A comparison of ceramic crown color difference between different shade selection methods: Visual, digital camera, and smartphone.

STATEMENT OF PROBLEM: The light source stability of digital cameras and smartphones is important in shade matching in restorative and prosthetic dentistry to communicate objectively with the dental laboratory. Techniques that standardize the light source of such devices are lacking, and this limitation can lead to color mismatches, difficulties in color communication, and treatment documentation. PURPOSE: The purpose of this clinical study was to compare the magnitude of color difference (ΔE) among 3 shade selection methods during the fabrication of ceramic crowns: visual shade selection with a shade guide, digital shade selection with a digital camera and cross-polarizing filter, and digital shade selection with a smartphone and a light-correcting device. MATERIAL AND METHODS: Forty-five patients in need of ceramic crowns were enrolled, and shade selection was evaluated according to different protocols: visual shade selection (A-D shade guide and IPS Natural Die Material Shade Guide, sent to the dental laboratory technician via a laboratory prescription); digital shade selection with a digital camera (D7000; Nikon Corp) with an 85-mm lens and wireless close-up flash, with and without a cross-polarizing filter (Polar eyes); and digital shade selection with a smartphone and a light-correcting device (iPhone XS attached to Smile Lite MDP, with and without its cross-polarizing filter accessory). Information from the smartphone was imported to an app (IPS e.max Shade Navigation App; Ivoclar AG) that converted the reading to a shade and level of translucency for the ceramic restoration. For all photographs, a gray reference card with known color values was positioned by the mandibular teeth and was used for white balancing of the digital photographs with a software program. All photographs were edited and sent to the dental laboratory: white-balanced with the shade guide; white-balanced with the substrate shade guide; black and white; saturated; and cross-polarized. Ceramic crowns were made with the same lithium disilicate material (IPS e.max CAD; Ivoclar AG) and cemented with the same resin cement (RelyX Ultimate Clicker, A3 shade; 3M). The ΔE values between the crown and the adjacent tooth were determined. The data were analyzed by using a 1-way analysis of variance (ANOVA) and Tukey post hoc tests (α=.05). RESULTS: The mean ΔE between a cemented ceramic crown and the adjacent tooth in the visual shade selection group was 5.32, significantly different than both digital camera (ΔE=2.75; P=.002) and smartphone (ΔE=2.34; P=.001), which were not different from each other (P=.857). CONCLUSIONS: The digital shade selection with photographs acquired with both a digital camera and a smartphone with a light-correcting device showed a threshold within the acceptable values (ΔE<3.7), whereas the visual shade selection showed an average ΔE above the threshold for acceptable values (ΔE>3.7). The use of a gray reference card helped standardize the white balance from the digital images.

Comparison of visual analog shade matching, a digital visual method with a cross-polarized light filter, and a spectrophotometer for dental color matching.

STATEMENT OF PROBLEM: During the selection of tooth color, subjective communication with the laboratory and an incorrect color registration technique can lead to a poor color match of a restoration to adjacent teeth and oral structures. PURPOSE: The purpose of this cross-sectional study was to compare color registration and color matching in a young Chilean population with 3 different methods: visual with a shade guide, digital visual with a cross-polarized filter, and instrumental with a spectrophotometer. MATERIAL AND METHODS: A total of 60 young volunteers were selected for tooth color registration of the maxillary right central incisor by using 3 different methods. Tooth color registration was performed using the CIELab and ΔE coordinate system. RESULTS: Significant differences were detected between the coordinates recorded by the visual analog method in comparison with the other 2 methods. In contrast, no significant differences were found between the L∗ and b∗ coordinates of the spectrophotometer and the digital visual method with use of a cross-polarization filter. The ΔE obtained between the visual shade and spectrophotometer was 7.35, and the ΔE between the digital visual method with the use of a cross-polarization filter and the spectrophotometer was 6.12. CONCLUSIONS: No statistically significant differences were observed in the digital image with the cross-polarization filter and the spectrophotometer in the L∗ and b∗ coordinate of the CIELab system. In contrast, the visual analog method led to large differences with the other methods under study. The ΔE of the digital visual method with the use of cross-polarization filters and the spectrophotometer was 6.2, considered as an acceptable color mismatch (<ΔE 6.8).

The biological effects of Piezocision™ on bone for accelerated tooth movement: A systematic review of animal studies.

