Carious Tissue Research Articles

Microhardness of sub-restoration dentine in primary molars after carious tissue removal to soft and firm dentine

To compare the microhardness of sub-restoration dentine after selective carious tissue removal and placing glass ionomer restorative cement. Forty-three primary molars with carious lesions extended to the inner third of dentine in subjects aged 8–12 years were included. The teeth were randomly assigned to the following carious tissue removal conditions: Group 1 - removal to the soft dentine, Group 2 - removal to the firm dentine, and Group 3 - removal to the hard dentine. Following restoration with glass ionomer restorative cement for three to six months, 30 tooth samples underwent microhardness testing performed on sub-restoration dentine and sound dentine. The Wilcoxon signed-rank test was used to compare the microhardness values of sound dentine and sub-restoration dentine within the group. The Kruskal–Wallis test was used to analyse the microhardness of the sub-restoration dentine across the three groups. All 30 teeth available for analysis were asymptomatic, with no signs of pulpitis. The average microhardness values of sub-restoration dentine and sound dentine ranged from 16 to 23 KHN and 20 to 27 KHN, respectively. In each group, the microhardness value of the sub-restoration dentine was significantly lower than that of the sound dentine ( p < 0.01). There were no significant differences in the microhardness values of sub-restoration dentine relative to that sound dentine among three groups ( p = 0.86). The microhardness values of sub-restoration dentine with selective carious tissue removal were comparable to those with complete carious tissue removal after glass ionomer restorative cement placement.

Substantial regional differences in the biomechanical behavior of molar treated with selective caries tissue removal technique: a finite element study

ObjectivesSelective caries removal (SCR) is recommended over non-selective removal for managing deep carious lesions to avoid pulp exposure and maintain pulp vitality. During SCR, residual carious dentin is left behind and sealed beneath the restoration. The biomechanical effects of such residual lesions on the restored tooth remain unclear and were assessed using finite element modeling (FEM). MethodsBased on μ-CT images of a healthy permanent human third molar, we developed five finite element models. Generic class I and II cavity restorations were modeled where residual lesions of variable sizes were either left or fully removed on occlusal and proximal surfaces. The cavities were restored with adhesive composite. All 3D-FE models were compared with a model of a healthy, non-treated molar. A vertical load of 100 N was applied onto the occlusal surface. ResultsRegardless of the lesion size, in molars with occlusal lesions higher mean stresses were predicted along the filling-lesion interface than in all other models. The smallest occlusal lesion (Ø1 = 1 mm) resulted in the highest maximum stresses at the filling-lesion interface with large stress concentrations at the filling walls indicating failure risk. In conclusion, lesion site and extent are influencing parameters affecting the filling-lesion interactions and thus the biomechanical behavior of the tooth after SCR. SignificanceRetaining carious lesions around the pulpal floor affects the deformation and stress states in tooth-filling complexes. The higher stresses observed in molars with occlusal lesions may affect restoration stability and longevity. Suprisingly, more extended occlusal lesions may provide a more favorable tooth performance than less extended ones. In contrast, in molars with proximal lesions the residual lesion had only limited effect on the tooth’s biomechanical condition.

Strategies of Carious Tissue Removal in Deep Carious Lesions among Dentists in Iraq: Online Based Survey Study

The aim was to find out the preferences of dentists in Iraq regarding strategies of carious tissue removalin management of deep carious lesions (CR) in asymptomatic teeth and how demographics (sex, years ofexperience, qualification, specialty, place of work) influences these preferences. An online questionnaireof two months duration was constructed and distributed randomly via social media (Facebook). Thequestionnaire’ questions investigated the demographics, CR (included non-selective removal to hard dentine(NS), stepwise (SW) and selective (SE) removal). 238 dentists participated in the study, 164 (69%), 56(23.5%) and 18 (7.5%) of respondents prefer NS, SW and SEremoval, respectively. Significantly both GDPand males prefer NS more than Endodontists and females (P&lt;0.05), Percent of respondents work in privateclinics who perform non-selective removal (53.6%) significantly lower than those who work in hospitals(73.6%) (p&lt;0.01). less invasive CR significantly associated with being an endodontist or female or work ina private clinic (OR=2.02, CI 95% 1.02-4.0), (OR=2.04, CI 95% 1.12-3.7) and (OR=2.1, CI 95% 1.0-4.0),respectively. In conclusion Iraqi GDPs prefer invasive strategy of carious tissue removal in management ofdeep carious lesions. Specialty, place of work and sex of respondents affected these choices significantly

Photoacoustic imaging of occlusal incipient caries in the visible and near-infrared range.

