Digitally Guided Lateral Sinus Floor Elevation With Simultaneous Implant Placement: 3 Case Reports With Technical Considerations

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 designs and locates the window after the flap is reflected based on 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 hardships in situating and procuring meticulous access to the maxillary sinus by using CBCT alone. Therefore, in cases requiring an LSFE simultaneous to implant placement, a maxillary sinus surgical guide 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. 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 based on 3D software. During surgery, this teeth-supported template can be placed intraorally, guiding sinus window opening preparation. This technique makes the sinus window opening procedure simple and predictable, reduces surgical time and the risk of complications, and allows the placement of the implant in the ideal 3D position.

Effects of crown contour on artificial biofilm removal efficacy with interdental cleaning aids: An in vitro study

OBJECTIVES

To evaluate the efficacy of various interdental cleaning aids for artificial biofilm removal on different implant-supported crown designs.

METHODS

Mandibular models with missing first molar were fabricated and installed with single implant analogs and loaded with crowns of different designs (concave, straight, and convex). Artificial biofilm was made with occlusion spray. Thirty volunteers (periodontists, dental hygienists, and laypersons) were asked to clean the interproximal areas. The crowns were unscrewed and photographed in a standardized setting. The outcome was measured by the cleaning ratio which represents the cleaned surfaces in relation to the area of the tested surface.

RESULTS

A significant difference in favor of concave crown (p < .001) on the basal surface was cleaned by all tools, except the water flosser. There was evidence of an overall effect of "cleaning tool," "surface," and "crown design" (p < .0001) except for the "participant" factor. The mean cleaning ratio for each cleaning tool and overall combined surfaces were (in%): dental floss: 43.02 ± 23.93, superfloss: 42.51 ± 25.92, electric interspace brush: 36.21 ± 18.78, interdental brush: 29.10 ± 15.95, and electric water flosser: 9.72 ± 8.14. Dental floss and superfloss were significantly better (p < .05) than other tools in removing plaque.

CONCLUSIONS

Concave crown contour had the greatest artificial biofilm removal, followed by straight and convex crowns at the basal surface. Dental floss and superfloss were the most effective interdental cleaning devices for artificial biofilm removal. None of the tested cleaning devices were able to completely remove the artificial biofilm from the interproximal/basal surfaces.

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.

Exercise training decreases oxidative stress in skeletal muscle of rats with pulmonary arterial hypertension

The effects of exercise training on oxidative stress in gastrocnemius of rats with pulmonary hypertension were studied. Four groups were established: sedentary control (SC), sedentary monocrotaline (SM), trained control (TC), trained monocrotaline (TM). Exercise was applied for 4 weeks, 5 days/week, 50-60 min/session, at 60% of VO₂ max. Right ventricular (RV) pressures were measured, heart and gastrocnemius were removed for morphometric/biochemical analysis. Lipid peroxidation (LPO), H₂O₂, GSH/GSSG, and activity/expression of antioxidant enzymes were evaluated. Increased RV hypertrophy, systolic and end-diastolic pressures (RVEDP) were observed in SM animals, and the RVEDP was decreased in TM vs. SM. H₂O₂, SOD-1, and LPO were higher in the SM group than in SC. In TM, H₂O₂ was further increased when compared to SM, with a rise in antioxidant defences and a decrease in LPO. GSH/GSSG was higher only in the TC group. Exercise induced an efficient antioxidant adaptation, preventing oxidative damage to lipids.

The Prosthetic-Biologic Connection and Its Influence on Peri-implant Health: An Overview of the Current Evidence

Prosthetic design is a critical step in implant treatment planning that must synchronize with implant positioning to promote a state of peri-implant health. Improperly designed prostheses may not only hinder patient (or professional) hygiene measures but also impact the ability of clinicians to examine the peri-implant supporting tissues for diagnostic purposes. The purpose of this review was to discuss the current state of the evidence surrounding prosthetic factors associated with peri-implant diseases. Following the chronologic order of implant treatment, key prosthetic variables were discussed in relation to peri-implant disease pathogenesis. Specific concepts including the impact of implant spatial positioning, abutment height, residual cement, and implant splinting were found to be associated with peri-implant disease pathogenesis. Excessive occlusal forces were found to play a role in susceptibility to prosthetic complications with limited evidence to suggest a role in peri-implant disease progression. An intimate prosthetic-biologic connection exists, which must be respected to promote an environment for long-term peri-implant stability and health.