OBJECTIVES: This systematic review aimed to assess the biological response at tissue, cellular, and molecular levels following Piezocision™ surgery, and its efficacy in accelerating orthodontic tooth movement. MATERIAL AND METHODS: A systematic review of the literature was conducted across 4 databases following the PRISMA guidelines up to May 2022. Prospective controlled animal studies involving healthy animals under active orthodontic treatment assisted by corticotomy performed with a piezotome (Piezocision™) published in the English language without time restrictions were included. The article selection, data extraction and risk of bias assessment (SYRCLE tool) were performed by two independent blinded review authors. RESULTS: Out of 738 articles screened, 10 studies were included with various level of bias. Biological responses were categorized into tissue, cellular, and molecular levels. Tissue-level changes included a global decrease in bone mineral content post-Piezocision™. At the cellular level, increased bone turnover activity was noted. Molecularly, elevated RANKL and OPG expression, along with increased TRAP+ and cytokines, were observed after Piezocision™. Studies confirmed Piezocision's efficacy, reporting 1.35 to 3.26 times faster tooth movements, peaking between the 3rd and 50th day post-surgery. Biological responses were transient, reversible, and proportional to surgical insult, with reactivation possible through a second Piezocision™. CONCLUSIONS: After Piezocision™ surgery, a transient and reversible biological response was described at the tissue, cellular and molecular levels, which induced faster orthodontic tooth movements. This biological response could be re-activated by an additional Piezocision™ and is proportional to the surgical injury. SYSTEMATIC REVIEW REGISTRATION: Prospero CRD42022303237.

Piezocision Through Computer-Guided Navigation.

Numerous surgical techniques have been developed as effective means to facilitate orthodontic treatment, although they may cause significant postoperative discomfort. Piezocision was established as a flapless and minimally invasive technique to accelerate orthodontic tooth movement by combining small vertical incisions and piezoelectric corticotomies. Computed tomography has been combined with the piezocision technique to fabricate computer-aided design and computer-aided manufacturing (CAD/CAM) surgical guides to prevent iatrogenic damage. A method to combine computer-assisted dynamic navigation with piezocision is introduced here. Cone-beam computed tomography was combined with motion-tracking technology to allow real-time tracing of the piezoelectric instruments during the surgical procedure. This technique delivers the location of piezoelectric knife in regard to roots and important anatomical structures to increase the safety and accuracy during corticotimies.

Artificial Intelligence Chatbots in Patient Communication: Current Possibilities.

ChatGPT, an artificial intelligence (AI) chatbot can generate text prompts based on user input. This study investigated the possibility of generating adequate and relevant patient education and management documents in the context of dental implant surgery utilizing this tool. METHODS: Twenty-seven (n=27) periodontists were surveyed on the accuracy and usefulness of AI-generated documents comprising patient information handouts on surgical risks and post-operative instructions sheets for dental implant placement either in smokers or patients with diabetes. They were also asked in a blinded fashion about their preferences between the generic dental implant placement consent form currently used at Boston University and two AI-generated consent forms: one generic and one tailored to patients with diabetes. RESULTS: A vast majority of participants found that the information in the AI-generated forms was accurate, useful and would feel comfortable using them with their own patients. The AI-generated generic consent performed as least as well as the human-written one, while the personalized informed consent for patient with diabetes performed significantly better (p<0.001). CONCLUSIONS: Within the limitations of this study, ChatGPT was able to independently generate accurate and useful patient information and management documents.

Quantification and comparison of the regional acceleratory phenomenon in bone following piezosurgery or bur osteotomy: A pilot study in rats.

BACKGROUND/OBJECTIVE: The Regional Acceleratory Phenomenon (RAP) can be induced surgically via decortication (selective cortical penetrations) of bone to accelerate orthodontic tooth movement. Few studies have compared the impact and efficiency of different decortication methods to induce the RAP. The aim of this study was to determine if there is a significant difference in the intensity of the RAP induced by a surgical defect created either using a piezoelectric knife or a rotary bur. METHODS: Twenty-two Sprague-Dawley rats were divided into two treatment groups (each n = 8) and a control group (n = 6). The treatment groups were subjected to transcortical penetrations (TP) of the right tibia using either a piezoelectric knife (PTP) or a rotary bur (BTP). The right tibias of the control group animals had reflection of tissues (SHAM) and the left legs were kept for comparison (INTACT). The animals were killed at 7 and 14 days after the operation in an equally distributed manner. Microcomputed tomography images were obtained and analyzed utilizing artificial intelligence for bone cortical porosity (Ct.Po) locally and regionally. RESULTS/CONCLUSION: Regionally, TP using a PTP induced significantly (p < .05, Kruskal-Wallis test) more Ct.Po than BTP or INTACT for both the 7- and 14-day time points. PTP was not found to induce significantly more Ct.Po than SHAM at any time point. However, PTP induced significantly more Ct.Po than the INTACT group for each time point, while SHAM did not. The local analysis did not reveal any relevant significant differences between groups.

Optical accuracy assessment of robotically assisted dental implant surgery for partially edentulous patients: a single arm clinical trial.