PurposeThis study aimed to demonstrate the presence of dental caries through a photoacoustic imaging system with visible and near-infrared wavelengths, highlighting the differences between the 2 spectral regions. The depth at which carious tissue could be detected was also verified.Materials and MethodsFifteen permanent molars were selected and classified as being sound or having incipient or advanced caries by visual inspection, radiography, and optical coherence tomography analysis prior to photoacoustic scanning. A photoacoustic imaging system operating with a nanosecond pulsed laser as the light excitation source at either 532 nm or 1064 nm and an acoustic transducer at 5 MHz was developed, characterized, and used. En-face and lateral (depth) photoacoustic signals were detected.ResultsThe results confirmed the potential of the photoacoustic method to detect caries. At both wavelengths, photoacoustic imaging effectively detected incipient and advanced caries. The reconstructed photoacoustic images confirmed that a higher intensity of the photoacoustic signal could be observed in regions with lesions, while sound surfaces showed much less photoacoustic signal. Photoacoustic signals at depths up to 4 mm at both 532 nm and 1064 nm were measured.ConclusionThe results presented here are promising and corroborate that photoacoustic imaging can be applied as a diagnostic tool in caries research. New studies should focus on developing a clinical model of photoacoustic imaging applications in dentistry, including soft tissues. The use of inexpensive light-emitting diodes together with a miniaturized detector will make photoacoustic imaging systems more flexible, user-friendly, and technologically viable.

Selective carious tissue removal and glass ionomer liner reduction of pulp stress in bulk fill resin composite restorations.

To evaluate the effect of selective or nonselective carious tissue removal and the use of a resin-modified glass ionomer (RMGIC) liner under bulk fill resin composite restoration on the stress at the pulp chamber, the elastic moduli of hard, firm, soft and intact dentin were calculated using nanoindentation. Post-gel shrinkage of the bulk fill resin composite and RMGIC were determined using the strain-gauge method. Six finite element models were created by using digital radiography with the combination of two study factors: a) carious tissue removal: selective removal or nonselective removal of carious tissue, and b) use of RMGIC liner: with or without 1.0 mm of RMGIC liner. The modified von Mises stresses (mvm) (MPa) were extracted on the nodes of the internal wall of the pulp ceiling chamber at 100 N occlusal loading. Data were analyzed descriptively and recorded quantitively. Both study factors influenced the stress distribution. The mvm stress during the restorative procedure was higher for nonselective carious tissue removal without RMGIC (25.9 MPa) and lower for selective carious tissue removal associated with RMGIC (13.5 MPa). The dentin elastic modulus increased from soft carious (3.6 ± 0.3 MPa) to firm carious (5.2 ± 1.0 MPa) to hard carious (10.9 ± 1.2 MPa) to intact dentin (22.7 ± 3.0 MPa). Molars with carious lesions showed high mvm stress at the pulp ceiling (89.6 MPa) and at fragilized coronal structure remaining. Selective carious tissue removal followed by restoration using a Vitrebond liner and Tetric N-Ceram Bulk fill reduced the stress at the pulp chamber ceiling.

Pain perception of children after restorative treatments: Atraumatic restorative treatment versus chemomechanical removal - A noninferiority randomized clinical trial.