Three-Dimensional Volumetric Analysis of the Palatal Donor Site Following Soft Tissue Harvesting

Autogenous soft tissue grafting is a commonly performed procedure in periodontal and implant surgery. Reharvesting a connective tissue graft (CTG) from the same palatal donor site is often required, but little is known about the volumetric changes that occur after harvesting a free gingival graft and how long the palatal mucosa takes to regain its original form and thickness. This study evaluated the volumetric changes that occur at the palatal donor site after harvesting a soft tissue graft with a noninvasive digital technology. Nineteen patients needing a CTG for a single site were enrolled. Intraoral digital scans of the palatal donor sites were obtained at baseline and at 1, 3, 6, and 12 months. The digital scans were imported and analyzed with an imaging software to evaluate volumetric changes. Average volume losses of 5.82 ± 2.63 mm³ and 11.03 ± 5.47 mm³ were observed after 1 and 3 months, respectively. Only minor changes were observed at 6 and 12 months. Linear dimensional changes at 5 and 7 mm from the gingival margin were substantially higher than the changes at 3 mm for the 1- and 3-month interval comparisons compared to baseline. Graft dimension was associated with volume loss at 1 and 3 months (P < .01). After palatal harvesting, the donor site undergoes volumetric changes, mostly during the first 3 months, and is attenuated thereafter.

Prognostic factors associated with implant loss, disease progression or favorable outcomes after peri-implantitis surgical therapy

BACKGROUND

The treatment of the peri-implantitis remains complex and challenging with no consensus on which is the best treatment approach.

PURPOSE

To examine the key local and systemic factors associated with implant loss, disease progression, or favorable outcomes after surgical peri-implantitis therapy.

MATERIALS AND METHODS

Records of patients treated for peri-implantitis were screened. Patient-, implant- and surgery-related variables on and prior to the day of the surgery were collected (T0: time of peri-implantitis treatment). If the treated implant was still in function when the data was collected, the patient invited to participate for a recall study visit (T1, longest follow-up after treatment). Impacts of the variables on the implant survival, success, and peri-implant bone change after treatment were investigated.

RESULTS

Eighty patients with 121 implants with a mean follow-up of 42.6 ± 26.3 months were included. A total of 22 implants (18.2%) were removed during the follow-up period. When relative bone loss (%) was in range 25%-50%, risk for implant removal increased 15 times compared to lower bone loss <25% (OR = 15.2; CI: 2.06-112.7; p = 0.008). Similarly, relative bone loss of >50% increased 20 times the risk of implant failure compared to the <25% (OR = 20.2; CI: 2.42-169.6; p = 0.006). For post-treatment success rate, history of periodontitis significantly increased the risk of unsuccess treatment (OR = 3.07; p = 0.04) after resective surgery).

CONCLUSION

Severe bone loss (>50%) poses significantly higher risk of treatment failure.

Intraoral scanning reduces procedure time and improves patient comfort in fixed prosthodontics and implant dentistry: a systematic review

OBJECTIVES

The primary aim of this systematic review was to evaluate whether intraoral scanning (IOS) is able to reduce working time and improve patient-reported outcome measures (PROMs) compared to conventional impression (CI) techniques, taking into account the size of the scanned area. The secondary aim was to verify the effectiveness of IOS procedures based on available prosthodontic outcomes.

MATERIALS AND METHODS

Electronic and manual literature searches were performed to collect evidence concerning the outcomes of IOS and CI performed during the treatment of partially and complete edentulous patients for tooth- or implant-supported restorations. Qualitative analysis was conducted to evaluate the time efficiency and PROMs produced by the two different techniques. Clinical prosthodontic outcomes were analyzed among the included studies when available.

