3D virtual patient-Magnetically retained printed stackable system for implant guided placement: Case report.

OBJECTIVE: The aim of this report is to present the complete workflow of 3D virtual patient for planning and performing implant surgery with magnetically retained 3D-printed stackable guides. CLINICAL CONSIDERATIONS: A 3D-printed stackable system was proposed based on bone, dental, and facial references. Initially, a 66-year-old male patient was digitalized through photographs, cone beam computed tomography, and intraoral scans (Virtuo Vivo, Straumann). All files were merged to create a 3D virtual patient in the planning software (coDiagnostiX, Straumann). Sequential stackable guides were designed, printed, and cured. Magnets were inserted into connectors, and the interim protheses received color characterization. Four mounted guides were produced for the specific purposes of pin fixation, bone reduction, implant placement, and immediate provisionalization. After surgery and healing period, patient digital data were updated. Final implant positions were compared to planned values and inconsistencies were clinically acceptable. The mean angular deviation was 5.4° (3.2-7.3) and mean 3D discrepancies were of 0.90 mm (0.46-1.12) at the entry point and 1.68 mm (1.00-2.20) at implant apex. Case follow-up revealed stability, patient's comfort, and no intercurrences. CONCLUSION: Magnetically retained stackable guides provide treatment accuracy and reduce surgical and prosthetic complications. The projected virtual patient enhances decision-making and communication between the multidisciplinary team and the patient, while decreases time and costs. CLINICAL SIGNIFICANCE: Bidimensional diagnosis and freehand implant placement have limitations and outcomes often rely on professionals' expertise. Performing facially driven virtual planning improves treatment predictability. This approach promotes function, esthetic harmony, and patient satisfaction. Implant guided surgery and 3D printed prostheses constitute a reproducible digital workflow that can be implemented into clinical practice to optimize dental care.

Effect of mutanase and dextranase on biofilms of cariogenic bacteria: A systematic review of in vitro studies.

Matrix-degrading enzymes are promising non-biocidal adjuncts to dental biofilm control and caries prevention. By disrupting the biofilm matrix structure, enzymes may prevent biofilm formation or disperse established biofilms without compromising the microbial homeostasis in the mouth. This study reviewed whether treatment with mutanase and/or dextranase inhibits cariogenic biofilm growth and/or removes cariogenic biofilms in vitro. An electronic search was conducted in PubMed, EMBASE, Scopus, Web of Science, Cochrane, and LIVIVO databases. Manual searches were performed to identify additional records. Studies that quantitatively measured the effect of mutanase and/or dextranase on the inhibition/removal of in vitro cariogenic biofilms were considered eligible for inclusion. Out of 809 screened records, 34 articles investigating the effect of dextranase (n = 23), mutanase (n = 10), and/or combined enzyme treatment (n = 7) were included in the review. The overall risk of bias of the included studies was moderate. Most investigations used simple biofilm models based on one or few bacterial species and employed treatment times ≥30 min. The current evidence suggests that mutanase and dextranase, applied as single or combined treatment, are able to both inhibit and remove in vitro cariogenic biofilms. The pooled data indicate that enzymes are more effective for biofilm inhibition than removal, and an overall higher effect of mutanase compared to dextranase was observed.

Magnetic resonance imaging for jawbone assessment: a systematic review.

PURPOSE: To evaluate the accuracy of magnetic resonance imaging (MRI) for jawbone assessment compared to reference-standard measurements in the literature. MATERIALS AND METHODS: An electronic database search was conducted in PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library in June 2022, and updated in August 2023. Studies evaluating the accuracy of MRI for jawbone assessment compared with reference-standard measurements (histology, physical measurements, or computed tomography) were included. The outcome measures included bone histomorphometry and linear measurements. The risk of bias was assessed by the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2). The review was registered in the PROSPERO database (CRD42022342697). RESULTS: From 63 studies selected for full-text analysis, nine manuscripts were considered eligible for this review. The studies included assessments of 54 participants, 35 cadavers, and one phantom. A linear measurement error ranging from 0.03 to 3.11 mm was shown. The accuracy of bone histomorphometry varies among studies. Limitations of the evidence included heterogeneity of MRI protocols and the methodology of the included studies. CONCLUSION: Few studies have suggested the feasibility of MRI for jawbone assessment, as MRI provides comparable results to those of standard reference tests. However, further advancements and optimizations are needed to increase the applicability, validate the efficacy, and establish clinical utility of these methods.

Is the digital workflow more efficient for manufacturing partial-coverage restorations? A systematic review.