Atraumatic restorative treatment (ART) and chemomechanical removal of dental caries have been shown to be safe and effective restorative procedures. However, current literature lacks well-design studies comparing the pain perceived by infants using ART and chemo-mechanical removal techniques. To compare pain perception of children of two techniques (ART vs. chemomechanical removal) of restorative treatments for dental caries removal. A randomized clinical trial with two parallels arms (1:1) was conducted in the cities of Manaus (AM) and Uberlândia (MG), Brazil. Children between 4 and 9 years old were selected. In both groups - ART (n = 20) and chemomechanical caries removal (Papaya® gel) (n = 20) - oximeter measurements (heart rate and blood oxygenation) were performed before the intervention and until the complete removal of the infected caries dentin. At the end of the treatment, a Wong-Baker scale was used to assess pain perception during the procedure. An independent researcher measured, in minutes, the duration of each technique. Poisson regression analysis was used to evaluate the association between the outcome and the explicative variables. No statistical difference in pain perception between the two procedures of carious tissue removal was observed. By contrast, a lower heart rate was observed when chemomechanical removal was used (P = 0.013). Children that underwent chemomechanical caries removal presented lower heart rate compared to those who underwent ART. However, both techniques showed minimal or absent perceived pain.

Pulp liner materials in selective caries removal: study protocol for a randomised controlled trial

IntroductionThe literature shows that selective carious tissue removal (SCTR) decreases the number and diversity of bacteria, stops the caries process and reduces the risk of pulp exposure. However, no consensus...

The use of Er:YAG Laser for dental caries removal

Background Carious tissue removal in enamel and dentin requires the use of sharp and resistant instruments. New tools have appeared to optimize/facilitate dental treatment, among them the laser. Regarding laser application for dental caries removal, the use of erbium laser doped with yttrium, aluminum, and garnet (Er:YAG) stands out. The Er:YAG laser is excellent for hard tissues ablation since its wavelength of 2.940nm is highly absorbed by water and hydroxyapatite. Objective To review the application of the Er:YAG laser in dental caries removal, to present its advantages and limitations in clinical practice, as well as to describe its action mechanism, and to compare its effectiveness with different methods used to remove caries. Data sources The search for articles to compose this literature review was carried out in the PubMed and Embase databases. Study selection Articles in English published between 2006 and 2021. The manual search included additional articles and books; a total of 39 references were selected. Data extraction Information from studies that evaluated the use of the Er:YAG laser to remove caries or related this type of laser to other methods. Articles that evaluated characteristics of the dental structure, or the influence of restorative materials after caries removal with the Er:YAG laser, were also considered. Study selection Based on studies results, the Er:YAG laser presents itself as an alternative for caries removal since it can remove demineralized tissue (selective ablation) without causing damage to the dental element.

MINIMALLY INVASIVE TREATMENT OF CARIOUS LESIONS IN PEDIATRIC DENTISTRY

Dificuldades no atendimento odontológico das crianças, devido à necessidade de controle do comportamento e de suporte familiar adequado, além de peculiaridades relativas à anatomia dos dentes decíduos, suscitam o uso de técnicas de mínima intervenção para o controle da cárie dentária. Logo, o objetivo do presente trabalho foi realizar uma revisão bibliográfica sobre o tratamento minimamente invasivo de lesões de cárie em dentes decíduos, abordando as características, indicações e limitações de diferentes técnicas dentro desse conceito. O controle de biofilme sem selamento dentário é uma abordagem na qual nenhum tipo de material restaurador é colocado para selar as cavidades, sendo instituída a higiene bucal de modo eficiente como estratégia para paralisar as lesões de cárie. O selamento da lesão sem remoção de tecido cariado prevê a utilização de selantes resinosos ou coroas metálicas diretamente sobre as cavidades, sem remoção prévia de tecido cariado. Já a remoção seletiva de cárie seguida de restauração é a técnica mais aceita e utilizada em odontopediatria, sendo atualmente considerado o padrão ouro, em detrimento da remoção total de tecido cariado. Apesar de a mínima intervenção ser bem aceita pelas crianças, sua aceitabilidade pelos responsáveis e odontopediatras ainda é questionável. Verificou-se que todas essas técnicas se apresentam como alternativas eficazes para o tratamento minimamente invasivo em odontopediatria. Entretanto, é fundamental o entendimento, participação e comprometimento dos familiares, tendo em vista que o controle do biofilme e da dieta possuem papel fundamental para garantir o sucesso desses tratamentos.