PURPOSE: To quantify the clinical accuracy of a robotically assisted implant guidance system in partially edentulous patients without the use of postoperative cone-beam radiography. MATERIALS AND METHODS: A total of 10 implants (7 patients) were placed in partially edentulous patients utilizing robotically assisted implant guidance system. Following the implant placement a intraoral scan was performed to register the implant position after attaching a scan body. The virtual plan and the postoperative intraoral scan with the scan bodies were exported as STL files, superimposed and discrepancies were analyzed using Geomagic Control X software. Positional deviations were measured between the midpoint of the platform and apex of the planned and achieved implant positions. RESULTS: Seven of the 10 samples in this study were defined as fully robotically dynamically guided, while 3 were partially robotically guided. For the fully robotic dynamically guided group the mean deviation at the midpoint of the restorative platform of the implant, the apex of the implant, the top of the scanbody, and the mean angular deviation were 1.31mm (SD0.46mm), 1.58mm (SD0.61mm), 1.11mm (SD0.57mm), and 2.34 degrees (SD1.71°), respectively. While for the partially robotic dynamically guided cases it was 1.31mm (SD0.49mm), 1.45mm (SD0.3mm), 1.74mm (SD0.47mm), and 3.75 degrees (SD2.53°). Eight out of the 10 implants (irrespective of full or partial guidance) showed a buccal displacement. CONCLUSION: Robotic surgery offers a level of accuracy similar to fully guided implant placement, without the need for a physical template, and allowing for changes in the surgical plan at any time. The analytical method described in this study is an effective and radiation free quality control tool that can be used in implant dentistry as well as in other areas of dental research dentistry.

Assessment of Maxillary Expansion by Piezocision-Assisted Orthodontics: A Pilot Study.

The correction of transverse malocclusions due to maxillary width deficiency in adults is challenging. Multiple surgical and nonsurgical procedures have been used in conjunction with orthodontics to address this situation, and most common is the surgically assisted rapid maxillary expansion (SA-RME). Although successful, it is quite aggressive. The present investigation assesses the usefulness of Piezocision-assisted orthodontics as a less-invasive option for treatment of transverse maxillary deficiencies in adults. Dental casts were taken before and after Piezocision-assisted palatal expansion in four patients. They were digitized into STL files and superimposed. Differences on cross-arch tooth torque, angulation/tipping, and movement distances between time points were quantified using a digital static and a novel digital 3D-movement evaluation method. For the buccolingual movement per tooth, first premolars averaged 3.33 ± 1.3 mm, second premolars averaged 3.63 ± 0.6 mm, and first and second molars averaged 1.56 ± 1.2 mm and 0.36 ± 1.2 mm, respectively. Bodily movement of the teeth was observed with minimal tipping and no development of gingival recessions. Piezocision-assisted palatal expansion is a safe and reliable procedure that can help patients with maxillary width deficiency. It is a new tool in the orthodontist's armamentarium that can be used as an accelerator of treatment and as a new way to solve orthodontic challenges in selected adult patients.

Corticotomy depth and regional acceleratory phenomenon intensity.

OBJECTIVES: To determine if the depth of corticotomy done with the piezoelectric knife could play a role in the intensity of the regional acceleratory phenomenon (RAP). MATERIALS AND METHODS: Eighteen Sprague-Dawley rats were divided into two groups: untreated (3 rats) and treatment (15 rats). In the treatment group, a split-model design was used. The right tibia received transcortical (deep) penetrations with the piezoelectric knife, while intracortical (shallow) penetrations were performed on the left tibia of the same animal. The rats were euthanized at day 1, 3, 7, 14, and 28. Cone-beam computed tomography scans were taken for each sample and then assessed by histological analysis. RESULTS: Higher amounts of osteoclastic activity and new collagen formation were observed in the deep penetration group when compared with the shallow penetration group. The former peaked at day 14 for both groups (1.53% ± 0.01% vs 0.03% ± 0.0004%, respectively), and the latter peaked at day 28 (0.65 × 106 ± 0.01 vs 0.08 × 106 ± 0.0008, respectively). CONCLUSIONS: Within the limitations of this study, it appears that the intensity of the RAP in the rat is corticotomy depth dependent. This is to be kept in mind when decorticating the bone during surgically facilitated orthodontic procedures.

