Schneiderian membrane perforation via transcrestal sinus floor elevation: A randomized ex vivo study with endoscopic validation

ObjectiveTo endoscopically determine the incidence of Schneiderian membrane perforation during transcrestal maxillary sinus floor elevation (SFE), in relation to the bone preparation technique, amount of bone graft, membrane elevation height and different surgical steps.Materials and methodsSeven cadaver heads corresponding to 12 maxillary sinuses were used to perform three SFE via transcrestal approach per sinus (36 elevations). Each sinus was randomly assigned to either the Sinus Crestal Approach (SCA) drill kit technique (experimental group) or the conventional osteotome technique (control group). During all phases of the surgery, the integrity of the sinus membrane was monitored through endoscopic examination.ResultsA significant difference was found in the incidence of perforation (p = 0.007) and vertical elevation height (p < 0.001) between the study groups, favoring the experimental group. A safety elevation threshold of 5 mm without bone graft and implant placement was estimated. A significant correlation was observed between the residual ridge height and the incidence of perforation (p < 0.001; OR = 0.51).ConclusionThe SCA drill kit may demonstrate superior osteotomy preparation and membrane elevation capabilities to the osteotome technique, and significantly when a 6â mm SFE is indicated. Residual ridge height and vertical elevation height are risk determinant factors.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147768/1/clr13388_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147768/2/clr13388.pd

Accuracy of flapless immediate implant placement in anterior maxilla using computerâ assisted versus freehand surgery: A cadaver study

ObjectiveTo compare the accuracy of computerâ guided surgery and freehand surgery on flapless immediate implant placement (IIP) in the anterior maxilla.Material and MethodsIn this splitâ mouth design, 24 maxillary incisors in eight human cadaver heads were randomly divided into two groups: computerâ guided surgery (n = 12) and freehand surgery (n = 12). Preoperatively, coneâ beam computed tomography (CBCT) scans were acquired, and all implants were planned with a software (Blue Sky Plan3). Then, two types of surgeries were performed. To assess any differences in position, the postoperative CBCT was subsequently matched with the preoperative planning. For all the implants, the angular, global, depth, buccoâ lingual, and mesioâ distal deviations between the virtual and actual implant positions were measured.ResultsA significant lower mean angular deviation (3.11 ± 1.55°, range: 0.66â 4.95, p = 0.002) and the global deviation at both coronal (0.85 ± 0.38 mm, range: 0.42â 1.51, p = 0.004) and apical levels (0.93 ± 0.34 mm, range: 0.64â 1.72, p < 0.001) were observed in the guided group when compared to the freehand group (6.78 ± 3.31°, range: 3.08â 14.98; 1.43 ± 0.49 mm, range: 0.65â 2.31, and 2.2 ± 0.79 mm, range: 1.01â 4.02). However, the accuracy of these two approaches was similar for the depth (p = 0.366). In the buccal direction, the mean deviations of both groups showed a general tendency of implants to be positioned facially, occurring more in implants of the freehand group.ConclusionIn flapless IIP, computerâ guided surgery showed superior accuracy than freehand surgery in transferring the implant position from the planning. However, even with the help of a guide, the final fixture position tends to shift toward a facial direction.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146997/1/clr13382_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146997/2/clr13382.pd

Ultrasonography for chairside evaluation of periodontal structures: A pilot study

BackgroundThe crestal bone level and soft tissue dimension are essential for periodontal diagnosis and phenotype determination; yet, existing measurement methods have limitations. The aim of this clinical study was to evaluate the correlation and accuracy of ultrasound in measuring periodontal dimensions, compared to direct clinical and cone- beam computed tomography (CBCT) methods.MethodsA 24- MHz ultrasound probe prototype, specifically designed for intraoral use, was employed. Periodontal soft tissue dimensions and crestal bone levels were measured at 40 teeth and 20 single missing tooth gaps from 20 patients scheduled to receive a dental implant surgery. The ultrasound images were interpreted by two calibrated examiners. Inter- rater agreement was calculated by using inter- rater correlation coefficient (ICC). Ultrasound readings were compared with direct clinical and CBCT readings by using ICC and Bland- Altman analysis.ResultsThe following six parameters were measured: 1) interdental papilla height (tooth), 2) mid- facial soft tissue height (tooth), 3) mucosal thickness (tooth), 4) soft tissue height (edentulous ridge), 5) mucosal thickness (edentulous ridge), and 6) crestal bone level (tooth). Intra- examiner calibrations were exercised to achieve an agreement of at least 0.8. ICC between the two readers ranged from 0.482 to 0.881. ICC between ultrasound and direct readings ranged from 0.667 to 0.957. The mean difference in mucosal thickness (tooth) between the ultrasound and direct readings was - 0.015 mm (95% CI: - 0.655 to 0.624 mm) without statistical significance. ICC between ultrasound and CBCT ranged from 0.654 to 0.849 among the measured parameters. The mean differences between ultrasound and CBCT range from - 0.213 to 0.455 mm, without statistical significance.ConclusionUltrasonic imaging can be valuable for accurate and real- time periodontal diagnosis without concerns about ionizing radiation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156207/2/jper10483_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156207/1/jper10483.pd

The Effect of Locally Delivered Statins on Treating Periodontal Intrabony Defects: A Systematic Review and Metaâ Analysis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142319/1/jper0357.pd

Incidence of retrograde peri- implantitis in sites with previous apical surgeries: A retrospective study

