A double-blind randomized within-subject study to evaluate clinical applicability of four digital workflows for the fabrication of posterior single implant crown.

OBJECTIVE: To compare efficiency and clinical efficacy of posterior single implant crowns (PSIC) fabricated using four digital workflows. MATERIALS AND METHODS: Twenty-two patients with one missing first molar were included. Each patient received four screw-retained implant crowns fabricated through four different workflows including a fully digital workflow with immediate digital impression (Group i-IOS), a fully digital workflow with digital impression after implant osseointegration (Group d-IOS), a model-based hybrid workflow using immediate analogue impression (Group i-AI), and a model-based hybrid workflow with conventional analogue impression after implant osseointegration (Group d-AI). The crown delivery sequence was randomized and blinded. The efficiency for each workflow and clinical outcome of each crown were recorded. RESULTS: The average clinical working time in fully digital workflows (i-IOS 46.90 min, d-IOS 45.66 min) was significantly lower than that in the hybrid workflows (i-AI 54.59 min, d-AI 55.96 min; p < .001). Significantly more laboratory time was spent in hybrid workflows (i-AI 839.60 min, d-AI 811.73 min) as compared to fully digital workflows (i-IOS 606.25 min, d-IOS 607.83 min, p < .01). No significant differences in the chairside time at delivery were found. More crowns in Group i-AI (15%) needed additional laboratory interventions than in the other groups (p = .029). CONCLUSION: Digital impression and model-free fully digital workflow improved prosthetic efficiency in the fabrication of PSIC. With the limitation that the results were only applicable to the implant system used and the digital technologies applied, findings suggested that workflows integrating immediate impression with implant surgery procedure was clinically applicable for restoration of PSIC.

The accuracy of dynamic computer assisted implant surgery in fully edentulous jaws: A retrospective case series.

OBJECTIVES: To evaluate the accuracy of implant placement using a dynamic navigation system in fully edentulous jaws and to analyze the influence of implant distribution on implant position accuracy. MATERIALS AND METHODS: Edentulous patients who received implant placement using a dynamic navigation system were included. Four to six mini screws were placed in the edentulous jaw under local anesthesia as fiducial markers. Then patients received CBCT scans. Virtual implant positions were designed in the planning software based on CBCT data. Under local anesthesia, implants were inserted under the guidance of the dynamic navigation system. CBCTs were taken following implant placement. The deviation between the actual and planned implant positions was measured by comparing the pre- and postsurgery CBCT. RESULTS: A total of 13 edentulous patients with 13 edentulous maxillae and 7 edentulous mandibles were included, and 108 implants were placed. The average linear deviations at the implant entry point and apex were 1.08 ± 0.52 mm and 1.15 ± 0.60 mm, respectively. The average angular deviation was 2.85 ± 1.20°. No significant difference was detected in linear and angular deviations between the maxillary and mandibular implants, neither between the anterior and posterior implants. CONCLUSIONS: The dynamic navigation system provides high accuracy for implant placement in fully edentulous jaws, while the distribution of the implants showed little impact on implant position accuracy.

Evaluation of Oral Health-Related Quality of Life and Patient Satisfaction in Three-Implant-Retained Mandibular Overdentures: A Randomized Crossover Clinical Trial.

PURPOSE: To assess oral health-related quality of life (OHRQoL) and patient satisfaction with a three-implant-retained mandibular overdenture. MATERIALS AND METHODS: In this randomized crossover clinical trial, 20 edentulous patients received a new set of conventional complete dentures (CDs; baseline). Subsequently, three implants were placed in the anterior mandible: two were placed in the canine regions bilaterally and one in the midline. After successful osseointegration, CDs were attached to the implants using resilient attachments. The overdenture was retained either by three implants (test group) or two implants (control group). The sequence of treatment was randomized such that each patient experienced both treatment options for 6 months each. OHRQoL was assessed at baseline and after 6 months of function for each treatment option using the Oral Health Impact Profile (OHIP-14) and visual analog scale (VAS) scores. Statistical analyses were performed using Friedman and Wilcoxon signed rank tests. RESULTS: CD resulted in significantly higher OHIP-14 and VAS scores (25.25 + 6.42, 8.55 + 1.73) compared to both the control group (11.15 + 5.39, 4 + 2; P < .001) and the test group (6.25 + 4.02, 2.06 + 1.48; P < .001). Similarly, significantly higher mean OHIP-14 and VAS scores were noted for the control group compared to the test group (P < .001). CONCLUSIONS: Overdentures retained by three implants resulted in better OHRQoL scores and higher patient satisfaction compared to overdentures retained by two implants and CDs. Int J Prosthodont 2023;36:554-56.

