Comparing the effectiveness of caries arrest by micro-operative treatment to operative treatment: A 2-year randomized controlled clinical trial.

OBJECTIVES: To compare the effectiveness of caries arrest by micro-operative treatment (sealing) to operative treatment (flowable resin composite restoration) through a 2-year randomized controlled clinical trial. MATERIALS AND METHODS: A prospective randomized controlled trial was conducted among 7-9-year-old children. At baseline, 630 subjects were screened and 92 children who had at least one carious lesion classified as ICDAS 3 on the pit and fissure of first permanent molar were included. Then they were randomly assigned to the sealant group (73 lesions) and the flowable resin composite group (76 lesions) to receive the corresponding intervention. Lesions status in each group was evaluated every 6 months up to 24 months. Clinical progression of dental caries and materials retention were the outcomes used for group comparisons at p-value < 0.05. RESULTS: After 24 months, three lesions (4.1%) in the sealant group clinically progressed to dentin caries. No lesion in the flowable composite group was observed a progression. The results of Life-table survival analysis show that the cumulative caries arrest rate had no statistically significant difference between the two groups (p = 0.075). However, the cumulative retention rate was 57.5% in the sealant group and 92.1% in the flowable composite group, with significant differences (p < 0.001). The multilevel mixed model showed the sealant had higher risk of retention failure than the flowable composite (OR = 8.66, p < 0.001), while tooth position did not influence material retention (p = 0.083). In addition, the results of Fisher Exact test show that dentin lesions had more retention failure than enamel lesions in the sealant group (p = 0.026). CONCLUSION: Although sealing microcavitated carious lesions of the first permanent molar achieved lower retention rate than resin composite restoration, both sealing and restoration effectively arrested caries progression for two years. CLINICAL RELEVANCE: To preserving dental structure and delaying or eliminating the need for operative procedures, microcavitated carious lesion can be arrested by sealing. TRIAL REGISTRATION: Registered at http://www.chictr.org.cn ; Feb 15th, 2020; No. ChiCTR2000029862.

Elective full pulpotomy in mature permanent teeth diagnosed with symptomatic irreversible pulpitis: a two years retrospective study.

AIM: To investigate the outcome of elective full pulpotomy, using calcium silicate-based cements (CSBC), after 2 years, in symptomatic mature permanent teeth with carious lesions, diagnosed as irreversible pulpitis, and analyse the capacity of Wolters et al. (2017) classification to predict the likelihood of treatment failure. METHODS: The treatment records of 56 patients with symptomatic mature teeth with carious lesions, diagnosed as irreversible pulpitis and treated by elective full pulpotomy, using CSBCs as pulp capping materials, were reviewed. Thirteen teeth were excluded. The remaining 43 teeth were evaluated retrospectively at 24 months. Fisher`s exact test with the Lancaster's mid-P adjustment was used to assess different outcomes amongst the diagnostic categories. RESULTS: Four of the cases failed before 24 months and required root canal treatment (RCT). Overall success rate at 2 years was 90.7% (39 of 43). An inverse, but non-significant, correlation was observed between the severity of pulpitis according to the Wolters classification and the treatment success rate (p > 0.05). The type of CSBC used was associated to the success rate (OR = 10.5; 95% C.I. = 0.5 - 207.4; p = 0.027), being 82% with Endosequence and 100% with Biodentine. Postoperative pain associated significantly to lower success rate (66.7%) (Odds ratio = 8.0; 95% C.I. = 0.7 - 95.9; p = 0.047). CONCLUSIONS: Elective full pulpotomy using a CSBC was a successful choice for the treatment of mature permanent teeth with symptoms indicative of irreversible pulpitis. There were no significant differences between the success rate of mild, moderate and severe pulpitis. Postoperative pain could be considered a risk marker for failure of full pulpotomy. The term "irreversible pulpitis" should be re-signified to indicate the need for access to the pulp chamber, rather than an indication for extraction or RCT.

Comparative Meta-Analysis of Minimally Invasive and Conventional Approaches for Caries Removal in Permanent Dentition.