STATEMENT OF PROBLEM: A consensus on whether a fully digital workflow can replace conventional methods of manufacturing partial-coverage restorations is lacking. PURPOSE: The purpose of this systematic review was to evaluate the accuracy, fit, and clinical outcomes of inlay, onlay, overlay, and endocrown restorations obtained with both digital and conventional workflows. MATERIAL AND METHODS: This study complied with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered in the International Prospective Register of Systematic Reviews database (CRD42021258696). Studies evaluating the accuracy, fit, and clinical outcomes of inlay, onlay, overlay, and endocrown restorations obtained with digital and conventional workflows were included from 5 databases searched in November 2022. The Checklist for Reporting Randomized Clinical Studies (ROB 2) and the Checklist for Reporting In vitro Studies (CRIS guidelines) were used to assess the risk of bias. RESULTS: Twenty-three studies were included in this review. Sixteen studies evaluated marginal and internal fit, 5 evaluated accuracy, 3 evaluated fracture resistance, and 1 evaluated long-term clinical performance. Although most studies reported acceptable clinical outcomes for both workflows, 11 studies showed better results with the conventional workflow, 10 with the digital workflow, and 2 reported that the outcomes of the workflows were similar. CONCLUSIONS: Clinically acceptable values have been reported for the parameters evaluated in both digital and conventional workflows, and no consensus has been reached regarding the more efficient method.

SEMAC + VAT for Suppression of Artifacts Induced by Dental-Implant-Supported Restorations in Magnetic Resonance Imaging.

The purpose of this study was to assess the feasibility of SEMAC + VAT to reduce artifacts induced by dental implant-supported restorations, such as its impact on the image quality. Dental-implant supported restorations were installed in a dry mandible. Magnetic resonance scans were acquired on a 3-Tesla MRI system. Artifact suppression (SEMAC + VAT) was applied with different intensity modes (weak, moderate, strong). Artifacts assessment was performed by measuring the mandible volume increase in MRI images prior (reference dataset) and after installation of dental implant-supported prosthesis. Image quality was assessed by two examiners using a five-point scale. Inter-examiner concordance and correlation analysis was performed with Cronbach's alpha and Spearman's test with a significance level at p = 0.05. Mandible volume increased by 60.23% when no artifact suppression method was used. By applying SEMAC + VAT, the volume increase ranged from 17.13% (strong mode) to 32.77% (weak mode). Visualization of mandibular bone was positively correlated with SEMAC intensity degree. SEMAC + VAT reduced MRI artifacts caused by dental-implant supported restorations. A stronger suppression mode improved visualization of mandibular bone in detriment of the scanning time.

The crown lengthening double guide and the digital Perio analysis.

OBJECTIVE: This article describes a surgical crown lengthening double guide, which was digitally obtained to improve diagnosis, treatment outcome, and follow-up. CLINICAL CONSIDERATIONS: The rehabilitation of anterior dental esthetics should involve interdisciplinary and facially driven planning for achieving pleasant long-term outcomes. Surgical crown lengthening is one of the most common periodontal surgery, which can be assisted by digital tools to improve surgical planning and follow-up. CONCLUSION: The double guide for surgical crown lengthening allows the proper management of hard and soft tissues for achieving a predefined goal based on biological requirements and facially driven planning. In addition, the digital quality control allows the follow-up compared with the pre-operative condition and planned treatment plan. CLINICAL SIGNIFICANCE: The use of digital tools allow the clinician to develop a facially driven planning with proper communication with the team and patient, leading to a shorter, more predictable, and less invasive surgical technique, reducing postoperative inflammation and increasing patient comfort.

Clinical and In Situ Oral Biofilm Formation on Dental Implant Abutment Materials: A Systematic Review.

PURPOSE: This review aimed to summarize the current literature on the oral biofilm formation on alternative abutment materials compared with titanium (Ti) or Ti alloy in clinical and in situ conditions. MATERIALS AND METHODS: An electronic database search was conducted in PubMed, Cochrane Library, EMBASE, Scopus, Web of Science, LIVIVO, BVS, ProQuest, and OpenGrey up to November 2020. Clinical and in situ studies evaluating the biofilm formed on metallic, ceramic, or polymeric abutment materials compared with Ti or Ti alloy were included. Outcome measures were microbial counts/profile, cell viability, and biofilm coverage/thickness. Clinical parameters were deemed secondary outcomes. Risk of bias was assessed by RoB 2 and ROBINS-I tools. RESULTS: A total of 10 clinical and 9 in situ studies were included. Meta-analysis was not performed due to heterogeneity across studies. The abutment materials polytetrafluoroethylene, gold alloy, gold-platinum alloy, cobalt-chromium, alumina, and zirconia were reported. Six out of ten clinical studies (60%) and four out of nine in situ studies (44%) found no qualitative or quantitative microbiologic differences between tested materials. When significant differences were detected, conflicting results were reported. Clinical outcomes were consistent with healthy conditions for all investigated materials. CONCLUSION: There is not enough evidence to support the existence of relevant microbiologic differences in the biofilm formed on alternative abutment materials over Ti and its alloys in oral conditions. No evident relationship between microbiologic results and clinical outcomes were found. In situ studies and polymicrobial analyses showed a higher tendency to find significant differences between materials.

Digital versus conventional workflow for the fabrication of physical casts for fixed prosthodontics: A systematic review of accuracy.