The Capacity to Change the Lightness of Discolored Tooth Substrates by Means of Minimally Invasive Restorations: Perception by Dentists, Dental Technicians, and Laypersons

PURPOSE: To evaluate the minimal ceramic thickness needed to increase the lightness by one value by means of glass-ceramic restorations perceived by dental technicians, dentists, and laypersons. MATERIAL AND METHODS: A total of 15 assessment pairs (reference and test samples) were formed using glass-ceramic blocks in four different colors. Each assessment pair was comprised of two underground blocks differing in one value of lightness. On top of the underground blocks, glass-ceramic platelets were cemented in five different thicknesses (0.1 to 0.5 mm) and in the same color as the reference. Dental technicians, dentists, and laypersons (n = 41/group) were asked to determine the presence of a color difference between the two samples under standardized lighting conditions. The threshold ceramic thickness was defined as the thickness at which ≥ 50% of the evaluators were not able to perceive a difference within an assessment pair. The thresholds were analyzed, and groups were compared by applying chi-square test (P < .05). RESULTS: The majority of dentists and dental technicians (> 50%) detected a lightness difference between the test and reference samples up to a ceramic thickness of 0.5 mm. The majority of laypersons (≥ 50%) did not perceive a lightness difference with ceramic thickness of 0.5 mm. If separated by the different color changes, the threshold ceramic thickness started at 0.4 mm and varied within the groups of evaluators and by the lightness of the assessed color. CONCLUSION: A considerable number of evaluators perceived a lightness difference when minimally invasive ceramic restorations of 0.5-mm thickness were applied. The threshold ceramic thickness, however, was reduced when the lightness of the substrate was lower.

Pontic site development for fixed dental prostheses with and without soft tissue grafting: 1-year results of a cohort study.

AIM: To describe and compare the pontic site development for fixed-dental prostheses (FDPs) with and without soft tissue grafting up to one-year post insertion of FDPs. MATERIALS AND METHODS: A convenience sample of 24 patients participating in an ongoing RCT was provided with three-unit tooth-borne FDPs. Six patients received a subepithelial connective tissue graft (SCTG) at the pontic site, whereas 18 patients were treated without any soft tissue graft (CONTROL). Digital impressions were taken prior to tooth preparation, after tooth preparation, after insertion of the final FDP, and at the 1 year of follow-up. The obtained stereolithography files (STL) were superimposed and profilometric as well as linear changes of the soft tissue profile were assessed at the pontic regions. Profilometric outcomes included changes of the ridge contour, the alveolar ridge width, and the crown height of the pontic. Further outcomes assessed included: the papilla index, the pink esthetic score (PES), probing depth (PD), bleeding on probing (BOP), and plaque control record (PCR). Descriptive and nonparametric statistics were applied for all outcome measures. RESULTS: The median profilometric contour between tooth preparation and 1 year after the insertion of the final FDP decreased by - 0.25 mm [Q1, Q3: - 0.36, 0.14] in the CONTROL group and increased by 0.61 mm [Q1, Q3: - 0.18, 1.06] in the SCTG group (intergroup p = 0.038). The alveolar ridge width between prior to tooth preparation and the one-year follow-up amounted to - 0.12 mm [Q1, Q3: - 0.74, 0.70] (= loss) in the CONTROL group and to 2.23 mm [Q1, Q3: 0.62, 3.86] (= gain) in the SCTG group (intergroup p = 0.032). At one year, the median crown height of the pontic tended to decrease by - 1.24 mm [Q1, Q3: - 2.05, - 1.05] in the SCTG group (intragroup p = 0.094) and by - 0.22 mm [Q1, Q3: - 0.58, 0.66] in the CONTROL group (intragroup p = 0.831), with significant differences between the groups (intergroup p = 0.022). The papilla index between prior to tooth preparation and one year of follow-up improved significantly in both groups (p < 0.05). Between FDP delivery and one year of follow-up, the PES values decreased significantly in the CONTROL group (intragroup p = 0.007), while in the SCTG group the change was not significant (intragroup p = 0.875). Clinical parameters (PD, BOP, and PCR) remained stable over time and did not differ between the groups at any time point (intergroup p > 0.05). CONCLUSION: Within the limitations of the present study, soft tissue grafting tends to limit contour changes at pontic sites, thus maintaining the esthetic outcomes over time. The lack of soft tissue grafting results in stable clinical outcomes; however, it may lead to a decrease in aesthetic outcomes over time. CLINICAL RELEVANCE: Autogenous soft tissue grafting seems to be a valid therapeutic option for the development of the pontic site to restore ridge defects prior to the delivery of fixed dental prostheses and to limit dimensional changes over time.

Mechanical stability of fully personalized, abutment-free zirconia implant crowns on a novel implant-crown interface.

