds and ceramic polishers are used most often to polish and adjust zirconia restorations, whereas coarse diamond rotary instruments and those made specifically for zirconia are most frequently used for removing these restorations. Compared with metal ceramic restorations, more than 50% of respondents experience debonding more often with zirconia restorations.ConclusionsDentists recognize the favorable fracture resistance and flexural strength properties of zirconia, and most use similar techniques when adjusting and removing this material. Removing these restorations and shade matching are a struggle for many.Practical ImplicationsDentists may benefit from tips on the best methods to remove, shade match, and adhesively bond zirconia restorations.     

Re-intervention in glass ionomer restorations: What comes next?

AIM: The aim of this study is to report the subsequent treatment provided, over the 11 years' data available, when a re-intervention was considered clinically necessary on a glass ionomer (GI) restoration. METHODS: A detailed sample of treatment records of patients has been established at the Dental Practice Division of the NHS Business Services Authority, consisting of records containing directly placed restorations for adult patients from January 1991. This database contains the records of over half a million restorations. For each direct restoration placed, the subsequent history of that tooth was consulted, for the period up to December 2001, and the restorations divided into three groups: amalgam, composite and GI, the latter being subdivided into anterior teeth, premolars, and molars. RESULTS: Data on 164,036 directly placed restorations were analyzed. Results indicated that, for amalgam and composite restorations, the subsequent treatment was likely to be another restoration in the same material. For GI (24,947 restorations), only one third of restorations, overall, were followed by another GI. In anterior teeth, GI restorations were more often followed by composite than by GI, this trend increasing with increasing time interval since restoration. For premolar teeth, the GI restoration was most likely to be followed by another GI within 4 years, with an increasing trend towards re-intervention by an amalgam or composite in older restorations. For molar teeth, GI restorations were more likely to be followed by an amalgam restoration. CONCLUSION: For GI restorations, on re-intervention, there is variation in the next restoration material used according to tooth position and time interval to re-intervention. GI restorations in anterior and molar teeth are not likely to be followed by another GI restoration.     

Buonocore Memorial Lecture. Review of the clinical survival of direct and indirect restorations in posterior teeth of the permanent dentition

This review provides a survey on the longevity of restorations in stress-bearing posterior cavities and assesses possible reasons for clinical failure. The dental literature, predominantly since 1990, was reviewed for longitudinal, controlled clinical studies and retrospective cross-sectional studies of posterior restorations. Only studies investigating the clinical performance of restorations in permanent teeth were included. Longevity and annual failure rates of amalgam, direct composite restorations, compomers, glass ionomers and derivative products, composite and ceramic inlays and cast gold restorations were determined for Class I and II cavities. Mean (SD) annual failure rates in posterior stress-bearing cavities are: 3.0% (1.9) for amalgam restorations, 2.2% (2.0) for direct composites, 3.6% (4.2) for direct composites with inserts, 1.1% (1.2) for compomer restorations, 7.2% (5.6) for regular glass ionomer restorations, 7.1% (2.8) for tunnel glass ionomers, 6.0% (4.6) for ART glass ionomers, 2.9% (2.6) for composite inlays, 1.9% (1.8) for ceramic restorations, 1.7% (1.6) for CAD/CAM ceramic restorations and 1.4% (1.4) for cast gold inlays and onlays. Publications from 1990 forward showed better results. Indirect restorations exhibited a significantly lower mean annual failure rate than direct techniques (p=0.0031). Longevity of dental restorations is dependent upon many different factors, including material, patient- and dentist-related. Principal reasons for failure were secondary caries, fracture, marginal deficiencies, wear and postoperative sensitivity. We need to learn to distinguish between reasons that cause early failures and those that are responsible for restoration loss after several years of service.     

Implementation of repairs in dental practice: Randomized behavior simulation trial

BackgroundDespite increasing evidence, dentists have not widely adopted repairs. The authors aimed to develop and test potential interventions targeting dentists’ behavior.MethodsProblem-centered interviews were performed. Emerging themes were linked to the Behavior Change Wheel to develop potential interventions. The efficacy of 2 interventions was then tested in a postally delivered behavioral change simulation trial among German dentists (n = 1,472 per intervention). Dentists’ stated repair behavior regarding 2 case vignettes was assessed. Statistical analysis was performed using McNemar test, Fisher exact test, and a generalized estimating equation model (P < .05).ResultsTwo interventions (guideline, treatment fee item) were developed on the basis of identified barriers. A total of 504 dentists participated in the trial (17.1% response rate). Both interventions significantly changed dentists’ behavior toward repairs of composite and amalgam restorations, respectively (guideline: difference [Δ] = +7.8% and Δ = +17.6%, treatment fee item: Δ = +6.4% and Δ = +31.5%; adjusted P < .001). Dentists were more likely to consider repairs if they already performed repairs frequently (odds ratio [OR], 1.23; 95% CI, 1.14 to 1.34) or sometimes (OR, 1.08; 95% CI, 1.01 to 1.16), if they regarded repairs as highly successful (OR, 1.24; 95% CI, 1.04 to 1.48), if their patients preferred repairs over total replacements (OR, 1.12; 95% CI, 1.03 to 1.23), for partially defective composite restorations (OR, 1.46; 95% CI, 1.39 to 1.53), and after receiving 1 of the 2 behavioral interventions (OR, 1.15; 95% CI, 1.13 to 1.19).ConclusionsSystematically developed interventions targeting dentists’ repair behaviors are likely efficacious to promote repairs.Practical ImplicationsMost partially defective restorations are replaced completely. Effective implementation strategies are required to change dentists’ behavior.This trial was registered at https://www.clinicaltrials.gov. The registration number is NCT03279874 for the qualitative phase and NCT05335616 for the quantitative phase.