Erratum: Sleeveless guided implant placement compared to conventional approaches: An in vitro study at healed sites and fresh extraction sockets

The following amendments are made to the published article: Int J Oral Implantol (Berl) 2023;16(2): 117-132; First published 9 May 2023.

Digitally-Guided Lateral Sinus Floor Elevation with Simultaneous Implant Placement: Three Case Reports with Technical Considerations

INTRODUCTION

A sinus floor elevation via lateral window (LSFE) is one of the most widely used bone augmentation procedures for implant therapy in the posterior area of the maxilla.  Locating and preparing a correct opening window on the lateral sinus wall is a key step of this procedure. Conventionally, the surgeon design and locate the window after the flap is reflected based upon the information obtained from cone-beam computed tomography (CBCT) images or other diagnostic aids. Nevertheless, in spite of the advancements in CBCT imaging, clinicians may still experience hardship in situating and procuring meticulous access to the maxillary sinus by using CBCT alone. Therefore, in cases requiring a LSFE simultaneous to implant placement, a maxillary sinus surgical guide (MSSG) has been tested and reported to be the amiable method to be utilized as a conjunct, to prevent unpredictable consequences according to its application in implying both the direction for the implant and the location of the lateral window.

CASE SERIES

This article presents 3 clinical cases with a fully digital approach to guide the opening of the lateral wall of the maxillary sinus, as well as the simultaneous placement of a single implant in an ideal 3D position. Based on the CBCT images and intraoral scan, a surgical guide was fabricated base on 3D software. During the surgery, this teeth-supported template can be placed intraorally, guiding sinus window opening preparation.

CONCLUSION

This technique makes the sinus window opening procedure simple and predictable, reduces surgical time as well as the risk of complications, and allows the placement of the implant in the ideal 3D position.

Sleeveless guided implant placement compared to conventional approaches: An in vitro study at healed sites and fresh extraction sockets

PURPOSE

To investigate the accuracy of a novel sleeveless implant surgical guide by comparing it with a conventional closed-sleeve guide and a freehand approach.

MATERIALS AND METHODS

Custom resin maxillary casts with corticocancellous compartments were used (n = 30). Seven implant sites were present per maxillary cast, corresponding to healed (right and left first premolars, left second premolar and first molar) and extraction sites (right canine and central incisors). The casts were assigned into three groups: freehand (FH), conventional closed-sleeve guide (CG) and surgical guide (SG) groups. Each group comprised 10 casts and 70 implant sites (30 extraction sites and 40 healed sites). Digital planning was used to design 3D printed conventional and surgical guide templates. The primary study outcome was implant deviation.

RESULTS

At extraction sites, the largest difference between groups occurred in angular deviation, where the SG group (3.80 ± 1.67 degrees) exhibited ~1.6 times smaller deviation relative to the FH group (6.02 ± 3.44 degrees; P = 0.004). The CG group (0.69 ± 0.40 mm) exhibited smaller coronal horizontal deviation compared to the SG group (1.08 ± 0.54 mm; P = 0.005). For healed sites, the largest difference occurred for angular deviation, where the SG group (2.31 ± 1.30 degrees) exhibited 1.9 times smaller deviation relative to the CG group (4.42 ± 1.51 degrees; P < 0.001), and 1.7 times smaller deviation relative to the FH group (3.84 ± 2.14 degrees). Significant differences were found for all parameters except depth and coronal horizontal deviation. For the guided groups, there were fewer significant differences between healed and immediate sites compared to the FH group.

CONCLUSION

The novel sleeveless surgical guide showed similar accuracy to the conventional closed-sleeve guide.

A fully digital approach for implant fixed complete dentures: A case report

INTRODUCTIONS

Intraoral scanner has been widely used for implant impression in partially edentulous cases; however, its accuracy in the impression of full-arch implant is still questionable.

CLINICAL REPORT

This clinical report presents a technique to check the accuracy of intraoral scanning for complete-arch implant restorations using an implant index cast (The Glossary of Prosthodontic Terms 9th Edition) and a three-dimensional printed cast. A clinical case of immediate loading on a maxillary edentulous patient illustrates the application of an implant index cast in implant fixed complete dentures (IFCDs).

DISCUSSION

The implant index cast was fabricated based on the immediate interim prosthesis and provides effective control of the fit of scanned files and printed models. Therefore, this approach allows a more predictable and accurate fit of the final prosthesis.

CLINICAL SIGNIFICANCE

In this article, we present a technique to check the accuracy of the final prosthesis without the need for a conventional impression and final cast in a digital workflow. This proposed approach is demonstrated through a case report of a maxillary edentulous patient restored with immediate loaded IFCDs.