OBJECTIVES: To test the failure load and failure mode of a novel implant-crown interface specifically designed for the fabrication of fully personalized, abutment-free monolithic zirconia CAD-CAM crowns compared to conventional implant-abutment interfaces involving prefabricated or centrally manufactured abutments for zirconia CAD-CAM crowns. METHODS: Implants (N=48) were divided into groups (n=12) according to different implant-abutment interface designs: (1) internal implant connection with personalized, abutment-free CAD-CAM crowns (Abut-Free-Zr), (2) internal conical connection with customized, centrally manufactured zirconia CAD-CAM abutments (Cen-Abut-Zr), (3) prefabricated titanium base abutments from manufacturer 1 (Ti-Base-1), (4) additional prefabricated titanium base abutments from manufacturer 2 (Ti-Base-2). All specimens were restored with a screw-retained monolithic zirconia CAD-CAM molar crown and subjected to thermomechanical aging (1.200.000 cycles, 49 N, 1.67 Hz, 30° angulation, thermocycling 5-50°C). Static load until failure was applied in a universal testing machine. Failure modes were analyzed descriptively under digital microscope. Mean failure load values were statistically analyzed at a significance level of p<0.05. RESULTS: All specimens survived thermomechanical aging. The mean failure loads varied between 1332 N (Abut-Free-Zr) and 1601 N (Ti-Base-2), difference being significant between these groups (p<0.05). No differences between the other groups were seen. The predominant failure mode per group was crown fracture above implant connection (Abut-Free-Zr, 75%), abutment fracture below implant neck (Cen-Abut-Zr, 83%), crown fracture leaving an intact abutment (Ti-Base-1/Ti-Base-2 100%). CONCLUSIONS: Implant-crown interface with fully personalized, abutment-free monolithic CAD-CAM zirconia crowns exhibited similar failure loads as conventional implant-abutment interfaces (except group Ti-Base-2) involving CAD-CAM crowns with prefabricated or centrally manufactured abutment. CLINICAL SIGNIFICANCE: The new implant connection simplifies the digital workflow for all-ceramic implant reconstructions. The specific design of the implant-crown interface allows the fabrication of fully personalized, abutment-free zirconia implant crowns both in-house and in-laboratory without the need of a prefabricated abutment or central manufacturing.

An in vitro comparison of the marginal and internal adaptation of ultrathin occlusal veneers made of 3D-printed zirconia, milled zirconia, and heat-pressed lithium disilicate.

STATEMENT OF PROBLEM: Whether additively produced zirconia could overcome problems with conventional computer-aided design and computer-aided manufacture (CAD-CAM) such as milling inaccuracies and provide accurate occlusal veneers is unclear. PURPOSE: The purpose of this in vitro study was to compare the marginal and internal fit of 3D-printed zirconia occlusal veneers with CAD-CAM-fabricated zirconia or heat-pressed lithium disilicate ceramic (LS2) restorations on molars. MATERIAL AND METHODS: The occlusal enamel in 60 extracted human molars was removed, with the preparation extending into dentin. Occlusal veneers at a thickness of 0.5 mm were designed and manufactured according to their group allocation: 3DP, 3D-printed zirconia; CAM, milled zirconia; and HPR, heat-pressed LS2. The prepared teeth and restorations were scanned and superimposed, and the marginal and internal adaptation were measured 2- and 3-dimensionally; the production accuracy (trueness) was also measured. The comparisons of the group medians were performed with nonparametric methods and a pairwise group comparison (α=.05). RESULTS: Three-dimensionally printed zirconia revealed median outcomes of 95 µm (margin), 252 µm (cusp), 305 µm (fossa), and 184 µm (3D internal adaptation). CAM showed median values of 65 µm (margin), 128 µm (cusp), 203 µm (fossa), and 120 µm (3D internal adaptation). The respective values for the group HPR were 118 µm (margin), 251 µm (cusp), 409 µm (fossa), and 180 µm (3D internal adaptation). Significant differences (P<.001) between CAM and 3DP (cusp, fossa, 3D internal adaptation) and between CAM and HPR (all regions) were found, with the former group showing higher accuracies. The trueness showed median discrepancies of 26 µm (3DP), 13 µm (CAM), and 29 µm (HPR) with significant differences (P<.001) for the comparisons 3DP-CAM and CAM-HPR. CONCLUSIONS: Three-dimensionally printed zirconia occlusal veneers produced by means of lithography-based ceramic manufacturing exhibit a marginal adaptation (95 µm) and a production accuracy (26 µm) similar to those of conventional methods.

Effect of tooth brush abrasion on the color, gloss and surface roughness of internally and externally stained monolithic ceramic materials.