Background and Objectives: Addressing deep carious lesions poses significant challenges in daily dental practice due to the inherent complexity of their treatment. Traditionally, complete removal of carious tissues has been the norm, potentially leading to pulp tissue exposure and subsequent pulpitis. In contemporary dentistry, there is a growing preference for minimally invasive techniques, such as selective removal, offering a more conservative approach with enhanced predictability and success rates. Materials and Methods: Our study commenced with a comprehensive systematic review. After that, we performed a meta-analysis focused exclusively on randomized controlled trials involving permanent dentition. Our investigation incorporated seven selected articles, which scrutinized success rates and the incidence of pulp exposure in minimally invasive techniques (MIT) versus conventional techniques (CT). Statistical analysis employed U Mann-Whitney and Wilcoxon tests to interpret the results. Results: Although the difference did not reach statistical significance, MIT demonstrated marginally superior success rates compared to CT. Furthermore, MIT exhibited a lower percentage of pulp exposure when contrasted with CT. However, due to the limited sample size, statistical significance for this difference could not be established. Conclusions: Minimally invasive techniques for caries removal emerge as a conservative and promising approach to safeguard pulp tissues in comparison to conventional techniques. The need for additional randomized controlled trials is emphasized to unequivocally establish the superior success rates of these procedures over their conventional counterparts.

Assessing the Acceptability of Less Invasive Caries Removal Techniques for treating Deep Carious Lesions: A Conjoint Survey among Dentists Practicing in a Midwestern American State.

This study identified factors that influence dentists' decisions regarding less invasive caries removal techniques such as stepwise removal (SW) and selective removal (SE) using a marketing research technique, conjoint analysis. A survey was sent to 1,434 dentists practicing in Iowa. Dentists were randomly assigned to receive a questionnaire to rate the likelihood they would use either SW/SE in hypothetical clinical scenarios. The scenarios were carefully created by conjoint design and included three relevant attributes: depth of lesion, hardness of carious dentin, and patient age. Descriptive and conjoint analyses were performed to assess trade-offs between these attributes, using SPSS. The study revealed that depth of lesion was the most important factor in the dentists' decisions (49 importance value) when choosing a SW to treat a deep carious lesion, followed by hardness of carious dentin and patient age (21 importance value). For the SE group, depth of the lesion was also the predominant factor when selecting a treatment. The study also identified that a high proportion of dentists (24.9%) indicated they would never consider using SW or SE under any circumstances. Our survey showed that depth of lesion was the most important reason to select a less invasive caries removal method. The high proportion of dentists indicating they would never consider selective caries removal (SE) techniques suggests that these less invasive options are underutilized.

Impact of Medical and Surgical Obesity Treatment on Dental Caries: A 2-Year Prospective Cohort Study.

The objective was to study the long-term effects on oral health of bariatric surgery compared with medical treatment of obesity. Swedish females with morbid obesity (n = 66; 18-35 years at baseline) were followed prospectively from before obesity treatment until 2 years after treatment. The main response variable was dental caries registered according to the ICDAS-II system. Possible confounding factors, such as sociodemographic characteristics, general health, oral health habits, and oral hygiene, were controlled for. The statistical methods included χ2 tests, Student's t tests, one-way ANOVA, Wilcoxon's nonparametric tests, and linear regression models. In the surgically treated patients (n = 40), a significant increase over time in enamel caries (mean increase 4.13 tooth surfaces ICDAS1-2), dentine caries (mean increase 2.18 tooth surfaces ICDAS3-6), and total caries (mean increase 6.30 tooth surfaces ICDAS1-6) was registered (all p < 0.001), which was not seen in the medically treated patients (n = 26). However, the difference between the treatment groups (surgical or medical) was only statistically significant for enamel caries (crude ß 4.89, p = 0.003) and total caries (crude ß 6.53, p < 0.001). The relationships were stable and independent of differences in confounders as socioeconomy, general health, and oral health behaviors. In conclusion, 2 years after obesity treatment, a significant increase in dental caries was registered in the surgically treated but not in the medically treated women. The dental service should intensify its preventive efforts in individuals undergoing obesity treatment.

One-year outcome of selective caries removal versus pulpotomy treatment of deep caries: A pilot randomized controlled trial.

