Comparative microstructural analysis of bone osteotomies after cutting by computer-assisted robot-guided laser osteotome and piezoelectric osteotome: an in vivo animal study

Abstract

Most industrial laser applications utilize computer and robot assistance, for guidance, safety, repeatability, and precision. In contrast, medical applications using laser systems are mostly conducted manually. The advantages can be effective only when the system is coupled to a robotic guidance, as operating by hand does not reach the required accuracy. We currently developed the first laser osteotome which offers preoperative planning based on CT data, robot guidance, and a precise execution of the laser cuts. In an animal trial, our system was used to create a grid pattern of the same depth on the inner layer of parietal bone in 12 adult sheep. The same bone cuts were done with piezoelectric osteotome on the contralateral side. The micro-CT and histological analysis showed more new mineralized bone in the laser group compared to the piezoelectric group. As well, a cutting pattern with especially a constant osteotomy depth in the laser group was demonstrated. The here presented autonomous osteotomy tool shows not only an advantage in early bone healing stage but additionally sharp bone cuts with a very high accuracy and freely selectable design cuts.

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Comparison of gingival depigmentation with Er,Cr:YSGG laser and surgical stripping, a 12-month follow-up

Abstract

Gingival melanin hyperpigmentation is an esthetic concern for many individuals. In this study, we compared the standard surgical removal method with two different Er,Cr:YSGG laser settings in order to find the best treatment method. In 33 dental arches, the following three treatment groups were comparatively evaluated: (1) surgical stripping, (2) removal with laser setting 1 (4.5 W, 50 Hz, 100% water, 80% air, 60 μs, 800 μm Tip; MZ8), and (3) laser setting 2 (2.5 W, 50 Hz, 20% water, 40% air, 700 μs, 800 μm Tip; MZ8). We comparatively evaluated pain, patient satisfaction and wound healing, treatment time, and the amount of bleeding. Re-pigmentation was evaluated after 1 and 12 months by Hedin and Dummet pigmentation scores. Laser setting 1 had the best results regarding pain and patient satisfaction, although not statistically significant (P > 0.05). Wound healing results were better using lasers compared to surgical stripping (P < 0.05). Laser setting 1 was a faster procedure with mild amounts of bleeding. The least amount of bleeding was seen with laser setting 2. After 1 month, only two cases of the laser setting 2-treated areas showed an isolated pigmented area in the papilla; at 12 months, the mean Hedin indexes were still less than 2 and mean Dummett index less than 1 in all treatment techniques, with the lowest scores seen in the laser setting 1 sites. Based on our results, Er,Cr:YSGG laser can be more convenient for gingival depigmentation compared to surgical blade. Although not statistically significant, laser setting 1 with shorter pulse duration and higher water spray showed better overall results. However, laser setting 2, with longer pulse duration and less water spray, resulted in better coagulative effects and can be used to control bleeding wherever necessary in clinical practice.

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Physical, chemical, and biological properties of white MTA with additions of AlF 3

Abstract

Objectives

Addition of aluminum fluoride (AlF₃) to MTA was tested to inhibit dental discoloration.

Materials and methods

MTA Angelus with 0, 5, 15, and 45% AlF₃ were tested. The set cements were characterized using scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. Radiopacity and setting time were analyzed according to ANSI/ADA 57 and ASTM C266-08. Volume change was evaluated using volumetric micro-CT analysis. The pH and calcium ion release were assessed after 3 and 24 h and 28 days. Dental discoloration in contact with the cements was assessed after 24 h and 28 and 90 days of contact with bovine and human dentine. Tissue reaction to subcutaneous implantation in rats was examined after 30 and 60 days.

Results

AlF₃ altered the microstructure of MTA. The addition of 5% AlF₃ did not significantly alter the radiopacity, setting time, and volume change (p > 0.05). pH and calcium ion release significantly increased with addition of AlF₃ (p > 0.05). All the tested proportions of AlF₃ prevented the dental darkening verified for MTA Angelus in bovine and human teeth. AlF₃ did not interfere in inflammatory response of MTA in all periods of analysis; otherwise, lower amounts showed less intense inflammatory infiltrate.

Clinical relevance

AlF₃ prevents destabilization of bismuth oxide and consequent tooth darkening, frequently verified in clinical practice when using white MTA.

Conclusions

The use of 5% of AlF₃ in combination to MTA resulted in a cement that did not result in dental discoloration and did not affect significantly physical, chemical, and biological properties.

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Orbital reconstruction by patient-specific implant printed in porous titanium: a retrospective case series of 12 patients