Antibacterial effect of a brominated self-etch adhesive on carious dentin - An in vivo study

ObjectivesThis in vivo study compared the antibacterial effect of a self-etch adhesive with and without the brominated monomer 12-methacryloyloxydodecyl-pyridinium bromide (MDPB) on carious dentin after selective caries removal. Methods10 patients showing deep primary carious lesions at two posterior teeth without pulpal symptoms were included. At visit I, carious tissue was selectively removed and carious dentin was sampled with a sterile roundbur (Komet No. 18). One cavity was restored with composite (SDR, Ceram X; DENTSPLY DeTrey) using an MDPB-containing self-etch adhesive (Clearfil Protect Bond, Kuraray Noritake; PB). The other restoration served as a control (Clearfil SE Bond II, Kuraray Noritake; SE). At visit II after 8 weeks, carious dentin was sampled again. Bacterial growth in carious dentin was differentiated using microbial cultivation. Bacterial DNA from intact cells and cell-free DNA were quantified using 16S rRNA gene-based real-time PCR and the microbial community composition was analyzed by amplicon deep-sequencing. Wilcoxon test was applied for statistical analysis. ResultsBoth treatments showed a decrease of intact bacterial cells in carious dentin at visit II compared to visit I (PB: visit I: 1.1*106, visit II: 1.7*105 (p = 0.03); SE: visit I: 1.1*107, visit II = 2.4*105 (p = 0.002)). No statistically significant reduction of cell-free bacterial DNA was detected (PB: visit I: 6.1*105, visit II: 1.6*105 (p = 0.08); SE: visit I: 5.3*105, visit II: 2.9*105 (p = 0.10)). The decrease of intact cell-derived (p = 0.371) and cell-free DNA (p = 0.455) did not differ significantly between PB and SE. Lactobacillus was most abundant within the microbial community at both visits. Alpha-diversity was not affected by treatment and samples showed high intra- and interindividual diversity. Conclusion and clinical significanceBoth self-etch adhesives have an antibacterial effect due to a decrease of bacterial DNA after selective caries removal. However, the results do not reveal any additional antibacterial effect by MDPB.The study is registered with the German Clinical Trials Register (DRKS00011532).

Pulp Vitality and Longevity of Adhesive Restorations Are Not Affected by Selective Carious Removal: A Multicenter Clinical Trial

The aim of this multicenter randomized clinical trial was to evaluate the pulp vitality and survival rate of adhesive restorations performed on posterior deciduous teeth after non-selective (NSCR) or selective (SCR) carious tissue removal over 33 months. One hundred and seven children (average age 4–8 years, SD 1.4) with at least two active moderate cavitated lesions in dentin were included. Teeth were randomized and submitted to NSCR or SCR before composite resin restoration. Restorations were clinically and radiographically assessed at baseline, 6, 12, 18, 24, and 33 months by a blinded, trained, and calibrated operator in each center. The characteristics of the restorations were recorded according to FDI criteria and were considered as restorative failures when scores 4 or 5 were presented. Pulp vitality was measured by clinical and radiographic examinations, and those teeth that presented any signs or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. Data were analyzed by a Cox regression model with shared frailty, considering two outcomes: pulp and restorative. A total of 278 restorations (137 after NSCR and 141 after SCR) were performed at baseline in four different centers and there was no loss in the follow-up period. Survival rate was 97.1 and 87.1% for pulp and for restorative outcome, respectively. The overall annual failure rate was 7%. There were no differences in the failure risk according to the treatment group, center, and all the clinical and demographic variables, regardless of outcome. Composite restorations of active moderate deep carious lesions performed on posterior primary teeth show satisfactory survival for restorative and pulp outcome after a 33-month follow-up, regardless of the technique executed for carious tissue removal.