PURPOSE: To measure the durability of the color, change in surface roughness and gloss of stained monolithic ceramic materials subjected to artificial tooth brush abrasion. MATERIALS AND METHODS: Standardized specimens were manufactured from pressable lithium-disilicate glass ceramic (PC; IPS e.max Press), machinable lithium-disilicate glass ceramic (MC; IPS e.max CAD), and zirconia (ZR; Zenostar). Ceramic staining was applied before (internal; in) and after crystallization/sintering (external; ex). Of each ceramic material, specimens without staining were prepared (no staining; no). Porcelain-fused-to-metal specimens served as control (PFM). Each group consisted of 15 specimens. Tooth brushing was simulated with tooth brushing strokes of 21.6 k, 43.2 k, and 64.8 k. Color, gloss and roughness were measured at baseline and after cycle intervals. Kruskal-Wallis and paired Post-hoc Conover tests were applied to detect statistical differences between treatment groups. Differences before and after aging were calculated by Wilcoxon signed rank test (α=0.05). RESULTS: In all groups, color difference (∆E) was statistically significant after aging: no-PC (P<.001, 95% CI[0.14,0.84]), no-MC (P=.003, 95% CI[0.23,1.12]), no-ZR (P=.003, 95% CI[0.33,0.62]), in-MC (P=.003, 95% CI[0.35,0.73]), in-ZR (P=.003, 95% CI[0.09,0.32]), ex-PC (P=.003, 95% CI[0.54,0.98]), ex-MC (P<.001, 95% CI[0.23,1.26]), ex-ZR (P=.003, 95% CI[0.27,0.55]), and PFM (P=.002, 95% CI[0.22,0.34]). Aging increased surface roughness and decreased the gloss within all subgroups showing statistical significance. CONCLUSION: Color, gloss and roughness of stained monolithic ceramic materials changed significantly by means of tooth brush abrasion in vitro. Color changes were below the threshold value for the detection by the human eye (∆E 1.8).

Production time, effectiveness and costs of additive and subtractive computer-aided manufacturing (CAM) of implant prostheses: A systematic review.

OBJECTIVE: To systematically review the dental literature for clinical studies reporting on production time, effectiveness and/or costs of additive and subtractive computer-aided manufacturing (CAM) of implant prostheses. MATERIALS AND METHODS: A systematic electronic search for clinical studies from 1990 until June 2020 was performed using the online databases Medline, Embase and Cochrane. Time required for the computer-aided design (CAD) process, the CAM process, and the delivery of the CAD-CAM prostheses were extracted. In addition, articles reporting on the effectiveness and the costs of both manufacturing technologies were included. RESULTS: Nine clinical studies were included reporting on subtractive CAM (s-CAM; 8 studies) and additive CAM (a-CAM; 1 study). Eight studies reported on the s-CAM of prosthetic and auxiliary components for single implant crowns. One study applied a-CAM for the fabrication of an implant bar prototype. Time was provided for the CAD process of implant models (range 4.9-11.8 min), abutments (range 19.7-32.7 min) and crowns (range 11.1-37.6 min). The time for s-CAM of single implant crown components (abutment/crown) ranged between 8.2 and 25 min. Post-processing (e.g. sintering) was a time-consuming process (up to 530 min). At delivery, monolithic/veneered CAD-CAM implant crowns resulted in additional adjustments chairside (51%/93%) or labside (11%/19%). CONCLUSIONS: No scientific evidence exists on production time, effectiveness and costs of digital workflows comparing s-CAM and a-CAM. For both technologies, post-processing may substantially contribute to the production time. Considering effectiveness, monolithic CAD-CAM implant crowns may be preferred compared to veneered CAD-CAM crowns.

Fabrication, workflow and delivery of reconstruction: Summary and consensus statements of group 4. The 6th EAO Consensus Conference 2021.

OBJECTIVES: To report assessments of four systematic reviews (SRs) on (i) clinical outcomes of all-ceramic implant-supported crowns (iSCs), (ii) production time, effectiveness, and costs of computer-assisted manufacturing (CAM), (iii) computer-assisted implant planning and surgery (CAIPS) time and costs, and (iv) patient-reported outcome measures (PROMS). MATERIAL AND METHODS: An author group consisting of experienced clinicians and content experts discussed and evaluated the SRs and formulated consensus on the main findings, statements, clinical recommendations, and need for future research. RESULTS: All four SRs were conducted and reported according to PRISMA and detailed comprehensive search strategies in at least three bibliometric databases and hand searching. The search strategies were deemed reproducible. Variation was noted regarding language restrictions and inclusion of grey literature, but the search comprehensiveness appeared persuasive. The SRs included bias risk assessments of the primary studies, and their study methodology impacted the interpretations of the extracted data. CONCLUSIONS: (i) There is limited evidence (49 NRCT) showing that veneered and monolithic all-ceramic iSCs have excellent outcomes observed up to 3 years. (ii) There is no evidence evaluating production time and effectiveness comparing subtractive and additive CAM of implant models, abutments and crowns. (iii) There is limited evidence (4 RCT) that CAIPS involves more time and costs when considering the entire workflow and for diagnostics, manufacturing, and insertion of the restoration. Time seems to be the decisive factor for higher costs. (iv) Patients' comfort increases when optical compared to conventional impressions are used for fabricating iSCs and short-span FPDs (2 RCT, 5 NRCT).