RESULTS

Seventeen studies (9 randomized controlled trials and 8 prospective clinical studies) were selected for qualitative synthesis. The 17 included studies provided data from 430 IOS and 370 CI performed in 437 patients. A total of 7 different IOS systems and their various updated versions were used for digital impressions. The results demonstrated that IOS was overall faster than CI independent of whether quadrant or complete-arch scanning was utilized, regardless of the nature of the restoration (tooth or implant supported). IOS was generally preferred over CI regardless of the size of the scanned area and nature of the restoration (tooth- or implant-supported). Similar prosthodontic outcomes were reported for workflows implementing CI and IOS.

CONCLUSIONS

Within the limitations of this systematic review, IOS is faster than CI, independent of whether a quadrant or complete arch scan is conducted. IOS can improve the patient experience measured by overall preference and comfort and is able to provide reliable prosthodontic outcomes.

CLINICAL RELEVANCE

Reduced procedure working time associated with the use of IOS can improve clinical efficiency and the patient experience during impression procedures. Patient-reported outcome measures (PROMs) are an essential component of evidence-based dental practice as they allow the evaluation of therapeutic modalities from the perspective of the patient. IOS is generally preferred by patients over conventional impressions.

Analysis In Vivo of Bone Modulation in Hydrophilic and Hydrophobic Titanium Implant Surfaces

PURPOSE

To evaluate whether a hydrophilic surface treatment compared with a hydrophobic implant surface can enhance osseointegration by analysis of calcium deposition, bone-to-implant contact (BIC), bone volume (BV), and upregulation of genes involved in bone formation.

MATERIALS AND METHODS

Sixty implants (n = 60) with a hydrophobic (SAE) or hydrophilic (SAE-HD) surface treatment were placed bilaterally in each femur of 3-month-old male mice (n = 30). Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were utilized for quantifying the presence of calcium on the implant surface 7 days after implant placement. The specimens were analyzed after 14 and 21 days for BIC and BV by Nano CT scanning followed by histologic evaluation. Additionally, 1, 3, and 7 days postsurgery, femurs were harvested, implants were explanted, and gene expression (Sp7, Bsp, Sost, IL-1α, and IL-10) by quantitative real-time polymerase chain reaction was studied. Moreover, implants were characterized for surface roughness area. Data were statistically analyzed with two-way analysis of variance (ANOVA) followed by the Tukey test (P < .05).

RESULTS

The amount of calcium on the surface was higher for SAE-HD after 7 days. Nano CT revealed significantly more BV in the SAE-HD than the SAE surface. The histologic assessment showed increased BIC in SAE-HD in comparison to SAE. SAEHD showed significantly increased levels of genes involved in bone formation.

CONCLUSION

Both surfaces were able to modulate bone responses toward osteoblast differentiation. SAE-HD presented a better response compared with SAE.

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.

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

OBJECTIVES

The aim of the present study was to explore the feasibility of ultrasonography (US) for clinical imaging of peri-implant tissues.

MATERIAL AND METHODS

Patients 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.

RESULTS

A 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.

CONCLUSION

US 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.

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.

Treatment efficacy of gingival recession defects associated with non-carious cervical lesions: a systematic review

Purpose

This systematic review aimed to compare the efficacy, defined in terms of the mean percentage of root coverage (mRC), of surgical treatment approaches combined with adhesive restorations of non-carious cervical lesions (NCCLs) to that of root coverage alone in patients with a single gingival recession (GR) and NCCL.

Methods

A literature search was conducted to identify longitudinal studies reporting the mRC following treatment for the correction of GR defects associated with NCCLs using a combination of surgical and restorative techniques in systemically and periodontally healthy patients.

Results

The search resulted in the retrieval of 12,409 records. Seven publications met the inclusion criteria for the qualitative synthesis of data. The mRCs ranged from 69% to 97%. In the medium term, the gingival margin position was more stable when a connective tissue graft (CTG) was used, independently of whether restoration of teeth with NCCLs was performed.