Preliminary evaluation of a virtual reality dental simulation system on training of caries identification ability

OBJECTIVE To develop a software based on system which is a virtual reality dental simulation system and applied to undergraduate majoring in stomatology to improve the ability of identifying caries. METHODS A software was developed applying to identify virtual dental caries based on UniDental system. In the software, a virtual dental caries model was designed and carious tissue was separated to 3 layers by the depth. The stiffness was the same within each layer which was increasing gradually layer by layer. The roughness was also the same within each layer which was decreasing gradually layer by layer. Sixty-four participants in pre-clinical stage of the class of 2014 majoring in stomatology from Peking University School of Stomatology were trained with the software. During the training, the students should probe on the virtual dental carious tissue layer by layer and feel the difference of vertical stiffness and horizontal roughness of each layer by using a handpiece with realistic force feedback. After training, a questionnaire survey was conducted to evaluate the software including a score of 1-5 for haptic fidelity of stiffness and roughness and their relevant gradient and benefit of improving the ability of identifying caries, choosing the preferred training method. The data were statistically analyzed using Kruskal-Wallis test. RESULTS The median of subjective evaluation scores of the proposed metrics were all 4, demonstrating that the software operated above medium fidelity. The stiffness scores of all 3 layers were statistically significant (P < 0.05) on the stiffness gradient score. The roughness scores of the 1st and 2nd layers were statistically significant (P < 0.05) on the roughness gradient score. The training was helpful to improve the ability of identifying caries (median was 4). The scores of all 3 layers stiffness and relevant gradient were statistically significant (P < 0.05) on the score of benefit of improving the ability of identifying caries. 90.4% of the participants preferred the traditional extracted teeth training method. CONCLUSION The virtual reality dental simulation system was helpful to improve students' ability of identifying caries. It couldn't replace the traditional extracted teeth training method by now, it should be used as a supplement to the traditional training method.

The Efek Enzim Bromelin Buah Nanas (Ananas comosus (L.) Merr) Berbasis Sediaan Gel terhadap Lebar Intertubulus Dentin

Caries tissue cleaning can use Chemo-Mechanical Caries Removal (CMCR) based on proteolytic enzymes that catalyze peptide bonds into simpler compounds. Proteolytic enzymes can be found in mature pineapple bromelain enzymes. The aim of the study is to determine the effect of gel-based bromelain enzyme with concentrations of 8%, 10% and 12% against the width of the intertubulus dentin. The bromelain enzyme is extracted using the Lowry method. Then purified using 80% ethanol and diluting become to concentrations of 8%, 10% and 12%. Diluted bromelain enzymes were formed in gel preparations based on HPMC and applied to the study sample. The results of this study indicated a widening of the intertubulus dentin. This is indicated by the variation of the dentin intertubulus width &gt; 2µm. This widening occurs because the bromelain enzyme can hydrolyze collagen in intertubulus dentin in the absence of alpha-l-antitrypsin. Hydrolysis causes the breaking of hydrogen bonds in the triple helix- shaped tropocollagen to turn into strands of polypeptide chains. The bromelain enzyme with a concentration 10% is more effective than 8% and 12% because it is within the maximum speed limit of the enzyme so that the enzyme is saturated by its substrate and there is a difference in specific enzyme activity in each concentration.

An Intraoral OCT Probe to Enhanced Detection of Approximal Carious Lesions and Assessment of Restorations.

Caries, the world’s most common chronic disease, remains a major cause of invasive restorative dental treatment. To take advantage of the diagnostic potential of optical coherence tomography (OCT) in contemporary dental prevention and treatment, an intraorally applicable spectral-domain OCT probe has been developed based on an OCT hand-held scanner equipped with a rigid 90°-optics endoscope. The probe was verified in vitro. In vivo, all tooth surfaces could be imaged with the OCT probe, except the vestibular surfaces of third molars and the proximal surface sections of molars within a "blind spot" at a distance greater than 2.5 mm from the tooth surface. Proximal surfaces of 64 posterior teeth of four volunteers were assessed by intraoral OCT, visual-tactile inspection, bitewing radiography and fiber-optic transillumination. The agreement in detecting healthy and carious surfaces varied greatly between OCT and established methods (18.2–94.7%), whereby the established methods could always be supplemented by OCT. Direct and indirect composite and ceramic restorations with inherent imperfections and failures of the tooth-restoration bond were imaged and qualitatively evaluated. The intraoral OCT probe proved to be a powerful technological approach for the non-invasive imaging of healthy and carious hard tooth tissues and gingiva as well as tooth-colored restorations.