AIM: This study aimed to compare the outcome of SCR and Pulpotomy in teeth with deep caries extending at least 75% into dentine. METHODOLOGY: This two-armed, parallel-group, randomized, superiority trial included vital mature permanent teeth with deep primary or secondary caries diagnosed radiographically as being at least 75% into the thickness of dentine, without clinical signs of symptomatic irreversible pulpitis or radiographic evidence of a periapical lesion. Carious teeth were blindly allocated to receive either SCR or Pulpotomy using computer-generated randomized patient codes concealed in opaque envelopes. All teeth were reviewed clinically and radiographically at 6 months and 1 year post-treatment. Using a significance level of p < .05, the log rank test and Cox proportional hazards regression were used to compare the outcome of SCR and Pulpotomy and to identify potential prognostic factors, respectively. RESULTS: In all, 58 teeth in the SCR group and 55 teeth in the pulpotomy group completed treatment, after excluding 6 teeth because they did not complete the allocated treatment and another due to severe periodontal disease. At one year, 57/58 (98.3%) teeth from the SCR group and 48/55 (87.3%) teeth from the Pulpotomy group were available for analysis. One tooth in the Pulpotomy group (2.1%) and eight teeth in the SCR group (14.0%) required the further intervention of root canal treatment (p < .05). There were no other significant prognostic factors for survival. Overall, 91.4% of teeth treated with either SCR or Pulpotomy survived without requiring further intervention over a period of one year. No other adverse events occurred over the review period. CONCLUSION: Within the limitations of this study, Pulpotomy fares better than SCR in preserving the remaining pulp and periapical health. As a treatment modality, Pulpotomy carries greater cost outlay to patient and takes a longer time to complete treatment than SCR. Long-term follow-up is needed to study the pulpal and restorative outcomes of Pulpotomy and SCR.

Selective removal to soft dentine or selective removal to firm dentine for deep caries lesions in permanent posterior teeth: a randomized controlled clinical trial up to 2 years.

OBJECTIVES: The aim of this randomized clinical trial was to compare selective removal to soft dentin (SRSD) and selective removal to firm dentin (SRFD) in permanent teeth. The primary outcome of the study was to compare the success rates of the two caries removal techniques. The secondary outcome of the study was to investigate whether or not calcium silicate-based material (CS) had an effect on the success rate of the treatment. MATERIALS AND METHODS: Between November 2018 and March 2020, patients with deep caries lesions were invited to participate in the study. Posterior teeth (N = 165) with primary caries lesion radiographically extending ¾ of dentin and positive response to cold test were randomly selected. A total of 134 participants meeting the inclusion criteria were randomized to SRSD and SRFD (control) groups. After the caries removal procedure, teeth with exposed pulps were assigned to the pulp exposure (PE) group, and the SRSD group was further divided into test 1 (with CS) and test 2 groups (without CS). Success was defined as a positive response to the cold test, a negative response to percussion, the absence of pain, an abscess, a fistula, and periapical alterations. Fisher-Freeman-Halton exact tests, Kaplan-Meier survival analysis, and the log-rank tests were performed for comparisons between groups. RESULTS: No statistically significant difference was found between the success rates of test 1 (100%) and test 2 (93.5%) groups, whereas the proportion of success in control (82.4%) and PE (84%) groups were significantly lower when compared with test groups (p = 0.024; p < 0.05) at the end of 2-year follow-up. CONCLUSIONS: SRSD had a higher success rate when compared to SRFD to treat deep carious lesions after 2 years of follow-up. The use of CS material after SRSD as a liner had no effect on the treatment outcome. CLINICAL RELEVANCE: SRSD with good coronal sealing might be recommended without CS application for the treatment of deep caries lesions in permanent teeth. TRIAL REGISTRATION: Clinical trial registration number NCT04052685 (08/09/2019).

Level of difficulty of tooth extractions among roughly 100,000 procedures in primary care.