Change in Color and Gloss Parameters of Stained Monolithic Resin-Ceramic CAD/CAM Materials After Simulated Aging: An In Vitro Study.

PURPOSE: To measure the effect of simulated aging on stained resin-ceramic CAD/CAM materials regarding the durability of color and gloss. MATERIALS AND METHODS: Test specimens (n = 15 per material) were prepared out of CAD/CAM ingots from two resin nanoceramics (Lava Ultimate [LVU], Cerasmart [CER]) and a polymer-infiltrated ceramic (ENA, VITA Enamic) stained with the manufacturer's recommended staining kit using photopolymerization. Control specimens were made of feldspathic ceramic (VITA Mark II [VM2]) and stained by means of ceramic firing. Negative control specimens (n = 15) (no staining) were prepared for each group. Color and gloss measurements were performed before and after each aging cycle by means of mechanical abrasion with a toothbrush. Groups were compared using Kruskal-Wallis test and paired post hoc Conover test. Changes within a group were calculated using Wilcoxon signed-rank test (α = .05). RESULTS: The color difference (ΔE) was statistically significant for all stained CAD/CAM materials after simulated aging: CER (P < .001, 95% CI: 2.96 to 3.69), LVU (P = .004, 95% CI: 1.09 to 1.46), ENA (P = .004, 95% CI: 0.20 to 0.42), and VM2 (P < .001, 95% CI: 0.29 to 1.08). Aging resulted in a statistically significant increase in gloss in the LVU group (P < 0.001, 95% CI: 13.78 to 17.29), whereas in the ENA (P < .001, 95% CI: 7.83 to 12.72), CER (P < .001, 95% CI: 2.69 to 8.44), and VM2 (P = .014, 95% CI: 0.22 to 1.87) groups, a significant decrease in gloss was noted. CONCLUSION: Color and gloss of stained resin-ceramic CAD/CAM materials changed significantly after aging by means of toothbrush abrasion in vitro.

Effect of connective tissue grafting on buccal bone changes based on cone beam computed tomography scans in the esthetic zone of single immediate implants: A 1-year randomized controlled trial.

BACKGROUND: Connective tissue grafting has a beneficial effect on the peri-implant mucosa, but the effect of grafting the buccal mucosa on buccal bone thickness (BBT) has not been investigated, although BBT is proposed to be a key factor for the soft-tissue contour. The aim of this trial was to assess the outcome of a connective tissue graft (CTG) in the esthetic zone of single immediate implants on the change of BBT according to cone beam computed tomography (CBCT) scan analysis. METHODS: In a 1-year randomized controlled trial, 60 patients received an immediately placed implant and provisionalization, either combined with CTG (test group) or without CTG (control group). CBCTs were taken preoperatively (Tpre ) and 1 year after definitive restoration (T2 ). Any change in BBT was assessed at different implant levels. Additionally, the change in mid-buccal mucosal level (MBML) and approximal marginal bone level were assessed. RESULTS: Fifty-five patients were available for statistical analysis (test group, n = 28; control group, n = 27). At T2 , the average change in BBT was significantly larger in the test group (-0.84 ± 0.61 mm) than in the control group (-0.46 ± 0.54 mm, P = 0.02). A MBML gain of 0.07 ± 0.85 mm in the test and a MBML loss -0.52 ± 1.16 mm in the control group was observed at T2 . Average loss of marginal bone was 0.05 ± 0.33 mm and 0.01 ± 0.38 mm, respectively. CONCLUSIONS: The application of CTG in the esthetic zone of immediately placed and provisionalized implants is accompanied with more loss of BBT, but at the same time better maintains the mid-buccal mucosal level.

The migration of neighboring and antagonist teeth three months after implant placement in healed single tooth-missing sites.