Atraumatic Restorative Treatment for Managing Dental Caries - A Review

The study aims to create awareness about the newly developing atraumatic treatment and its benefits.Atraumatic restorative treatment is an alternative treatment that is used for the removal of caries usinghand instruments only, so therefore no electricity or anaesthesia is required and the pain experienced isminimum. This technique is very useful for children, elderly, special needs patients and patients who feelfear and anxiety about dental treatment as in atraumatic restorative treatment that is more conservation oftooth structure, minimise in trauma and so there is reduced amount of pain due to small cavity preparations.Atraumatic restorative treatment is less painful and is more patient-friendly than that of conventional cariestreatment. The fundamental instruments for ART are mouth mirror, explorer, pair of tweezers, dental hatchet,small and medium-size excavator, spatula, amalgam carrier/applier. ART uses only hand instruments foropening/enlarging the cavity and for removing carious tissue. The amount of carious tissue that should beremoved depends mainly on the cavity depth. In cavities of shallow and medium depth, carious tissue isremoved up to firm dentine. In deep/very deep cavities, in which there is no sign of pulp exposure, pulpinflammation and/or history of spontaneous pain, some soft dentine can be left in the pulpal floor/wall toavoid pulp exposure. This method of treatment is more useful for people in underexposed areas where theyare also able to maintain good oral health.

Lasers in Endodontics- A Review of Literature

Lasers are commonly used to reshape our gums during root canal procedures and to kill bacteria. Applicationof lasers in dentistry has been increased due to its safety and effectiveness in dental treatments. Lasers havebeen used as coadjuvant treatment in endodontic therapy with respect to both low-intensity laser therapy(LILT) and high-intensity laser treatment (HILT) to improve clinical procedures’ success rate. The majorprocedures done with lasers in endodontics are dentin hypersensitivity, removal of carious tissues, toothpreparations, pulp capping or pulpotomy and also in root canal treatment.Lasers are often used to removemouth lesions and to soothe discomfort. A thorough literature search was performed using the databaselike Pubmed, google scholar, BioRxiv, MESH database using the keywords ‘light amplification device’and ‘Endodontics’ and also their types with no date and year restrictions.12 articles with similar data havebeen found which were analysed and have been included in this study. Talulation were done using googledocuments. The recent articles discussed in this study help us in gaining further knowledge about lasers andtheir usage in endodontics. The various methods of using lasers discussed in this article has been widelyused by dental practitioners with 100% success rate. So it has been concluded that lasers are well establishedinstruments. Upcoming research based on lasers are showing more benefits and ability to perform lessinvasive procedures with greater comfort of patients has led to the development of lasers in modern dentistryespecially in endodontics.

&lt;p&gt;Conservative Composite Resin Restoration for Proximal Caries – Two Case Reports&lt;/p&gt;

The paradigms of contemporary caries management have shifted to minimal intervention dentistry. Conservative restorative procedures are recommended to replace the complete removal of all carious tissues in the management of dental caries. This article reports two clinical cases of conservative restorations of proximal caries. Different conservative cavity designs and restorative techniques were performed in the two cases. Proximal caries in posterior teeth were prepared using the box-only preparation technique or the proximal tunnel preparation technique. The cavities were restored directly with resin composites. The advantages of using the box-only preparation with fissure sealant included the maximum conservation of tooth hard tissues and the prevention of unnecessary tissue removal in the occlusal surface. The tunnel preparation preserved the marginal ridge and protected the restored tooth from fracture. The filling of composites into the tunnel demonstrated a better marginal adaptation than other restorative materials. These two techniques allowed for the preservation of more healthy dental hard tissue compared with traditional techniques. Potential problems in the restoration included the high incidence of the inappropriate removal of dental hard tissue, damage of the vital pulp and the microleakage due to the polymerization shrinkage. The solutions to minimize the risk of these problems in the operative procedures were discussed.

Contemporary restorative ion-releasing materials: current status, interfacial properties and operative approaches.