OBJECTIVES: The study examined treatment codes of extracted teeth and aimed to assess degree of difficulty concerning all tooth extractions. MATERIALS AND METHODS: Retrospective data on treatment codes of all tooth extractions during a two-year period were obtained from the patient register in primary oral healthcare of the City of Helsinki, Finland. Prevalence, indication, and method of extraction appeared in the treatment codes (EBA-codes). Degree of difficulty was determined from the method and classified as non-operative or operative and as routine or demanding. Statistics included frequencies, percentages, and χ2 test. RESULTS: Total number of extraction procedures was 97,276, including 121,342 extracted teeth. The most frequent procedure was a routine extraction of a tooth with forceps (55%, n = 53,642). The main reason for extraction was caries (27%, n = 20,889). Of the extractions, 79% (n = 76,435) were non-operative, 13% (n = 12,819) operative, and 8% (n = 8,022) multiple extractions in one visit. Level of difficulty was distributed as routine non-operative (63%), demanding non-operative (15%), routine operative (12%), demanding operative (2%), and multiple extractions (8%). CONCLUSIONS: Two-thirds of all tooth extractions in primary care were relatively simple. However, 29% of procedures were classified as demanding. CLINICAL RELEVANCE: As earlier methods for assessing level of difficulty were aimed at third molars alone, an analysis was presented for all tooth extractions. This approach may be useful for research purposes, and the profile of tooth extractions and their difficulty level may be practical also for decision-makers in primary care.

The Importance of Oral History: Does Dental Implant Placement or Caries One Year Before or After Primary Total Knee Arthroplasty Increase Medical Complications and Periprosthetic Joint Infections?

BACKGROUND: Consensus regarding prior dental problems on the outcomes of total knee arthroplasty (TKA) patients is lacking. Therefore, our objectives were to determine the association of dental caries or dental implant placement in TKA patients on the following: (1) medical complications; (2) health care utilization (lengths of stay and readmissions); (3) implant-related complications; and (4) expenditures. METHODS: A retrospective query was performed using an administrative claims database for 3 patient cohorts undergoing primary TKA from 2010 to 2020. Patients who had a history of dental caries or implant placement 1 year prior to TKA (n = 1,466) and 1 year after TKA (n = 1,127) were case-matched to patients who did not have a dental history by age and comorbidities. Outcomes included 90-day complications, health care utilization parameters, 2-year implant complications, and expenditures. Logistic regression models computed odds ratios (OR) of complications and readmissions. P values less than 0.005 were significant. RESULTS: Patients who had a dental implant placement prior to TKA had higher frequency of complications (20.05 versus 14.01%; OR: 1.53, P < .0001), including myocardial infarctions (2.52 versus 1.23%; OR: 2.08, P = .0002) and pneumonia (2.52 versus 1.24%; OR: 2.06, P = .0002). Lengths of stay (3.28 versus 2.98 days; P = .255), readmission rates (4.71 versus 4.28%; P = .470), and implant-related complications including periprosthetic joint infections (3.14 versus 2.63%; OR: 1.20, P = .279) were similar between patients lacking dental history. Expenditures were higher in patients who had a postoperative and preoperative dental history ($19,252 versus $19,363 versus 17,980; P < .001). CONCLUSION: Dental caries or implant placement may reflect overall worse medical condition resulting in more complications and higher costs after TKA. Dental history screening preoperatively may assist arthroplasty surgeons in minimizing complications.

Success of medicaments and techniques for pulpotomy of primary teeth: An overview of systematic reviews.

BACKGROUND: Pulpotomy is an effective, vital pulp therapy procedure for caries-affected or traumatized primary teeth. Though its efficacy is widely accepted, the superiority of medicaments and techniques remains debatable. AIM: The aims of this review were to compare the success rates of various pulpotomy medicaments or techniques, assess the methodological quality of reviews, and grade the level of evidence for each comparison. DESIGN: This review followed the principles of evidence-based medicine and recommendations for the overview of systematic reviews. An a priori protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42021244489). A comprehensive literature search was performed by two reviewers, and studies were selected from various databases according to predefined criteria. Two reviewers independently used a self-designed pilot-tested form to extract data from the selected studies. A quality analysis was performed using A MeaSurement Tool to Assess systematic Reviews-2 (AMSTAR-2) and the ROBIS tool. Reporting characteristics and overlap of the primary studies were also assessed. We used modified Köhler's criteria for evaluating the quality of evidence for outcomes of included systematic reviews and meta-analyses. RESULTS: The scrutiny of 62 full-text articles resulted in the inclusion of eight systematic reviews. The quality of four of the reviews was found to be critically low, and the overlap of primary studies in the meta-analyses was found to be high. Pulpotomy medicaments/techniques, except calcium hydroxide, had success rates of more than 80% for all domains and time periods. Most of the comparisons revealed no differences in the clinical, radiographic, or overall success rates. Mineral trioxide aggregate, however, was found to have better radiographic and overall success rates than calcium hydroxide at periods greater than 12 and 18 months. It also had a greater radiographic success rate than full-strength/1:5 diluted and full-strength formocresol at 24 months. Formocresol was found to have better overall success rates than calcium hydroxide at all time periods and better radiographic success rates at 12 months. Only 12 of the 63 comparisons had suggestive or weak evidence, whereas all others had either negligible evidence or insufficient data. CONCLUSIONS: The pulpotomy medicaments/techniques, except calcium hydroxide, showed success rates of more than 80%, whereas most comparisons revealed no differences. Mineral trioxide aggregate, however, was found to be better than calcium hydroxide and formocresol in several respects. This study highlights the lack of evidence regarding the choice of pulpotomy agents for the treatment of caries-affected primary teeth and elucidates the domains that require primary studies in the future.

