Recommendations for conducting controlled clinical studies of dental restorative materials

Oral health-related quality of life and survival analysis after preventive and restorative treatment of molar-incisor hypomineralisation

The aim of this study was to assess the impact of molar-incisor hypomineralisation (MIH) on oral health-related quality of life (OHRQoL) in children and adolescents, including information on restorative care, tooth sensitivity, as well as sociodemographic factors. Thirty-five patients aged between 7 and 17 years underwent a comprehensive oral examination. Severity of MIH was graded using the MIH Treatment Need Index (MIH-TNI), OHRQoL using the Child Oral Health Impact Profile (COHIP-19). Clinical quality of restorations was assessed according to modified FDI-criteria, tooth sensitivity using the Schiff Cold Air Sensitivity Scale (SCASS). The mean age was 11.3 ± 3.0 years, 34% were female. On average, 6.9 ± 2.8 teeth were affected, 62,9% had hypersensitive teeth (SCASS ≥ 1). Eighty-nine percent of patients had received restorative care, with a mean of 3.3 ± 2.1 teeth restored, most often with composite, followed by fissure sealing. Nine percent of restorations failed by the FDI-criteria. Mean estimated survival times for success were 4.9 years (95% CI 3.5; 6.2) and 5.6 years (95% CI 5.0; 6.3) for fissure sealants and composite restorations, respectively. The mean COHIP-19 score was 64.3 ± 8.2 (max. possible score = 76). A higher severity of MIH-TNI correlated significantly with impaired OHRQoL (rs = - 0.38, p = 0.013). However, this was not mirrored in multiple regression analysis. Despite the high rate of restorative treatment with an acceptable failure rate, OHRQoL is reduced in children with MIH. Many teeth affected by MIH remain sensitive. Further studies are needed to assess the benefits of different restorative options.

Clinical performance of non-carious cervical lesions restored with using self-etch mode of adhesives according to the FDI criteria

AIM

The purpose of this study was to evaluate the 18-month retrospective study of self-etch adhesive (Prime&Bond One Select) and self-etch mode of universal adhesives (Single Bond Universal, Gluma Bond Universal) applied to non-carious cervical lesions according to the World Dental Federation criteria.

MATERIALS AND METHODS

Thirty patients without any systemic disease, good oral hygiene, having at least 20 teeth and six non-carious cervical lesions treated using a self-etch mode of adhesives operated between January and March 2017. Accordingly, 335 restorations were evaluated according to the World Dental Federation criteria at 3, 6, 12 and 18 months. Pillai's Trace test was used to determine the interaction of criteria with time and adhesive systems. IBM SPSS Statistics 21.0 program was used in the analysis. Value of P < 0.05 was accepted as a criterion for statistical significance.

RESULTS

At the end of 18 months, participation was 100%. There was a statistically significant difference P < 0.05 between Prime&Bond One Select and Single Bond Universal, Prime&Bond One Select and Gluma Bond Universal in the 18-month period. In terms of marginal staining, fracture of material and retention, recurrence of caries, erosion and abfraction, tooth integrity criteria at the end of the 18 months, Prime&Bond One Select performed clinically very good, Single Bond Universal and Gluma Bond Universal performed clinically good according to World Dental Federation criteria. Marginal adaptation criteria, Prime&Bond One Select, Single Bond Universal and Gluma Bond Universal performed clinically good. Retention loss rate was found to be the lowest in Prime&Bond One Select and the highest in Gluma Bond Universal.

CONCLUSION

Accordingly, 18-month evaluation of all adhesives used in the study showed clinically acceptable results in all of the World Dental Federation criteria.

Retrospective clinical study on the performance and aesthetic outcome of pressed lithium disilicate restorations in posterior teeth up to 8.3 years

OBJECTIVES

Evaluation of cumulative survival and complication rate of monolithic lithium disilicate inlays and partial crowns performed by supervised undergraduate students up to 8.3 years of clinical service.