STATEMENT OF PROBLEM: A consensus on the accuracy of additively manufactured casts in comparison with those fabricated by using conventional techniques for fixed dental prostheses is lacking. PURPOSE: The purpose of this systematic review was to determine the accuracy of additively manufactured casts for tooth- or implant-supported fixed dental prostheses in comparison with that of gypsum casts. MATERIAL AND METHODS: This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered with the International Prospective Register of Systematic Reviews (PROSPERO) database (CDR42020161006). Eight databases were searched in December 2019 and updated in September 2020. Studies evaluating the dimensional accuracy of additively manufactured casts for fixed dental prostheses in comparison with that of gypsum casts were included. An adapted checklist for reporting in vitro studies (Checklist for Reporting In vitro Studies guidelines) was used to assess the risk of bias. RESULTS: Eight studies evaluating tooth-supported fixed dental prosthesis casts and 7 studies evaluating implant-supported fixed dental prosthesis casts were eligible for this review. Gypsum casts showed greater accuracy (trueness and precision) in most studies, although additively manufactured casts also yielded highly precise data. One study was associated with a low risk of bias, 9 with a moderate risk of bias, and 5 with a high risk of bias. CONCLUSIONS: In vitro studies showed that additively manufactured casts and gypsum casts share similar accuracy within the acceptable range for the fabrication of casts. The quality of scanned data, additive manufacture technology, printing settings, and postprocessing procedures plays an essential role in the accuracy of additively manufactured casts. Clinical studies are required to confirm these findings.

Three-Dimensional (3D) Facially Driven Workflow for Anterior Ridge Defect Evaluation: A Treatment Concept.

The esthetic rehabilitation of anterior ridge defects and achieving patient satisfaction have become major clinical challenges for dentists and technicians. Poor diagnosis and treatment planning are frequently associated with multiple surgical procedures that fail to meet patient expectations. The loss of hard and soft tissues in anterior ridges results in an esthetically compromised zone that affects the rehabilitation prognosis. The presence of interdental papilla and papillary configuration play a decisive role in patient satisfaction. A treatment plan considering esthetic parameters, prosthetic needs, and morphological defects must be used to improve treatment outcomes. Therefore, this study aims to propose a treatment concept for anterior ridge defects that focuses on digital evaluation systems and is guided by an ideal facially driven smile design project. In addition, the relevance of the papilla for esthetic outcomes and treatment alternatives for anterior ridge defects are also addressed.

Narrow-diameter implants in the anterior region: A meta-analysis.

PURPOSE: Implants in the anterior region are challenging, and literature reporting outcomes of narrow-diameter implants (NDIs) in anterior sites is scarce. This systematic review summarized evidence of functional and esthetic performance of anterior single crowns supported by NDIs. MATERIALS AND METHODS: Ten databases were searched to find studies evaluating anterior single crowns supported by NDIs. Risk of bias was assessed, and random-effects meta-analyses were applied to analyze mean differences in survival, success, and marginal bone level (MBL). The review was registered in the PROSPERO database (CRD42018089886). RESULTS: Twenty-one studies meeting the screening criteria were included for qualitative analysis, and three for meta-analysis. A total of 892 NDIs, placed in 736 patients, were analyzed. Follow-up duration varied from 12 months to 14 years (mean: 40 months), and 16 failures (implant loss) were recorded. Fixed-effect meta-analysis (I2 = 0%) of survival rate revealed a risk difference of 0.02 (95% CI: -0.03 to 0.08), between NDIs and controls (regular-diameter implants), without differences between groups (P = .39). Success rates ranged from 84.2% to 100% (mean: 95.2%). Random-effects meta-analysis (I2 = 56%) of MBL indicated a mean difference of 0.02 mm (95% CI: -0.21 to 0.25), without differences between groups (P = .87). CONCLUSION: Single crowns supported by NDIs are a predictable treatment, since their survival rate and MBL are comparable to those supported by regular-diameter implants. Due to data shortage reporting esthetic outcomes, more studies are needed to evaluate the long-term performance of the single crowns supported by NDIs in the anterior region.

Evaluation of cell proliferation in cystic lesions associated with impacted third molars.

The purpose of this study was to evaluate the metabolism and epithelial cell proliferation of odontogenic keratocyst (OKC), dentigerous cyst (DC), and unicystic ameloblastoma (UA) by quantifying the nucleolar organizing regions (AgNORs) and Ki-67 protein immunoexpression. Forty-eight cases (16 OKC, 16 DC, and 16 UA) were evaluated retrospectively. The metabolism and epithelial cell proliferation was measured by the Ki-67 positive cell percentage index and by the mean AgNOR count in each group. The Ki-67 and AgNOR counts were significantly higher in OKC comparing to the DC and UA (p < .001). Ki-67 positive cells were observed higher in suprabasal cell layers of OKC with uniform distribution, a few of them were predominantly observed in basal cell layer in DC and UA. The AgNOR count was significantly higher in the OKC basal cell layers and observed throughout the lining epithelium of DC and UA. Ki-67 and AgNOR reinforced the aggressive character of OKC, presenting high metabolism and cellular proliferation compared to DC and UA, possibly due to its more aggressive clinical behavior and high recurrence rate. RESEARCH HIGHLIGHTS: We evidence higher metabolism and epithelial cell proliferation in OKC when compared to UA and DC, supporting its aggressive aspect and its high rate of recurrence. OKC had intense and predominant labeling of Ki-67 on the suprabasal layer unlike UA and DC.