Factors relating to failure rates of dental procedures in children following comprehensive dental treatments under general anesthesia: A 2-year retrospective study.

Background and Aim: This study assessed the demographic, treatment, and patient characteristics relating to 2-year postoperative failure and success rate of 2 to 12-years-old healthy children that underwent various dental procedures during comprehensive dental treatment under general anesthesia (GA). Materials and Methods: A retrospective study was conducted after the completion of a 2-year postoperative follow-up examination. The hospital records of all the children were reviewed by an experienced examiner. In the follow-up appointment, the clinical and radiographic evaluations of the treatments, oral hygiene, and oral hygiene practices were recorded. A P value of <0.05 was set as statistically significant. Results: Around 221 healthy children were included in the study, with a mean (SD) age of 4.92 (1.37). The most common type of failure detected 2 years postoperatively were recurrent decay (mean = 2.68, SD = 2.50), followed by stainless steel crown (SSC) open margin (mean = 0.69, SD = 1.02). Children with good oral hygiene involved the highest number of successful procedures (mean = 5.28, SD = 1.99) (P = 0.032). Children with poor oral hygiene was the factor that involved the highest number of procedure failures (mean = 8.28, SD = 3.38) (P < 0.001). The Pearson correlation coefficient showed that the younger the mean age of children during treatment under GA, the higher the rate of dental procedure failure (r = -0.202, n = 221, P < 0.01). Conclusion: The failure rate of dental procedures performed during treatment under GA was highest among younger children and children with poor oral hygiene at the time of treatment. SSC crown restoration was the most common type of dental procedure received, and recurrent decay and SSC open margin were the most common types of failure detected.

Dental pathologies in tumor patients with bone metastases or multiple myeloma scheduled for antiresorptive therapy.

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a potentially severe complication of mainly antiresorptive drugs. We evaluated the frequency of dentoalveolar pathologies in patients scheduled for antiresorptive therapy in a 'real-world' setting, also including patients with poor oral health potentially requiring tooth extractions and/or other dentoalveolar surgery. This approach is in contrast to the setting of recent randomized trials with restrictive exclusion criteria. Patients & methods: We prospectively included patients suffering from solid tumors with osseous metastases or multiple myeloma. Screening for dentoalveolar pathologies was done prior to initiation of antiresorptive therapy at the specialized MRONJ clinic of the University Hospital for Cranio-Maxillofacial and Oral Surgery, Innsbruck, Austria. Results: 119 subjects could be included. In 76 patients (63.9%), a dental focus was revealed including deep caries (24.4% of patients), chronic apical periodontitis (26.9%), periodontal disease (45.8%), root remnants (16%), jaw cysts (2.5%), partially impacted teeth (5.0%) and peri-implantitis (5.0%). Conclusion: Considering the high number of dentoalveolar pathologies (63.9%), systematic dental focus screening prior to initiation of antiresorptive therapy is of utmost importance to lower the risk for MRONJ.

Dynamic characterization of indocyanine green-assisted dental caries ablation with continuous diode laser using thermal imaging and fluorescence spectroscopy.