MATERIALS AND METHODS

In this retrospective clinical study 143 lithium disilicate posterior restorations (IPS e.max Press) were examined according to the FDI criteria. A standardised questionnaire was used to determine patient satisfaction. The aesthetic outcome was evaluated by dentists and dental technicians using intraoral photographs. Data were descriptively analysed. Cumulative survival and success rates were calculated using Kaplan-Meier estimation.

RESULTS

The cumulative survival rate of lithium disilicate restorations was 97.5% after a mean service time of 5.9 years and 95.0% after 8.3 years. The cumulative success rate decreased from 94.4% after 5.9 years to 30.7% after 8.3 years. Repairs were required for 7 restorations (4.9%), and 5 (3.5%) were classified as failures. The results of the questionnaire indicate a high level of patient satisfaction. The subjective aesthetics were assessed more critically by dental technicians compared to dentists.

CONCLUSION

Lithium disilicate posterior restorations survived successfully up to 8.3 years when carried out by undergraduate students.

CLINICAL RELEVANCE

Pressed lithium disilicate glass ceramic inlays and partial crowns are reliable treatment options in posterior teeth.

Revised FDI criteria for evaluating direct and indirect dental restorations-recommendations for its clinical use, interpretation, and reporting

OBJECTIVES

The FDI criteria for the evaluation of direct and indirect dental restorations were first published in 2007 and updated in 2010. Meanwhile, their scientific use increased steadily, but several questions from users justified some clarification and improvement of the living document.

MATERIALS AND METHODS

An expert panel (N = 10) initiated the revision and consensus process that included a kick-off workshop and multiple online meetings by using the Delphi method. During and after each round of discussion, all opinions were collected, and the aggregated summary was presented to the experts aiming to adjust the wording of the criteria as precisely as possible. Finally, the expert panel agreed on the revision.

RESULTS

Some categories were redefined, ambiguities were cleared, and the descriptions of all scores were harmonized to cross-link different clinical situations with possible management strategies: reviewing/monitoring (score 1-4), refurbishment/reseal (score 3), repair (score 4), and replacement (score 5). Functional properties (domain F: fracture of material and retention, marginal adaptation, proximal contact, form and contour, occlusion and wear) were now placed at the beginning followed by biological (domain B: caries at restoration margin, hard tissue defects, postoperative hypersensitivity) and aesthetic characteristics (domain A: surface luster and texture, marginal staining, color match).

CONCLUSION

The most frequently used eleven categories of the FDI criteria set were revised for better understanding and handling.

CLINICAL RELEVANCE

The improved description and structuring of the criteria may help to standardize the evaluation of direct and indirect restorations and may enhance their acceptance by researchers, teachers, and dental practitioners.

Fully Digital versus Conventional Workflows for Fabricating Posterior Three-Unit Implant-Supported Reconstructions: A Prospective Crossover Clinical Trial

This study assessed the clinical variables influencing the success of three-unit implant-supported fixed dental prostheses (ISFDPs) fabricated using either fully digital or conventional workflows. The clinical trial evaluated 10 patients requiring three-unit ISFDPs in the posterior mandible. Maxillomandibular relation records, and digital and conventional impressions were obtained from each patient using an intraoral scanner (IoS) and polyvinylsiloxane (PVS), and the frameworks were fabricated using zirconia and cobalt-chromium, respectively. A 2 µm accuracy scanner scanned the conventional master casts and standard reference models. The stereolithography (STL) files of the digital and conventional impressions were superimposed on the standard model file, and the accuracy was calculated with the best-fit algorithm. The framework adaptation and passivity were assessed using the one-screw and screw resistance tests. The time required for occlusal adjustment of both types of reconstructions, including the duration of the whole treatment, was recorded. The aesthetic appearance of ISFDPs was rated by each patient and clinician using a self-administered visual analogue scale questionnaire and the FDI World Dental Federation aesthetic parameters, respectively. The sample size was based on the power calculation, and alpha was set at 0.05 for the statistical analyses. The impression accuracy, framework adaptation and passivity, and reconstructions aesthetics did not significantly differ between the digital and conventional approaches. The total fabrication time was significantly shorter using the digital workflow. Within the limitations of this clinical study, the fully digital workflow can be used for the fabrication of ISFDPs with a clinical outcome comparable to that of the conventional workflow.