OBJECTIVES: To quantify the neighboring and antagonist teeth migration of a single posterior tooth-missing site within 3 months using digital scanning and measuring techniques. MATERIALS AND METHODS: Intraoral scans (IOS) were made in 40 patients presenting a single posterior tooth-missing gap and receiving implant therapy. IOS were obtained at the day of and three months after implant surgery rendering a digital baseline model (BM) and a digital follow-up model (FM). Digital models were superimposed using the implant scan body as reference. Antagonist models were processed by the best fit alignment. Dimensional change between anatomical landmarks on neighboring teeth and that of featuring points on antagonistic teeth were measured using a three-dimensional analysis software. The Mann-Whitney U test was applied to compare the tooth-moving distance between the mesial and distal neighboring teeth. The Kruskal-Wallis one-way ANOVA was used to test the difference in dimensional change in tooth-missing site among age subgroups. RESULTS: The mean dimensional change in the tooth-missing site was -37.62 ± 106.36 µm (median: -28.33 µm, Q25 -72.65/Q75 38.97) mesial-distally and -67.91 ± 42.37 µm (median: -61.50 µm, Q25 -88.25/Q75 -36.75) occlusal-gingivally. Eighteen out of 40 mesial neighboring teeth and 24 out of 40 distal neighboring teeth showed migration towards the implants. When patients were grouped according to age, the mesial-distal reduction in the tooth-missing site was significantly larger in patients younger than 30 years compared with those older than 50 years (p < .05). CONCLUSIONS: The dimensions of posterior tooth-missing sites decreased over an observation period of 3 months.

Ultrasound and CBCT analysis of blood flow and dimensions of the lingual vascular canal: A case control study.

OBJECTIVE: To assess the correlation between the diameter of the mandibular lingual vascular canal (MLVC) as determined on CBCT examination to blood flow and arterial diameter as determined by ultrasound Doppler analysis (USG) in dentate and edentulous patients. METHODS: 20 subjects were equally distributed into two groups based on the status of their dentition. Group 1 included dentate subjects (DE) and Group 2 included edentulous subjects (ED).The subjects from both the groups underwent CBCT scan for the assesement of the diameter of the MLVC.Similarly, USG was done to assess the diameter of the sublingual artery anastomosis and blood flow in the anterior mandible. Data was analysed using Karl Pearson's Correlation coefficient test and Student's unpaired 't' test. RESULTS: Irrespective of the status of the dentition and age, a positive correlation was noted between the diameter of foramen on CBCT examination and the diameter of anastomosing artery as studied by the USG (r â€‹= â€‹0.290).Similarly, a positive correlation was observed between the diameter of foramen on CBCT and the volume of blood entering the mandible (r â€‹= â€‹0.447).A positive correlation (r â€‹= â€‹0.138) was observed between the diameter of the anastomosing artery and the volume of blood entering the mandible. CONCLUSION: The anterior mandible has a rich vascular supply independent of age and status of the dentition.The dimensions and location of MVLC could be assessed on a CBCT prior to implant placement so that the operating surgeon has an idea about the vascularity of the region. Further studies with higher sample size should be undertaken to confirm these findings.

[Prosthetic implants used as orthodontic anchor-age - Introducing a complete digital workflow for clinical use]. / Prothetische Implantate zur kieferorthopädischen Verankerung ­ Einführung eines komplett digitalen Behandlungsablaufs für den klinischen Einsatz.

The aim of this case report was to introduce the clinical use of a prosthetic soft tissue level implant and a completely digitized workflow for the production of an individualized suprastructure fixated on prosthetic implants for orthodontic anchorage rein­forcement. A prosthetic soft tissue level implant was placed in the palatal region for orthodontic anchorage reinforcement. Based on an intraoral optical scan taken after implant osseointegration, the orthodontic suprastructure was manufactured entirely by means of computer­aided design and manufacturing (CAD/CAM). The individualized suprastructure was subsequently loaded in direct manner. The prosthetic implant was then re­moved in a non­invasive manner, similar to palatal implants.The analysis included clinical and laboratory fabrication steps. The placement of prosthetic implant in the palatal region proved to be a painless, easy and fast procedure, and provided absolute anchorage during the entire intended orthodontic treatment. Its non­invasive removal did not cause any adverse patient reactions. The digitally constructed suprastructure did not require any chairside adaptation at delivery and was suc­cessfully used for the intended orthodontic treatment.The reported case presents the successful placement, loading and removal of a prosthetic soft tissue level implant for ortho­dontic anchorage use in the palatal region. The described digital and model­free workflow provides a feasible and streamlined treatment modality for the fabrication of individualized ortho­dontic suprastructures by means of CAD/CAM for the use as or­thodontic anchorage reinforcement. This proof of principle should be substantiated with further larger­scaled investigations.

Accuracy of remote diagnoses using intraoral scans captured in approximate true color: a pilot and validation study in teledentistry.