Minimally invasive (MI) concepts in restorative dentistry in the year 2020 request from the practitioner not only a scientifically supported rationale for carious tissue removal/excavation and defect-oriented, biological cavity preparation, but also a deep understanding of how to ensure a biomechanically stable and durable restoration in different clinical situations by applying different restorative options. Bio-interactive materials play an increasingly relevant role, as they not only replace diseased or lost tissue, but also optimise tissue mineral recovery (among other properties) when used in restorative and preventive dentistry. Indeed, this is of certain interest in MI restorative dentistry, especially in those cases where gap formation jeopardises the integrity of the margins along resin composite restorations, causing penetration of bacteria and eventually promoting the formation of secondary caries. Recently, the interest in whether ion-releasing materials may reduce such biofilm penetration into margin gaps and reduce such a risk for development and propagation of secondary caries is growing significantly among clinicians and scientists. The aim of this article was to explore mechanisms involved in the process that allow mineral deposition at the interface between such materials and dentine, and to describe how conventional 'bioactive' restorative materials currently available on the market may benefit treatments in MI dentistry.

Selective vs stepwise removal of deep carious lesions in primary molars: 24\xa0months follow-up from a randomized controlled trial

ObjectivesFor well-defined deep (> 2/3 dentin extension) carious lesions, selective (SE) or stepwise (SW) carious tissue removals have been recommended, while there is limited comparative evidence for both. We compared SE and SW over 24 months in a randomized controlled trial.MethodsA two-arm superiority trial was conducted comparing SW/SE in primary molars without pulpal symptoms but well-defined deep lesions. Seventy-four children (1 molar/child) aged 3–9 years were recruited. In a first step, peripheral carious tissue was removed until hard dentin remained, while in proximity to the pulp, leathery dentin was left. An adhesive compomer restoration was placed and restorations re-examined after 6 months. In SW, re-entry and removal to firm dentin was conducted pulpo-proximally, followed by re-restoration. Molars were re-evaluated for a total of 24 months. Our primary outcome was success (absence of restorative/endodontic complications or pulp exposures). Secondary outcomes included total treatment and opportunity costs and restoration quality, assessed using modified USPHS criteria.ResultsAfter 24 months, 63 molars (31 SE, 32 SW) were re-assessed. Four failures occurred (2 exposures in SW; 2 pulpal complications in SE, 1 of them leading to extraction, p > 0.05). Restoration integrity was satisfying in both groups (USPHS A/B/C in 21/8/0 SE and 23/7/0 SW, p > 0.05). Treatment and opportunity costs were significantly higher in SW than SE (mean 171 ± 51 vs. 106 ± 90; p < 0.001).ConclusionsAfter 2 years, SE and SW showed similar efficacy for managing deep carious lesions in primary molars. The higher costs for SW should be considered during decision-making.Clinical significanceIn primary molars with well-defined deep carious lesions SE was less costly and similarly efficacious like SW. From a cost and applicability perspective, SW may need to be indicated restrictively, e.g., for very deep (> 3/4 dentin extension) lesions only.Trial registrationClinicalTrials.gov Identifier: NCT02232828

Bonding effectiveness of the universal adhesive on caries-affected dentin of deciduous teeth

The aim of this study was to investigate the bonding effectiveness of the universal adhesive on caries-affected dentin and normal dentin of deciduous teeth. We collected 12 extracted second deciduous molars with adjacent caries on one side. Each tooth was divided into two parts: the carious half was grouped into the caries-affected (CAD) group, whereas the other half was allocated to the normal dentin (ND) group. In the CAD group, carious tissue was removed using a slow-speed ball drill under the indication of the caries maker. In the ND group, dentin was prepared to the similarly deep level. The Single Bond Universal adhesive system using self-etch strategies was applied following the manufacturer's instructions. The defective area was filled with a resin composite Shofu Beautifil II Namer. Electron microscope observation indicated that CAD was partially demineralised and the surface was rougher than ND after acid etching. Transmission electron microscopy images of CAD showed that the hydroxyapatite platelets were distributed sparsely in strips, whereas normal dentin was intact. There was no significant difference between the CAD group and ND group in microtensile bonding strength and failure mode analysis (P > 0.05). What's more, the morphology of hybrid layer was similar in two groups. In conclusion, caries-affected deciduous tooth dentin can achieve similar bonding strength to normal dentin with the application of Single Bond Universal adhesive.