The Impact of Surgical Guide Fixation and Implant Location on Accuracy of Static Computer-Assisted Implant Surgery

PURPOSE

To evaluate the accuracy of static computer-assisted implant surgery (sCAIS) for tooth-supported free-end dental implantation with the aid/and without the aid of fixation pins to secure the surgical template through comparison between planned, 3D printed guide position and placement implant position.

MATERIALS AND METHODS

Thirty-two duplicated maxillary resin models were used in the present in vitro study. Digital planning was performed and fabrication of a surgical template that allowed implant placement on the distal extension edentulous site of the model (maxillary left side). A first optical scan was performed after fitting the surgical template on the model to assess the deviation at the surgical guide level. After placing implants in the model using the surgical guide, scan bodies were attached to the implants, and a second scan was performed to record the position of placed implants. The digital representations were later superimposed to the pre-operative scan and measurements of implant deviations were performed. Global (coronal and apical), horizontal (coronal and apical), depth and angular deviations were recorded between planned implant position, guide position, and placement implant position. Three-way ANOVA was used to compare implant location (#13, 14, and 15), fixation pin (with or without pin), and guide comparison (planned, guided, and placement).

RESULTS

Final implant placement based on the digital plan and based on the 3D printed guide were very similar except for depth deviation. Use of fixation pin had a statistically significant effect on the depth and angular deviation. Overall, without fixation pins and based on guide versus placement, mean global coronal (0.88 ± 0.36 mm), horizontal coronal (0.55 ± 0.32 mm), and apical (1.44 ± 0.75 mm), and angular deviations (4.28 ± 2.01°) were similar to deviations with fixation pins: mean global coronal (0.88 ± 0.36 mm); horizontal coronal (0.67 ± 0.22 mm) and apical (1.60 ± 0.69 mm); and angular deviations (4.53 ± 2.04°). Horizontal apical without pins (1.63 ± 0.69 mm) and with fixation pins (1.72 ± 0.70 mm) was statistically significant (p = 0.044). Depth deviation without pins (-0.5 ± 0.5 mm) and with fixation pins (-0.16 ± 0.62 mm) was also statistically significant (p = 0.005). Further analysis demonstrated that the final sleeve position on the 3D printed guide was on average 0.5 mm more coronal than the digital plan.

CONCLUSIONS

The use of surgical guides with or without fixation pins can provide clinically acceptable outcomes in terms of accuracy in implant position. There was a statistically significant difference in the accuracy of implant position when utilizing fixation pins only for horizontal apical and depth deviation. Additionally, a statistically significant difference between the planned and the 3D printed surgical guide when considering the sleeve position was detected.

Synthesis and Characterization of Styrene-Butadiene Rubber-Clay Nanocomposites with Enhanced Mechanical and Gas Barrier Properties

Five styrene-butadiene rubber (SBR)/clay nanocomposite or hybrid systems were synthesized via mechanical mixing of SBR using a Brabender mixer and a 2-roll mill in the presence of unmodified sodium montmorillonite (Na-MMT) clay, MMT modified with octadecylamine (C18amine), MMT modified with a zwitterionic surfactant, octadecyldimethyl betaine (C18DMB), and MMT modified with a polymerizable cationic surfactant, vinylbenzyl octadecyldimethyl ammonium chloride (VODAC) or vinylbenzyl dodecyldimethyl ammonium chloride (VDAC). The surfactant chain length and functional groups affected the dispersion of clay nanolayers in the matrix and the overall properties of the nanocomposites. X-ray diffraction (XRD) revealed peaks corresponding to intercalated structures; transmission electron microscopy (TEM) observations agreed well with XRD assessment of the composites. SBR/VODAC-MMT system exhibited the best dispersion among the nanocomposites studied. VODAC-MMT was partially exfoliated in SBR matrix and the average aspect ratio of the nanolayer stacks or aggregates was high (20). Depending on the amount of clay, considerable mechanical reinforcement and gas barrier enhancement were achieved in nanocomposites over pure rubber. Tensile strength in excess of 18MPa was observed in SBR nanocomposites with 30 phr C18 organoclays. The storage modulus at 25C increased by a factor of four by incorporating 10 phr VODAC-MMT in SBR. The most pronounced oxygen barrier enhancement was again observed in SBR/VODAC-MMT nanocomposite with the reduction of permeability by 60% at silicate volume fraction of 0.06. The superior performance of nanocomposites containing VODAC-MMT is attributed to the presence of the vinyl-benzyl group and 18 carbon-atom tail in the surfactant leading to high compatibility with SBR and nano-scale dispersion in the SBR matrix.