BACKGROUND: Intraoral scans (IOS) provide three-dimensional images with approximate true colors representing a possible tool in teledentistry for remote examination. The aim of the present cross-sectional validation study was, therefore, to evaluate the levels of agreement between remote diagnoses derived from IOS and diagnoses based on clinical examinations for assessing dental and periodontal conditions. METHODS: The test sample comprised 10 patients representing different clinical conditions. Following the acquisition of IOS (Trios, 3Shape), a full-mouth dental and periodontal examination was done and periapical radiographs were taken. Ten dentists were asked to perform dental and periodontal scorings for each of the ten patients on a tablet computer presenting the IOS. Scores included diagnosis of gingivitis/periodontitis, and evaluated presence as well as amount of plaque and calculus, and presence of teeth exhibiting gingival recession, furcation involvement, erosion, tooth wear, stain, and non-carious cervical lesion, as well as presence of decayed, filled, and crowned teeth and implants. In a second round of assessments, the periapical radiographs were provided and the dentists were able to change the scores. The time for the remote assessment was recorded. The agreement between remote and clinical scorings (reference) was then analyzed descriptively. RESULTS: The mean time for the tele assessment was 3.17 min and the additional consultation of the radiographs accounted for another 1.48 min. The sensitivity and specificity values were 0.61 and 0.39 for gingivitis and 0.67 and 0.33 for periodontitis, with no relevant changes when radiographs were provided for the diagnosis of periodontitis (0.72 and 0.28). The agreement for dichotomized dental and periodontal indices ranged between 78 and 95%. With the provision of radiographs, the remote examiners were able to detect existing filled teeth, crowned teeth, and implants, whereas the detection of decayed teeth (70%) was not improved. CONCLUSIONS: The remote examination using IOS was effective in detecting dental findings, whereas periodontal conditions could not be assessed with the same accuracy. Still, remote assessment of IOS would allow a time-efficient screening and triage of patients. Improvement of the image quality of IOS may further allow to increase the accuracy of remote assessments in dentistry. According to the Swiss Regulation this investigation is not a clinical trial and therefore no registration in a WHO-registry is needed.

Prosthetic outcomes and clinical performance of CAD-CAM monolithic zirconia versus porcelain-fused-to-metal implant crowns in the molar region: 1-year results of a RCT.

OBJECTIVE: To investigate the clinical performance of monolithic zirconia implant crowns as compared to porcelain-fused-to-metal (PFM) implant crowns. MATERIALS AND METHODS: Seventy-six healthy patients received reduced diameter implants in the molar region. Following random allocation, either a monolithic zirconia crown (Mono-ZrO2 ) or a (PFM) was inserted. Crown and implant survival rates, modified USPHS criteria, clinical measurements, and interproximal marginal bone level (MBL) were assessed at crown delivery (baseline, BL) and at the 1-year follow-up (1y-FU). Data were analyzed descriptively. Fisher's exact test and Wilcoxon rank sum test were applied for statistical analysis. The level of statistical significance was set at p < .05. RESULTS: Thirty-nine Mono-ZrO2 and 37 PFM crowns were delivered. At the 1y-FU, one crown in each group was lost due to loss of the implant. Technical complications occurred in the PFM group and were limited to four minor ceramic chippings resulting in a total technical complication rate of 11.1% (p = .024). Anatomical form and color match compared to the adjacent dentition were rated significantly inferior for the Mono-ZrO2 crowns. Patient satisfaction was high in both groups at BL (34 Mono-ZrO2 34 PFM) and at 1y-FU (36 Mono-ZrO2 31 PFM). No significant differences between the groups were detected with respect to the change in MBL and to the soft tissue parameters. CONCLUSIONS: Monolithic zirconia crowns are a similarly successful alternative option to PFM crowns for restoring single implants in the posterior area.

The Why, What, How and What if-The method to present your research and clinical cases.

BACKGROUND: During the fourth Summer Camp (SC) held by the European Association of Osseointegration (EAO), 20 junior representatives from various European and non-European universities and associations were selected to partake in oral presentation and communication skill development. AIMS: The aim of the EAO Summer Camp (EAO SC) was to identify new methods of enhancing participants' abilities to engage, influence and lead in a professional environment, on both a clinical and scientific level. MATERIALS AND METHODS: Four different groups were assigned to discuss one of two topics: (1) an Implant Register and (2) Digital Dentistry. The method that was used during the EAO SC, for training presentation skills, was the 4MAT learning model. The 4MAT learning model is a framework for creating an engaged, dynamic and more involved style of training by accurately visualizing the learning process that each learner goes through. RESULTS AND CONCLUSIONS: All four groups, including each participant, presented outcomes in the format of 4MAT learning model answering four key questions, the Why, the What, the How and the What if. After the event, each group prepared a written summary of the thought processes. The outcome of the summer camp, for the chosen participants, was gaining skills to engage and influence in a professional environment, both clinically and scientifically. It was also expected from participants to share gained knowledge in their own respective environments after the EAO Summer Camp had ended. In conclusion, most of participants gained a valuable insight into presentation skills and also demonstrated their enthusiasm by presenting their experience at universities, institutes and clinics.