We describe the time-resolved thermal changes in indocyanine green (ICG)-assisted diode laser ablation of dental caries as a potential technique for painless treatment based on the selective photoabsorption and controlled photothermal ablation. Static ablation mode produced a higher temperature rise compared with scanning mode due to localized accumulation of heat. A temperature rise between 45-80 and 70-95 °C was obtained after 20 s that corresponded to 29 and 80 W cm-2, respectively. The temperature of the tooth surface increased by irradiation time, and it behaved linearly up to 70 °C at 29 and 80 W cm-2. A maximum ablation per area of about 0.3 and 0.45 mg cm-2 was achieved after 80 s exposure at 29 and 80 W cm-2, respectively. A statistically significant difference is observed in mean carious teeth weight at various exposure times between low and high irradiances. A thermal penetration depth of 0.8-9 mm is determined for 1-100 s of exposure time. The IR thermal imaging of ICG temperature as a function of exposure time showed a linear increase for 60 s beyond which it deviated. The laser-induced fluorescence spectroscopy indicated that the ICG quality can be altered during the course of irradiation, which in our case, it corresponded to ≈ 78% loss of signal within 23 min of exposure. The caries removal experiment was performed within 100 s corresponding to ≈ 7% loss. We believe that the application of the above-combined technique can be utilized as a monitoring device to control the ablation interaction process.

Does Preventive Care Reduce Severe Pediatric Dental Caries?

INTRODUCTION: Tertiary oral health services (caries-related surgery, sedation, and emergency department visits) represent high-cost and ineffective ways to improve a child's oral health. We measured the impact of increased Texas Medicaid reimbursements for preventive dental care on use of tertiary oral health services. METHODS: We used difference-in-differences models to compare the effect of a policy change among children (≤9 y) enrolled in Medicaid in Texas and Florida. Linear regression models estimated 4 outcomes: preventive care dental visit, dental sedation, emergency department use, and surgical event. RESULTS: Increased preventive care visits led to increased sedation visits (1.7 percentage points, P < .001) and decreased emergency department visits (0.3 percentage points, P < .001) for children aged 9 years or younger. We saw no significant change in dental surgical rates associated with increased preventive dental care reimbursements. CONCLUSION: Increased access to preventive dentistry was not associated with improved long-term oral health of Medicaid-enrolled children. Policies that aim to improve the oral health of children may increase the effectiveness of preventive dentistry by also targeting other social determinants of oral health.

Effect of CO2 laser (10.6 µm) and Remin Pro on microhardness of enamel white spot lesions.

This study investigated the combined effect of CO2 laser irradiation and Remin Pro paste on microhardness of enamel white spot lesions (WSLs). Seventy-eight intact premolars were randomly assigned into six groups and then stored in a demineralizing solution to create WSLs. Afterwards, the teeth in group 6 (negative control) remained untreated, while groups 1 and 4 were exposed to CO2 laser irradiation (20 Hz, 1 W, 30 s) and Remin Pro paste, respectively. In groups 2 and 3, the teeth were exposed to laser either before (group 2) or after (group 3) Remin Pro application. The teeth in groups 1 to 5 were then immersed in artificial saliva for 90 days while subjected to fluoride mouthwash and weekly brushing. Finally, the teeth were sectioned, and Vickers microhardness was measured at the enamel surface and at 50, 100, and 150 µm from the surface. One sample of each group was also examined with scanning electron microscope (SEM). Data were analyzed by two-way analysis of variance (ANOVA) and Tukey's test. The significance was set at 0.05. Laser irradiation followed by Remin Pro application (group 2) caused a significant increase in total WSLs' microhardness compared with laser alone (group 1) and control groups (P < 0.05). Microhardness at depths of 100 and 150 µm was also significantly greater in group 2 compared with those of group 3 and control groups (P < 0.05). Combined application of CO2 laser with Remin Pro paste, when laser is irradiated before the paste, is suggested for re-hardening of WSLs in deep layers of enamel.

In vitro CO2 9.3-µm short-pulsed laser caries prevention-effects of a newly developed laser irradiation pattern.