Association between the use of statins and periodontal status: a review

ABSTRACT: Background: Statins are drugs used for the treatment of dyslipidemia. However, statins have multiple actions, including anti-inflammatory and immunomodulatory effects, as well as the ability to stimulate new bone formation. Such features could be beneficial for periodontal pathology therapy. Methods: A literature review was conducted using filtered electronic databases (Cochrane and Trip) and unfiltered databases (Medline/PubMed, Scielo and Google Scholar). The articles chosen were controlled and randomized clinical trials that performed local delivery of statins to humans and assessed the effects of immunomodulation and bone regeneration on periodontal disease between 2010 and 2017. All of the studies were blind or double-blind and were written in English. Results: The inclusion criteria were applied to a total of 79 identified articles, and 10 studies were ultimately chosen. The results show that an injected dose of statins or the local delivery of atorvastatin (ATV) leads to a significant improvement in clinical and radiographic periodontal parameters. Moreover, rosuvastatin (RSV) induced stronger beneficial effects when administered systemically, whereas ATV and simvastatin (SMV) had better results following topical delivery. Conclusions: Statins can affect periodontal status, increasing the gain in clinical attachment and decreasing gingival bleeding, probing depth and the magnitude of bone defects. For this reason, statins represent an excellent support measure for conventional periodontal therapy. Specifically, positive effects are seen for local delivery of statins as an adjunct treatment to scaling and root planing (SRP) at doses of 1.2 to 2%. Statins could be administered through topical delivery via direct injection in the periodontal pocket or by brushing with medicated dentifrices. More studies with appropriate designs should evaluate the short and long term clinical benefit of statins inpatients with periodontal pathology. These studies should determine the appropriate dose, timing side effects and ideal vehicles for delivery.

Atorvastatin-medicated dentifrice significantly inhibits CD4+ T cell proliferation: in vitro pilot study / Pasta dental medicada con atorvastatina inhibe de forma significativa la proliferación de células T CD4+: un estudio piloto in vitro

Reports indicate that statins (cholesterol-lowering drugs), in addition to lowering cholesterol, have an immunomodulatory effect. This effect may be beneficial for the treatment of several diseases, including periodontal disease. The aim of the present study was to evaluate the immunomodulatory effect of an atorvastatin-medicated dentifrice on CD4+ T cell proliferation. CD4+ T cell proliferation assays and peripheral blood mononuclear cell (PBMC) viability assays were conducted on PBMCs from healthy donors cultured under the following conditions: control, atorvastatin solution, atorvastatin-medicated dentifrice, and dentifrice without atorvastatin at concentrations of 1, 5, 10, 50 and 100 µM. A Generalized Equation Estimation (GEE) model was used to analyze concentration versus proliferation and concentration versus percentage of dead cells within each group evaluated. Atorvastatin-medicated dentifrice (p-value <0.0001) and atorvastatin solution (p-value <0.0001) significantly inhibited CD4+ T cell proliferation in a dose-dependent manner compared with the dentifrice without atorvastatin and control conditions. Only the relationship between atorvastatin solution and percentage of dead cells was significant compared to the other conditions (p-value 0.019). The results revealed that atorvastatin-medicated dentifrice at concentrations of 1 to 100 µM had immunomodulatory effects, inhibiting CD4+ T cell proliferation without affecting PBMC viability. The other components of the dentifrice did not affect CD4+ T cell proliferation or cell viability, indicating its utility as a vehicle to achieve the desired effects of atorvastatin in periodontal tissue. Controlled clinical trials are still needed to evaluate the clinical effects of an atorvastatin-medicated dentifrice on the periodontium.

La literatura indica que las estatinas (medicamentos para bajar el colesterol), además de reducir el colesterol, tienen un efecto inmunomodulador. Este efecto puede ser beneficioso para el tratamiento de varias enfermedades, incluyendo la enfermedad periodontal. El objetivo de este estudio es evaluar el efecto inmunomodulador de una pasta dental medicada con atorvastatina sobre la proliferación celular de linfocitos T CD4+. A partir de células mononucleares de sangre periférica de donantes sanos (PBMC), se realizaron ensayos de proliferación y viabilidad de linfocitos T CD4+ bajo las siguientes condiciones: control, solución de atorvastatina, dentífrico medicado con atorvastatina y dentífrico sin atorvastatina, en concentraciones 1, 5, 10, 50 and 100 µM. Se realizó el análisis estadístico utilizando el modelo Generalized Equation Estimation (GEE) a fin de analizar la concentración versus la proliferación y la concentración versus el porcentaje de muerte celular para cada uno de los grupos. El dentífrico medicado con atorvastatina (valor p <0,0001) y solución de atorvastatina (valor p <0,0001) inhibieron significativamente la proliferación de células T CD4 + de una manera dependiente de la dosis en comparación con el dentífrico sin atorvastatina y condiciones de control. Sólo la relación entre la atorvastatina solución y el porcentaje de células muertas fue significativa en comparación con las otras condiciones (vale-p 0,019). Los resultados revelaron que el dentífrico medicado con atorvastatina en concentraciones de 1 a 100 mM tenía efectos inmunomoduladores, inhibiendo la proliferación de células T CD4 + sin afectar la viabilidad de PBMC. Los otros componentes del dentífrico no afectaron la proliferación de células T CD4 + o la viabilidad celular, indicando su utilidad como vehículo para conseguir los efectos deseados de atorvastatina en el tejido periodontal. Todavía se necesitan ensayos clínicos controlados para evaluar los efectos clínicos de un dentífrico medicado con atorvastatina sobre el periodonto.