BackgroundRetrograde peri- implantitis (RPI) is a rapidly progressing periapical infection that forms around the implant apex. It is usually associated with sites adjacent to teeth with apical lesions; previous endodontic failures, retained root fragments, etc. This study aimed to study the incidence of RPI in sites with a history of apical surgeries.MethodsPatients with sites treated for both apicoectomy and implant placement presenting to the University of Michigan School of Dentistry from 2001 to 2016 were screened. A total of 502 apicoectomies were performed, only 25 of these fit the predetermined eligibility criteria and were thus included in this retrospective analysis.ResultsImplants that were placed in sites with a previous apical surgery had a cumulative survival rate of 92%. The incidence of peri- implantitis was 8%, while the incidence of RPI was 20%. There was an increased trend for RPI in cases where the cause of extraction was persistent apical periodontitis (35.7%), but this increase didn’t reach the level of statistical significance (P = 0.061).ConclusionImplants placed in sites with previous apical surgery are not at an increased risk of implant failure or RPI.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166204/1/jper10576_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/166204/2/jper10576.pd

Comprehensive peri- implant tissue evaluation with ultrasonography and cone- beam computed tomography: A pilot study

ObjectivesThe aim of the present study was to explore the feasibility of ultrasonography (US) for clinical imaging of peri- implant tissues.Material and MethodsPatients with - ¥1 implant, a cone- beam computed tomography (CBCT) scan, an US scan, and clinical photographs taken during the surgery were included. The crestal bone thickness (CBT) and facial bone level (FBL) were measured on both US and CBCT modalities, and direct FBL measurements were also made on clinical images. US measurements were compared with CBCT and direct readings.ResultsA total of eight implants from four patients were included. For FBL measurements, US and direct (r2 = 0.95) as well as US and CBCT (r2 = 0.85) were highly correlated, whereas CBCT correlated satisfactorily with the direct reading (r2 = 0.75). In one implant without facial bone, CBCT was not able to measure CBT and FBL accurately. The estimated bias for CBT readings was 0.17 ± 0.23 mm (p = .10) between US and CBCT. US blood flow imaging was successfully recorded and showed a wide dynamic range among patients with different degrees of clinical inflammation.ConclusionUS is a feasible method to evaluate peri- implant facial crestal bone dimensions. Additional US features, for example, functional blood flow imaging, may be useful to estimate the extent and severity of inflammation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/168434/1/clr13758_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/168434/2/clr13758.pd

Does flap opening or not influence the accuracy of semiâ guided implant placement in partially edentulous sites?

ObjectiveTo investigate the effect of openâ flap or flapless approaches on the accuracy of implant placement partially guided by toothâ supported surgical templates.Materials and MethodsA total of 36 edentulous sites were selected from seven human cadaver heads. Following the preoperative implant planning using Blue Sky Plan, surgical guides were fabricated by an inâ office desktop 3D printer. All the sites were randomly divided into two groups: flapless approach (n = 18), and openâ flap approach (n = 18). After guided osteotomy preparation with subsequent freehand implant placement, digital intraoral scanning was performed to obtain postâ operative implant positions. Based on the image registration, the deviations between the planned and actual implant position were measured and compared.ResultsStatistically significant variance differences between the two approaches were found in the global coronal (openâ flap: 0.86â ±â 0.23â mm; flapless: 1.3â ±â 0.62â mm; Pâ <â .001), global apical (openâ flap: 1.38â ±â 0.37â mm; flapless: 1.9â ±â 0.78â mm; P = .002), and depth (openâ flap: 0.59â ±â 0.34â mm; flapless 0.89â ±â 0.78â mm; Pâ <â .001) deviations. The differences were not significant regarding lateral (coronal and apical) and angular deviations.ConclusionsIn semiâ guided implant surgery, the openâ flap and flapless approaches demonstrate similar lateral and angular deviations. The openâ flap group shows better depth control when manually inserting the implant.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152996/1/cid12847.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152996/2/cid12847_am.pd

Non-invasive evaluation of facial crestal bone with ultrasonography.

PURPOSE:Facial crestal bone level and dimension determine function and esthetics of dentition and dental implants. We have previously demonstrated that ultrasound can identify bony and soft tissue structures in the oral cavity. The aim of this study is to evaluate the accuracy of using ultrasound to measure facial crestal bone level and thickness. MATERIALS AND METHODS:A commercially available medical ultrasound scanner, paired with a 14 MHz imaging probe was used to scan dental and periodontal tissues at the mid-facial site of each tooth on 6 fresh cadavers. The alveolar crest level in relation to the cemento-enamel junction and its thickness on ultrasound images were measured and compared to those on cone-beam computed tomography (CBCT) scans and/or direct measurements on a total of 144 teeth. RESULTS:The mean crestal bone level measured by means of ultrasound, CBCT and direct measures was 2.66 ± 0.86 mm, 2.51 ± 0.82 mm, and 2.71 ± 1.04 mm, respectively. The mean crestal bone thickness was 0.71 ± 0.44 mm and 0.74 ± 0.34 mm, measured by means of ultrasound and CBCT, respectively. The correlations of the ultrasound readings to the other two methods were between 0.78 and 0.88. The mean absolute differences in crestal bone height and thickness between ultrasound and CBCT were 0.09 mm (-1.20 to 1.00 mm, p = 0.06) and 0.03 mm (-0.48 to 0.54 mm, p = 0.03), respectively. CONCLUSION:Ultrasound was as accurate in determining alveolar bone level and its thickness as CBCT and direct measurements. Clinical trials will be required to further validate this non-ionizing and non-invasive method for determining facial crestal bone position and dimension

Correlations of bone level and thickness readings between 3 estimation methods.

<p>Correlations of bone level and thickness readings between 3 estimation methods.</p