Caries prevention with different lasers has been investigated in laboratory studies and clinical pilot trials. Objective of this in vitro study was to assess whether 9.3-µm microsecond short-pulsed CO2 laser irradiation enhances enamel caries resistance without melting, with and without additional fluoride application. Seven groups of enamel, totaling 105 human enamel samples, were irradiated with 2 different carbon dioxide lasers with 2 different energy application systems (original versus spread beam; 9.3 µm wavelength, pulse repetition rate 43 Hz vs 100 Hz, fluence ranges from 1.4 to 3.9 J/cm2, pulse duration 3 µs to 18 µs). The laboratory pH-cycling was performed with or without additional fluoride, followed by cross-sectional microhardness testing. To assess caries inhibition, the mean relative mineral loss delta Z (∆Z) was determined. To evaluate for melting, scanning electron microscopy (SEM) examinations were performed. For the non-laser control groups with additional fluoride use, the relative mineral loss (ΔZ, vol% × µm) ranged between 512 ± 292 and 809 ± 297 (mean ± SD). ΔZ for the laser-irradiated samples with fluoride use ranged between 186 ± 214 and 374 ± 191, averaging a 58% ± 6% mineral loss reduction (ANOVA, P < 0.01 to P < 0.0001). For the non-laser-treated controls without additional fluoride, the mineral loss increased (ΔZ 914 ± 422 to 1224 ± 736). In contrast, the ΔZ for the laser-treated groups without additional fluoride ranged between 463 ± 190 and 594 ± 272 (P < 0.01 to P < 0.001) indicative of 50% ± 2% average reduction in mineral loss. Enhanced caries resistance was achieved by all applied fluences. Using the spread beam resulted in enhanced resistance without enamel melting as seen by SEM. CO2 9.3-µm short-pulsed laser irradiation with both laser beam configurations resulted in highly significant reduction in enamel mineral loss. Modifying the beam to a more homogenous profile will allow enamel caries resistance even without apparent enamel melting.

Laser-assisted prevention of enamel caries: a 10-year review of the literature.

Since the invention of lasers in dentistry, investigations in caries prevention by the use of laser radiation have been proposed. There are several mechanisms stated for this purpose such as photothermal and/or photochemical interaction processes with the enamel. Alone or in conjugation with topical fluoride application, this treatment modality may improve enamel acid resistance in high-caries-risk populations. Data collection was done by searching the keywords caries, prevention, and laser in PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar. Lasing protocols of the collected literature and their effectiveness as well as examination methods used to verify treatment outcomes have been evaluated. One hundred eighteen publications were found for the last 10 years. The wavelengths investigated for caries prevention are mainly located in the near and the mid-infrared spectral range. In the evaluated period of time, investigations using CO2; Er:YAG; Er,Cr:YSGG; Er:YLF; fundamental, second, and third harmonic generations of Nd:YAG; diodes; and argon ion lasers were found in the databases. Accounting for 39% of the literature, CO2 laser was the most examined system for this purpose. Reviewing the literature in this narrative review showed that all laser systems presented a positive effect in varying degrees. Laser irradiation could be an alternative or synergistic to topical fluoridation for enamel caries prevention with longer lasting effect. Further research should be focused on selecting proper laser settings to avoid damage to enamel and developing effective evidence-based clinical protocols.

Dental cavity liners for Class I and Class II resin-based composite restorations.

