Effects of 9,300 nm Carbon Dioxide Laser on Dental Hard Tissue: A Concise Review

Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate, Proanthocyanidin, Carbon Dioxide Laser Remineralization on the Bond Integrity of Composite Restoration Bonded to Caries Affected Dentin

Objective: Assessment of different remineralizing pretreatment casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), proanthocyanidin (PA), carbon dioxide laser (CO2), eggshell solution (ES) on the shear bond strength (SBS) of resin composite bonded to remineralized carious-affected dentin (CAD). Materials and methods: Eighty human molars were collected with occlusal caries that extended about halfway into the dentin. Using a water-cooled, low-speed cutting saw, a flat, mid-coronal dentin surface was exposed. CAD was differentiated from healthy dentin. Based on the remineralizing agent used on the CAD surface, the teeth were arbitrarily allocated into five groups (n = 10). Group 1: no remineralizing agent, Group 2: CPP-ACP, Group 3: 6.5% PA solution, Group 4: CO2 laser, and Group 5: ES solution. All samples were bonded to composite and light cured and thermocycled. SBS and failure mode analysis were performed using universal testing and stereomicroscope 40 × . Using SPSS, SBS, and failure mode data were analyzed using analysis of variance and Tukey's honesty significant difference (HSD) test Results: Group 3 (6.5% PA solution; 15.59 ± 1.44 MPa) samples established the maximum bond integrity. Nevertheless, Group 1 (No remineralizing agent; 11.19 ± 1.21 MPa) exhibited the minimum outcome of bond strength. Intergroup comparison analysis showed that Group 1 (No remineralizing agent), Group 2 (CPP-ACP), and Group 4 (CO2 laser) established comparable values of bond strength (p > 0.05). Likewise, Group 3 (6.5% PA solution) and Group 5 (EA solution) also revealed equivalent bond integrity (p > 0.05). Conclusions: PA and ES are considered potential remineralizing agents used for caries-affected dentin surfaces in improving bond integrity to composite resin. However, further studies are advocated to extrapolate the findings of this study.

Automation in Dentistry with Mechanical Drills and Lasers for Implant Osteotomy: A Narrative-Scoping Review

The popularity of implants is increasing with the aging population requiring oral-dental rehabilitation. There are several critical steps in the implant workflow, including case selection, implant design, surgical procedure, biological tissue responses, and functional restoration. Among these steps, surgical osteotomy procedures are a crucial determinant of clinical success. This brief review was aimed at outlining the current state of the field in automation-assisted implant surgical osteotomy technologies. A broad search of the literature was performed to identify current literature. The results are outlined in three broad categories: semi-automated static (image-guided) or dynamic (navigation-assisted) systems, and fully-automated robotic systems. As well as the current mechanical rotary approaches, the literature supporting the use of lasers in further refinement of these approaches is reviewed. The advantages and limitations of adopting autonomous technologies in practical clinical dental practices are discussed. In summary, advances in clinical technologies enable improved precision and efficacious clinical outcomes with implant dentistry. Hard-tissue lasers offer further advancements in precision, improved biological responses, and favorable clinical outcomes that require further investigation.

Effects of a 445 nm diode laser and silver diamine fluoride in preventing enamel demineralisation and inhibiting cariogenic bacteria

OBJECTIVE

To study the effects of a 445 nm diode laser (L) and silver diamine fluoride (F) on preventing enamel demineralisation and inhibiting cariogenic bacteria.

METHODS

Thirty-three enamel slices were sectioned each into four blocks for four groups to receive L with F (LF), F, L and Water (W, control). Ten blocks from each group were used to evaluate demineralization. Surface morphology, lesion depth and nanohardness of the blocks after pH-cycling were studied by scanning electron microscopy (SEM), nanohardness test, and micro-computed tomography, respectively. Twenty-three blocks per group were used for biofilm assessment. Morphology, viability, and growth kinetics of the Streptococcus mutans biofilm were assessed by SEM, confocal laser scanning microscopy, and the counting of colony-forming units (CFUs), respectively.

RESULTS

SEM images of LF-treated enamel showed an intact surface compared with other groups. Nanohardness (GPa) for LF, F, L and W were 1.43±0.17, 1.01±0.11, 1.04±0.13 and 0.73±0.14, respectively (p<0.001; LF>F, L>W). Their lesion depths (µm) were 46±8, 52±6, 88±13 and 111±9, respectively (p<0.001; LF, F<L<W). SEM showed few bacteria for LF and F compared with other groups. Their dead-live ratio were 1.67±0.13, 1.60±0.15, 0.39±0.05 and 0.32±0.05, respectively (p<0.001; LF, F>L>W). Log CFUs for LF, F, L and W were 4.2±0.3, 4.5±0.2, 7.9±0.3 and 9.4±0.2, respectively (p<0.05; LF<F<L<W). Two-way ANOVA analysis revealed an interaction effect on nanohardness and Log CFUs between the laser irradiation and SDF treatment (p<0.001).

CONCLUSION

This study showed a superior caries preventive effect of a combined treatment of the diode laser and SDF. Because diode laser and SDF are affordable and readily available, clinicians can provide this treatment to their patients for caries prevention.

CLINICAL SIGNIFICANCE STATEMENT

Diode lasers are handy, afforable and readily avaliable to clinicians. This study provides information of use of 445 nm diode laser for caries prevetion. The laser irradiation hopefully can be added before conventional topical SDF application.

Combined Effects of Topical Fluorides and Semiconductor Lasers on Prevention of Enamel Caries: A Systematic Review and Meta-Analysis

Objective: To compare the effects of combined treatment of topical fluoride and semiconductor laser (F&L) with topically using fluoride (F) on remineralization and prevention of enamel caries. Background: There is no agreement on whether semiconductor lasers can promote the effect of topical fluoride on the remineralization and prevention of dental caries. This study is the first systematic review and meta-analysis to investigate the pooled effect of data from studies that compared the combined use of semiconductor lasers and topical fluorides with the single use of fluoride on remineralization and prevention of caries. Methods: We performed literature search on Scopus, Web of Science, and PubMed. The keywords were as follows: ((diode lasers) OR (diode laser) OR (quantum cascade laser) OR (quantum cascade lasers) OR (Gallium Aluminum Arsenide lasers) OR (Gallium Aluminum Arsenide laser) OR (GaAlAs lasers) OR (GaAlAs Laser) OR (semiconductor laser) OR (semiconductor lasers)) AND ((caries) OR (dental caries) OR (remineralisation) OR (remineralization) OR (demineralization) OR (demineralisation)) AND fluoride. We carried out meta-analysis to compare the microhardness of demineralized enamel, lesion depth (LD), and percent reduction of calcium (Ca%) of sound enamel receiving F&L with F. Results: The search identified nine laboratory studies, which used 445 to 980 nm semiconductor lasers with various fluorides. The standard mean difference of microhardness of demineralized enamel between F&L and F was 1.06 [95% confidence interval (CI): 0.12 to 2.00, p = 0.03]. No difference was found in LD (95% CI: -1.63 to 0.10, p = 0.08) and Ca% (95% CI: -0.52 to 1.28, p = 0.40) on sound enamel between the two groups. Conclusions: Semiconductor lasers enhance the effect of fluoride on remineralizing but not on preventing enamel caries. Moreover, substantial heterogeneity was found among the studies, and the results should be interpreted cautiously.