Clinical and Radiographic Success of Resin-bonded Strip Crowns in Primary Incisors with Varying Extents of Sound Tooth Structure Available for Bonding

Context

First-time dental treatment for children is often sought due to carious, malformed, fractured, and discolored teeth. The strip crown represents a highly esthetic and popular option for the restoration of primary anterior teeth. However, there are limited data on the clinical success of these crowns based on the extent of surface area used for adhesion.

Aims settings and design

This in vivo study aimed to assess the clinical, radiographic, and photographic performance of 66 composite strip crown restorations on primary anterior teeth for up to 15 months and compare the outcome based on the extent and surface area of tooth structure available.

Materials and methods

The amount of surface area available in each group after removal of affected enamel was evaluated through 3D scanning of study casts and digital measurements. The teeth were thus grouped into three categories: group I with crown structure involvement up to the incisal one-third, group II with involvement up to the middle of the middle third, and group III with involvement up to the cervical one-third.

Statistical analysis used

Kruskal-Wallis H test and Mann-Whitney U test were used for computation of mean scores for intra- and intergroup comparison, respectively. Scoring was done as per FDI clinical criteria on a scale of 1 to 5.

Results

Group III showed the highest mean scores at different time intervals and also the highest failure rate (52.38%), followed by group II (12%) and group I (5%). The overall retention rate observed for the strip crowns was 77.28% at the end of 15 months.

Conclusion

Strip crowns should be considered for teeth that offer a minimum of half to two-thirds of the healthy tooth structure remaining. Further, longitudinal studies are required to add to the results of the final outcome of these restorations.

Key messages

A critical surface area value of <50 mm² or less than half of the available sound tooth structure was found to be detrimental to the retention rate of these crowns in this study. It could therefore be suggested to consider strip crowns for teeth that offer a minimum of half to two-thirds of healthy tooth structure remaining.

How to cite this article

Grewal N, Jha S, Kaur N. Clinical and Radiographic Success of Resin-bonded Strip Crowns in Primary Incisors with Varying Extents of Sound Tooth Structure Available for Bonding. Int J Clin Pediatr Dent 2021;14(4):454-461.

Replacing single missing teeth in the posterior region using direct composite restorations: Survival and clinical quality

OBJECTIVES

The aim of this pilot study was to test the survival and clinical quality of frugal methods to replace single missing teeth in the posterior region with direct composite restorations of different categories.

METHODS

We performed a detailed intraoral examination and assessed the clinical quality of the restorations according to modified FDI-criteria. Irreparable loss of a restoration was recorded as "failure" (F). Damaged restorations that could be repaired were defined as "survival with repair" (SR). Restorations without any unfavorable events were classified as "success" (S).

RESULTS

The average follow-up time of restorations was 5.07 ± 5.24 years with 15.1% having a follow-up time of more than 10 years. Three unfavorable events were documented. Two restorations (3.8%) were classified as F, one restoration (1.9%) as SR, and the remaining 50 restorations (94.3%) as S. The estimated overall and functional survival rate at 5 years using the Kaplan-Meier method was 96.2% (confidence interval [CI]:85.5% to 99%) and 98% (CI:86.9% to 99.7%), respectively. Ninety-four percent of the restorations were evaluated as good or excellent clinical quality. Most restorations showed no periodontal complications, however, restorations in the mandible showed significantly more plaque accumulation (p=0.002).

CONCLUSIONS

These conservative frugal methods to replace single missing teeth in the posterior region showed promising clinical survival data and quality parameters.

CLINICAL SIGNIFICANCE

Direct composite restorations of different categories can be considered as additional treatment option for gap closure in specific clinical situations.

Effect of thermal cycling on temperature changes and bond strength in different test specimens

Objectives

To investigate temperature changes in various test specimens during thermal cycling and to evaluate difference in micro-tensile repair bond strength in specimens cut from the inner or the outer area of composite blocks after thermal cycling.