Publication date: Available online 12 April 2018
Source:Journal of Oral and Maxillofacial Surgery
Author(s): JeanThomas Bachelet, Guillaume Cordier, Matthieu Porcheray, Jerome Bourlet, Arnaud Gleizal, Jean-Marc Foletti
PurposeThe purpose of this study was to evaluate orbital patient specific implant (PSI), directly printed in porous titanium for the reconstruction of complex orbital bone defects, from a series of 12 patients.Patients and MethodsThe investigators designed and implemented a case series. The sample consisted of patients with unilateral complex orbital bone loss. All patients received a porous titanium PSI implantation designed from healthy contralateral side (mirroring). The criteria analyzed were the functional result: enophthalmic correction, ocular motility correction, operative time, complications and operative revisions. The study was done between 2015 and 2017.ResultsThe sample was composed of 12 patients, the mean age of whom was 47 years (range: 13 to 70 years). Patients were followed for a mean 36 weeks post-operatively (range 4 to 100 weeks). Twelve of the twelve patients presented pre-operative enophthalmia, eight of the twelve patients presented pre-operative diplopia. The mean operating time was 71 minutes (range 60 to 200 minutes). For 8 patients, the follow-up was simple, 2 patients required a surgical revision with repositioning of the implant in front of an intraoperative malposition of the implant with aesthetic and / or functional disturbance and a malposition confirmed in the post-operative CT-scan, 1 patient required a withdrawal of his implant 7 months after the surgery in front of spheno-orbital meningioma recidivism (the implant was well positioned), 1 patient operated by sub-ciliary approach presented a post-operative ectropion.In our series of porous titanium orbital PSI without positioning guides, we found 17% of malpositions (2 patients, both patients who required a new intervention for repositioning).ConclusionThe results of this study suggest that porous titanium PSI could be a surgical option of choice for patients with complex orbital bone defect, in our series 17 % of our sample needed a second operation. There are several ways to improve these results, intraoperative navigation, or integrated positioning guides.



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Histological and Histomorphometric response to SocketKAPTM and SocketKAGETM used for Ridge Preservation and Repair: results from a Randomized Controlled Clinical Trial

Publication date: Available online 12 April 2018
Source:Journal of Oral and Maxillofacial Surgery
Author(s): Neema Bakhshalian, Alaa Abdelhamid, Yoon Jeong Park, Homayoun H. Zadeh
PurposeThis study sought to investigate the histological tissue response to SocketKAP and SocketKAGE, as novel devices, designed for ridge preservation.MethodsThis randomized controlled clinical trial recruited participants among patients who presented to a university dental clinic. The study protocol entailed randomization into five intervention groups following tooth extraction: A) Unassisted healing of intact sockets, B) SocketKAP, C) Anorganic bovine bone minerals (ABBM)+SocketKAP, D) Unassisted healing of sockets with dehiscence, and E) SocketKAGE+ABBM+SocketKAP. The primary outcome variable was bone volume fraction (BV/TV). Secondary outcome variables were the percentages of residual graft material (RG) and void volume (VV). One-way analysis of variance was run on BV/TV, RG, and VV, based on the independent variable (the treatment groups).ResultsBone core samples were harvested from subjects (N=22), who presented for implant installation, at 6-months post-extraction. Sockets without biomaterial filler, Groups A and B, showed more mature bone, compared to grafted sockets. In groups where sockets were filled with biomaterial (groups C and E), vital bone was observed in direct apposition to the graft particles. In group E, remnants of SocketKAGE were not readily discernable at 6 months. No substantial inflammatory infiltrate or other adverse histologic patterns were detected. Quantitative analysis showed a statistically significant difference in BV/TV between groups A and C (p=0.028), as well as between groups A and E (p=0.019).ConclusionsHistological and histomorphometric results showed that the application of SocketKAP and SocketKAGE did not interfere with wound healing of extraction sockets. In agreement with previous reports, the percentage of BV/TV within sites with ABBM was lower than sites without biomaterial. The favorable histologic response to SocketKAP and SocketKAGE observed in the present study, provided additional insights to our previous studies demonstrating the benefits of these devices in reducing post-extraction dimensional alterations of alveolar bone and tissue contour.



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Solitary Plasmacytoma of Frontal Bone: A Case Report

Abstract

A 42 years old male presenting with complaints of swelling on the left supraorbital region since—5 months. Swelling was gradual in onset and progressive in nature. On examination it was a single swelling 5 × 6 cm, with diffuse margins, skin over the swelling was red and stretched, swelling is firm in consistency, fixed, tender on touch, non pulsatile with diffuse irregular margin. FNAC. Smears are positive for malignancy. Bone marrow examination was normal. Excision of the mass from the left frontal sinus, orbit and supraorbital region under GA and sent for HPR. Definitive treatment of choice is: radiotherary 45–50 Gy/4–5 weeks, chemotherapy and surgery. Prognosis is good with local recurrence (< 10%).

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Congenital Cholesteatoma in Adults-Interesting Presentations and Management

Abstract

To report a series of adult patients diagnosed with congenital cholesteatoma (CC) with respect to symptoms, different varieties of presentation, surgical findings and approach used, complications and the postoperative results. A retrospective chart review of adult cases of CC who were treated in the period from January 2014–2017 was carried out in a tertiary care center. Levenson's criteria were used for diagnosis. Diagnosis was confirmed by imaging and intraoperatively. Postoperative results and complications were also analyzed. Six adult cases of CC were studied with a mean follow up of 10 months. Interesting presentations included otitis media with effusion, non-resolving facial nerve palsy, post aural discharge and meningitis. It included 3 cases of petrous apex cholesteatoma, 2 patients with cholesteatoma involving both the middle ear and mastoid and 1 patient with mastoid cholesteatoma. The operative procedures included canal wall up mastoidectomy (1 patient), atticotomy (1 patient), canal wall down mastoidectomy (1 patient), translabyrinthine and transotic excision of mass with blind sac closure (2 patients) and partial labyrinthectomy (1 patient). Complications encountered during surgery were cerebrospinal fluid leak and worsening of hearing in 2 patients and 1 patient respectively. CC can have variety of interesting presentations in adult population and they may or may not have the classical white mass behind the tympanic membrane. Appropriate individualized surgical planning and intervention gives good results.

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