Impact of harmonic imaging on transthoracic echocardiographic identification of infective endocarditis and its complications

OBJECTIVE

To evaluate the comparative diagnostic value of harmonic imaging (HI) in the assessment of patients with suspected infective endocarditis (IE).

SETTING

Tertiary referral centre.

DESIGN

139 consecutive patients were evaluated with three imaging modalities: transthoracic echocardiography with fundamental imaging (FI); HI; and transoesophageal echocardiography (TOE). Image quality was assessed for each modality by semiquantitative scoring (0, poor, to 3, excellent). Presence, dimension, and characteristics of vegetations were assessed separately for each imaging modality, as well as presence of abscesses.

RESULTS

35 patients had definite IE. TOE was positive in 33 patients, HI in 28, and FI in 12 (p < 0.001 for FI v HI and v TOE). Mean image quality was 1.4 (0.7) for FI, 2.1 (0.6) for HI (p < 0.01 v FI), and 2.6 (0.4) for TOE (p < 0.001 v HI). The association between FI and TOE findings was Phi = 0.35 (chi2 = 17.57, p = 0.0014) and between HI and TOE it was Phi = 0.95 (chi2 = 125.72, p < 0.0001; p < 0.0001 v FI). The global echo score of vegetations was 7.1 (3.3) with FI, 8.5 (3.4) with HI, and 11.3 (3.9) with TOE (p < 0.001 v HI). Compared with TOE, FI identified only one of seven abscesses (sensitivity 14%) and HI identified two of seven abscesses (sensitivity 28%).

CONCLUSIONS

HI provides an accurate assessment of suspected IE. TOE achieves superior definition of IE related abnormalities.

In-vitro mechanisms of 1,2-dichloropropane nephrotoxicity using the renal cortical slice model

1. Renal cortical slices isolated from the kidneys of male Wistar rats were used as an experimental model for studying the nephrotoxicity induced by 1,2-dichloropropane. 2. The solvent causes a depletion of renal reduced glutathione content and slight, but significant, lipid peroxidation. The block of the oxidative pathway with carbon monoxide prevents glutathione content depletion, and shows that this conjugation is the major step in 1,2-dichloropropane metabolism. 3. Loss of organic anion accumulation and release into the incubation medium of tubular enzymes, mainly from the soluble fraction, are the toxic effects of the solvent. The brush border is only slightly affected. 4. The mechanism of nephrotoxicity appears to occur via mercapturic acid metabolism. Acivicin and aminooxyacetic acid, inhibitors of gamma-glutamyltransferase and beta-lyase activity, respectively, partially but significantly prevent the loss of organic anion accumulation induced by 1,2-dichloropropane. Furthermore, alpha-ketobutyrate, an activator of beta-lyase, enhances the effects of 1,2-dichloropropane on the target, but is itself toxic for organic anion accumulation.

Sex- and age-related nephrotoxicity due to 1,2-dichloropropane in vitro

Sex- and age-related nephrotoxicity due to 1,2-dichloropropane was studied in vitro by means of renal cortical slices obtained from Wistar rats. Reduced glutathione content, organic anion accumulation (p-aminohippurate), and release of malondialdehyde (to measure the extent of lipid peroxidation), aspartate aminotransferase, gamma-glutamyltransferase and lactate dehydrogenase into the incubation medium were determined. Sex differences in naive rats parameters were slight, but male were more susceptible to toxic effects of 1,2-dichloropropane than female rats; glutathione depletion, lipid peroxidation, and loss of organic anion accumulation were higher in male than in female slices. During senescence, naive male rats showed a progressive decrease of glutathione content (statistically significant from 7-9 months of age), increase of spontaneous lipid peroxidation from the same age, and increase of signs of cytotoxicity (release of aspartate aminotransferase and lactate dehydrogenase into the incubation medium) from 3-4 months of age. A loss of organic anion accumulation started from 7-9 months of age. Slices from rats of 3-4 months old showed the apparently highest susceptibility to 1,2-dichloropropane but depletion of glutathione content and loss of organic anion accumulation were at the same level in the oldest rats. The age decrease of control values caused the differences in the percentage ratio and then, apparently, a lower DCP effect. On the contrary, the increase of aspartate aminotransferase released in the incubation medium by DCP-treated slices corresponded to the age-related increase in cytotoxicity.

[Pollution by nitrous dioxide during diagnostic laparoscopy interventions]

Here we have outlined the data relative to an environmental survey carried out in a laparoscopy clinic at the hospital of Padua, to determine the environmental concentration of nitrous dioxide (N2O) used for intra-abdominal inflation during diagnostic laparoscopy interventions. The data obtained have revealed cases of considerable N2O environmental pollution. This above all, due to spontaneous loss of gas during the intervention and to the lack of adequate ventilation systems.