Materials and methods

Four rectangular composite blocks of various sizes were fabricated, and thermocouples placed in the centre of the specimens or halfway from the surface to the centre. Composite cylinders were made on ground flat extracted molars, as intended for micro-tensile and shear bond testing, with a thermocouple placed at the centre of the cylinder radius between composite and dentin. The specimens were thermal cycled between 5 °C and 55 °C with 20–60 s dwell times. The highest and lowest temperatures in the test specimens were recorded.

Composite blocks were fabricated and stored in water for a week and then repaired with the same composite. After thermal cycling (5000×, 5 °C and 55 °C with a 20 s dwell time), test specimens were cut for micro-tensile testing.

Results

None of the specimens tested reached the cold and warm water bath temperatures after a 20 s dwell time. In the smallest composite block, the centre core temperature reached 5 °C and 55 °C after 40 s dwell time, but lacked 1 °C after 60 s in the largest block. None of the specimens involving teeth reached water temperatures. The micro-tensile repair strength was significantly different between the outer and the central cut rods (p < .05).

Conclusions

The most commonly used dwell times for thermal cycling are insufficient to create a homogeneous temperature change.

[Quality assessment of aesthetic restorations according to FDI criteria]

The problem of hard dental tissues diseases treatment, the high need of the population to replace poor-quality restorations, as well as the constant dentistry market updating make it necessary to evaluate dental restorations using objective criteria. The purpose of this article is to present the new FDI criteria for evaluating aesthetic restorations and explanations of their use, as well as a quality comparative assessment of restorations made from various light-curing composites. The clinical part of the work was to assess the restoration quality III and IV Black classes. A total of 33 restorations were made. All patients had good oral hygiene (OHIS <0.6±0.02) was characterized by the absence of inflammation or mild inflammation of the gums (GI <0.66±0.04) and high intensity of the carious process (KPU=12.2±0.8). The analysis of the obtained data from the pilot clinical study leads to the following conclusions: new advanced FDI criteria provide complete information about quality of the restorations and can be recommended for evaluating the clinical efficacy of various materials; this evaluation system of restorations is flexible, it can change over time and it allows you to follow the new trends in materials science and restoration methods as accurately as possible.

Criteria for the Replacement of Restorations: Academy of Operative Dentistry European Section

The replacement of a restoration is one of the most common procedures in dentistry. However, the criteria for such intervention, excluding catastrophic failure and persistent discomfort and pain, continue to be the subject of considerable debate. The decision-making process remains subjective on the part of the treating clinician, while the evidence base for refurbishment and repair rather than replacement for the management of defective and failing restorations continues to grow and strengthen. This article, prepared as an Academy of Operative Dentistry European Section consensus publication, reviews existing criteria for the replacement of restorations and encourages practitioners to shift, if not already doing so, to considering the replacement of a restoration as a last resort rather than as a prudent action to be taken if in any doubt about clinical acceptability. Further research in the area, spanning the risk assessment of defective and failing restorations and new diagnostic tools and processes, together with work to enhance the evidence base of restoration repair vs replacement, would be of immense value.

Early complications and performance of 327 heat-pressed lithium disilicate crowns up to five years

PURPOSE

The prospective follow-up aimed to assess the performance of lithium disilicate crowns and clinical reasons of adverse events compromising survival and quality.

MATERIALS AND METHODS

58 patients were treated with 375 heat-pressed monolithic crowns, which were bonded with resin cement. Annual recalls up to five years included a complete dental examination as well as quality assessment using CDA-criteria. Any need for clinical intervention led to higher complication rate and any failure compromised the survival rate. Kaplan-Meier-method was applied to all crowns and a dataset containing one randomly selected crown from each patient.