BACKGROUND: Resin-based composite (RBC) is currently accepted as a viable material for the restoration of caries for posterior permanent teeth requiring surgical treatment. Despite the fact that the thermal conductivity of the RBC restorative material closely approximates that of natural tooth structure, postoperative hypersensitivity is sometimes still an issue. Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure. This is an update of the Cochrane Review first published in 2016. OBJECTIVES: The objective of this review was to assess the effects of using dental cavity liners in the placement of Class I and Class II resin-based composite posterior restorations in permanent teeth in children and adults. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 12 November 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 10) in the Cochrane Library (searched 12 November 2018), MEDLINE Ovid (1946 to 12 November 2018), Embase Ovid (1980 to 12 November 2018) and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 12 November 2018). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We included randomized controlled trials assessing the effects of the use of liners under Class I and Class II posterior resin-based composite restorations in permanent teeth (in both adults and children). We included both parallel and split-mouth designs. DATA COLLECTION AND ANALYSIS: We utilized standard methodological procedures prescribed by Cochrane for data collection and analysis. Two review authors screened the search results and assessed the eligibility of studies for inclusion against the review inclusion criteria. We conducted risk of bias assessments and data extraction independently and in duplicate. Where information was unclear we contacted study authors for clarification. MAIN RESULTS: Eight studies, recruiting over 700 participants, compared the use of dental cavity liners to no liners for Class I and Class II resin-based composite restorations.Seven studies evaluated postoperative hypersensitivity measured by various methods. All studies were at unclear or high risk of bias. There was inconsistent evidence regarding postoperative hypersensitivity (either measured using cold response or patient-reported), with a benefit shown at some, but not all, time points (low-quality evidence).Four trials measured restoration longevity. Two of the studies were judged to be at high risk and two at unclear risk of bias. No difference in restoration failure rates were shown at 1 year follow-up, with no failures reported in either group for three of the four studies; the fourth study had a risk ratio (RR) 1.00 (95% confidence interval (CI) 0.07 to 15.00) (low-quality evidence). Three studies evaluated restoration longevity at 2 years follow-up and, again, no failures were shown in either group.No adverse events were reported in any of the included studies. AUTHORS' CONCLUSIONS: There is inconsistent, low-quality evidence regarding the difference in postoperative hypersensitivity subsequent to placing a dental cavity liner under Class I and Class II posterior resin-based composite restorations in permanent posterior teeth in adults or children 15 years or older. Furthermore, no evidence was found to demonstrate a difference in the longevity of restorations placed with or without dental cavity liners.

Selective ablation of dental caries using coaxial Co2 (9.3-µm) and near-IR (1880-nm) lasers.

OBJECTIVE: The purpose of this study was to determine the feasibility of image-guided laser ablation of demineralization from tooth occlusal surfaces using coaxial near-infrared (NIR) and CO2 lasers. MATERIALS AND METHODS: A CO2 laser operating at a wavelength of 9.3-µm was combined with a thulium-doped fiber laser operating at 1880-nm for the selective removal of simulated occlusal caries lesions from 10 tooth samples. Serial NIR reflectance images at 1880-nm were used to guide the CO2 laser for image-guided laser ablation. Polarization-sensitive optical coherence tomography (PS-OCT) was used to assess the initial depth of the lesions before removal and assess the volume of sound and demineralized tissue removed by the CO2 laser. RESULTS: PS-OCT scans indicated that roughly ∼99% of the lesion was removed by image-guided laser ablation. A mean volume of 0.191-mm3 or 11.9-µm/voxel of excess enamel was removed during lesion removal. CONCLUSION: A co-aligned NIR/CO2 laser scanning system has great potential for the highly selective removal of dental decay (demineralization). Lasers Surg. Med. 51:176-184, 2019. © 2018 Wiley Periodicals, Inc.

Qualitative evaluation of hybrid layer formation using Er:YAG laser in QSP mode for tooth cavity preparations.

The purpose of this study was to evaluate the thickness and qualitative characteristics of the hybrid layer after two cavity preparation methods, using Er:YAG laser in QSP mode and conventional carbide burs. Additionally, two different adhesive techniques were investigated using etch-and-rinse and self-etch adhesive systems. Sixty sound human third molars were used and were randomly divided into four groups (n = 15). In the first two groups, large (4 mm length, 3 mm wide, and 3 mm deep) class I cavities were prepared using Er:YAG laser (2.94 µm) in QSP mode, while in the other two groups, the cavities were prepared using carbide burs. After cavity preparations, two different adhesive techniques with GLUMA® 2 Bond (etch-and-rinse) and Clearfil™ Universal Bond Quick (self-etch) were applied. For the qualitative evaluation of the formed hybrid layer, photomicrographs were taken using SEM, and elemental semi-quantitative analysis was performed using EDS to confirm the extent of the hybrid layer. One-way ANOVA was applied to verify the existence of statistically significant differences, followed by Tukey test for post hoc comparisons (Bonferroni corrected), and the level of significance was set at a = 0.05. The laser-treated groups exhibited higher hybrid layer thickness than bur-treated groups (p < 0.001). Between the laser-treated groups, etch-and-rinse technique presented higher hybrid layer thickness than self-etch technique (p < 0.001), while between the bur-treated groups, no significant differences were detected (p = 0.366). Er:YAG laser cavity preparations in QSP mode may be advantageous for adhesion of composite restorations, but more data are necessary to confirm its clinical effectiveness.