Soft tissue augmentation applying a collagenated porcine dermal matrix during second stage surgery: A prospective multicenter case series.

BACKGROUND: The achievement and preservation of an adequate amount of soft tissue around implants is a critical factor for the prognosis of the treatment. PURPOSE: To evaluate the effectiveness of a porcine dermal matrix applied during second stage implant surgery for horizontal soft tissue augmentation and preservation of dimensional stability. MATERIALS AND METHODS: Twenty patients (mean age 50.2 ± 11.9 [SD] years) candidate to implant therapy and requiring soft tissue augmentation were recruited in four centers. Augmentation was performed in 24 cases. A porcine dermal matrix was placed into a buccal split-thickness pouch during uncovering surgery. Silicone impressions were taken before surgery (T0), 2 weeks later at suture removal (T2), 6 months (T3), and 24 months (T4) post augmentation. Dimensional changes of soft tissue were evaluated using superimposition of digitalized study casts. RESULTS: Nineteen patients (23 implants) could be evaluated at 6 months and 13 patients (17 implants) at 24 months. After 6-month follow-up, there was a significant dimensional gain respect to baseline, averaging 0.83 ± 0.64 mm (P < .01). This did not change significantly at 24 months (0.77 ± 0.65 mm, P = .19). The gain was >0.5 mm in 65.2% and 64.7% of the cases, respectively. Soft tissue shrinkage averaged 34.2% ± 77.0% from T2 to T3 (P < .01) and did not change thereafter (P = .39). Shrinkage was more consistent in the posterior mandible than in the maxilla, but not significantly (P = .23 at 6-month and .36 at 24-month). No adverse events occurred. CONCLUSION: Within the limitations of this prospective case series, the use of a porcine dermal matrix may provide consistent soft tissue augmentation that maintains up to 24-month follow-up, although graft shrinkage may occur in the first 6 months, depending on the location of surgery.

A Randomized Controlled Clinical Trial Comparing Conventional and Computer-Assisted Implant Planning and Placement in Partially Edentulous Patients. Part 4: Accuracy of Implant Placement.

The objective of this study was to compare the accuracy of conventional and computer-assisted implant planning and template-guided placement (CAIPP) protocols. Partially edentulous patients (N = 73) were randomly assigned to either a conventional implant planning and freehand placement protocol (control group, n = 26) or one of two different CAIPP protocols (stereolithographic guide [T1, n = 24] or 3D-printed guide [T2, n = 23]). The virtually planned and final implant positions were compared. Differences between the planned and the obtained implant position were evaluated as horizontal, vertical, and angular measurements. Descriptive statistics were calculated for overall deviation values and their fragmented mesiodistal and bucco-oral vectors at each evaluation plane. To study overall accuracy differences between study groups, analysis of variance (ANOVA) was used with Bonferroni post hoc test (Scheffé method). Possible confounding variables were analyzed using multiple linear regression with respect to treatment group. The mesiodistal or bucco-oral distribution of the positioning errors was evaluated with chi-square test. A multiple linear logistic regression was used to identify confounding variables. Inaccuracy at the level of the occlusal plane of the restoration averaged 0.65 ± 0.26 mm in the control group, 0.59 ± 0.4 mm in T1, and 0.76 ± 0.5 mm in T2. At the implant shoulder level, the inaccuracy amounted to 1.25 ± 0.62 mm, 0.97 ± 0.36 mm, and 0.72 ± 0.31 mm in the control group, T1, and T2, respectively. At the implant apex, mean deviations of 2.32 ± 1.24 mm were recorded in the control group, 0.97 ± 0.57 mm in T1, and 1.08 ± 0.57 mm in T2. Mean discrepancies in vertical direction measured 0.28 ± 1.01 mm (control), 0.2 ± 0.65 mm (T1), and -0.1 mm ± 1.0 mm (T2). Angular deviations of 7.36 ± 3.36 degrees (control), 4.23 ± 2.68 degrees (T1), and 3.13 ± 2.12 degrees (T2) were measured. Statistically significant differences were observed between the conventional and the two CAIPP groups for overall deviations at implant shoulder, apex, and implant angulation. CAIPP protocols seemed to provide a higher accuracy and precision compared to conventional freehand protocols. Still, the amount of inaccuracy using guides demands a safety margin. Moreover, intrasurgical verification during drilling and the implant placement procedure should be performed, including clinical parameters that may not be available from cone beam computed tomography data during the planning phase.