RESULTS

Due to drop-outs, 45 patients (31 females, 14 males) with the average age of 43 years (range = 17-73) who had 327 crowns (176 anterior, 151 posterior; 203 upper jaw, 124 lower jaw) were observed and evaluated for between 4 and 51 months (median = 28). Observation revealed 4 chippings, 3 losses of retention, 3 fractures, 3 secondary caries, 1 endodontic problem, and 1 tooth fracture. Four crowns had to be removed. Survival and complication rate was estimated 98.2% and 5.4% at 24 months, and 96.8% and 7.1% at 48 months. The complication rate was significantly higher for root canal treated teeth (12%, P<.01) at 24 months. At the last observation, over 90% of all crowns showed excellent ratings (CDA-rating Alfa) for color, marginal fit, and caries.

CONCLUSION

Heat pressed lithium disilicate crowns showed an excellent performance. Besides a careful luting, dentists should be aware of patients' biological prerequisites (grade of caries, oral hygiene) to reach full success with these crowns.

Two-year Randomized Clinical Trial of Self-etching Adhesives and Selective Enamel Etching

OBJECTIVE

The aim of this randomized, controlled prospective clinical trial was to evaluate the clinical effectiveness of restoring noncarious cervical lesions with two self-etching adhesive systems applied with or without selective enamel etching.

METHODS

A one-step self-etching adhesive (Xeno V(+)) and a two-step self-etching system (Clearfil SE Bond) were used. The effectiveness of phosphoric acid selective etching of enamel margins was also evaluated. Fifty-six cavities were restored with each adhesive system and divided into two subgroups (n=28; etch and non-etch). All 112 cavities were restored with the nanohybrid composite Esthet.X HD. The clinical effectiveness of restorations was recorded in terms of retention, marginal integrity, marginal staining, caries recurrence, and postoperative sensitivity after 3, 6, 12, 18, and 24 months (modified United States Public Health Service).

RESULTS

The Friedman test detected significant differences only after 18 months for marginal staining in the groups Clearfil SE non-etch (p=0.009) and Xeno V(+) etch (p=0.004). One restoration was lost during the trial (Xeno V(+) etch; p>0.05).

CONCLUSIONS

Although an increase in marginal staining was recorded for groups Clearfil SE non-etch and Xeno V(+) etch, the clinical effectiveness of restorations was considered acceptable for the single-step and two-step self-etching systems with or without selective enamel etching in this 24-month clinical trial.

FDI World Dental Federation: clinical criteria for the evaluation of direct and indirect restorations-update and clinical examples

In 2007, new clinical criteria were approved by the FDI World Dental Federation and simultaneously published in three dental journals. The criteria were categorized into three groups: esthetic parameters (four criteria), functional parameters (six criteria) and biological parameters (six criteria). Each criterion can be expressed with five scores, three for acceptable and two for non-acceptable (one for reparable and one for replacement). The criteria have been used in several clinical studies since 2007, and the resulting experience in their application has led to a requirement to modify some of the criteria and scores. The two major alterations involve staining and approximal contacts. As staining of the margins and the surface has different causes, both phenomena do not appear simultaneously. Thus, staining has been differentiated into marginal staining and surface staining. The approximal contact now appears under the name "approximal anatomic form" as the approximal contour is a specific, often non-esthetic issue that cannot be integrated into the criterion "esthetic anatomical form". In 2008, a web-based training and calibration tool called e-calib ( www.e-calib.info ) was made available. Clinical investigators and other research workers can train and calibrate themselves interactively by assessing clinical cases of posterior restorations which are presented as high-quality pictures. Currently, about 300 clinical cases are included in the database which is regularly updated. Training for eight of the 16 clinical criteria is available in the program: "Surface lustre"; "Staining (surface, margins)"; "Color match and translucency"; Esthetic anatomical form"; "Fracture of material and retention"; "Marginal adaptation"; "Recurrence of caries, erosion, abfraction"; and "Tooth integrity (enamel cracks, tooth fractures)". Typical clinical cases are presented for each of these eight criteria and their corresponding five scores.

Clinical Evaluation of Resin-based Composites in Posterior Restorations: Two-year Results

Nanohybrid and low-shrinkage posterior resin composites, placed with self-etch adhesive systems in posterior teeth, showed satisfactory and similar results after two years.