Conclusions

The strength of the evidence was limited by methodological heterogeneity in terms of study design as well as the unit and period of analysis, which precluded a meta-analysis. Although no definitive conclusion could be drawn due to the lack of sufficient evidence to estimate the effectiveness of the interventions, CTG-based procedures contributed to gingival margin stability regardless of the performance of restoration to treat NCCLs.

Hydrophilic titanium surface modulates early stages of osseointegration in osteoporosis

OBJECTIVE

Using a mouse osteoporotic model, this study aimed to determine the influence of hydrophilic titanium surfaces on gene expression and bone formation during the osseointegration process.

BACKGROUND

Based on the previous evidence, it is plausible to assume that osteoporotic bone has a different potential of bone healing. Therefore, implant surface modification study that aims at enhancing bone formation to further improve short- and long-term clinical outcomes in osteoporosis is necessary.

MATERIAL AND METHODS

Fifty female, 3-month-old mice were included in this study. Osteoporosis was induced by ovariectomy (OVX, test group) in 25 mice. The further 25 mice had ovaries exposed but not removed (SHAM, control group). Seven weeks following the ovariectomy procedures, one customized implant (0.7 × 8 mm) of each surface was placed in each femur for both groups. Implants had either a hydrophobic surface (SAE) or a hydrophilic treatment surface (SAE-HD). Calcium (Ca) and phosphorus (P) content was measured by energy-dispersive X-ray spectroscopy (EDS) after 7 days. The femurs were analyzed for bone-to-implant contact (BIC) and bone volume fraction (BV) by nano-computed tomography (nano-CT) after 14 and 28 days. Same specimens were further submitted to histological analysis. Additionally, after 3 and 7 days, implants were removed and cells were collected around the implant to access gene expression profile of key osteogenic (Runx2, Alp, Sp7, Bsp, Sost, Ocn) and inflammatory genes (IL-1β, IL-10, Tnf-α, and Nos2) by qRT-PCR assay. Statistical analysis was performed by ANOVA and paired t test with significance at P < .05.

RESULTS

The amount of Ca and P deposited on the surface due to the mineralization process was higher for SAE-HD compared to SAE on the intra-group analysis. Nano-CT and histology revealed more BV and BIC for SAE-HD in SHAM and OVX groups compared to SAE. Analysis in OVX group showed that most genes (ie, ALP, Runx2) involved in the bone morphogenetic protein (BMP) signaling were significantly activated in the hydrophilic treatment.

CONCLUSION

Both surfaces were able to modulate bone responses toward osteoblast differentiation. SAE-HD presented a faster response in terms of bone formation and osteogenic gene expression compared to SAE. Hydrophilic surface in situations of osteoporosis seems to provide additional benefits in the early stages of osseointegration.

Volumetric changes at implant sites: A systematic appraisal of traditional methods and optical scanning-based digital technologies

AIM

To evaluate techniques for assessing soft tissue alterations at implant sites and compare the traditionally utilized methods to the newer three-dimensional technologies emerging in the literature.

MATERIALS AND METHODS

A comprehensive search was performed to identify interventional studies reporting on volumetric changes at implant sites following different treatments.

RESULTS

Seventy-five articles were included the following: 30 used transgingival piercing alone, one utilized calliper, six with ultrasonography, six on cone-beam computed tomography, and 32 utilized optical scanning and digital technologies. Optical scanning-based digital technologies were the only approach that provided 'volumetric changes,' reported as volumetric variation in mm³ , or the mean distance between the surfaces/mean thickness of the reconstructed volume. High variability in the digital analysis and definition of the region of interest was observed. All the other methods reported volume variation as linear dimensional changes at different apico-coronal levels. No studies compared volumetric changes with different approaches.

CONCLUSIONS

Despite the emergence of optical scanning-based digital technologies for evaluating volumetric changes, a high degree of variation exists in the executed workflow, which renders the comparison of study results not feasible. Establishment of universal guidelines could allow for volumetric comparisons among different studies and treatments.

Challenges and Decision Making for the Classification of Two Complex Periodontal Cases

FOCUSED CLINICAL QUESTION

What are the fundamental debates and questions related to the newly developed two-vector system for classification of periodontal diseases that have emerged as to how to accurately assign, stage, and grade periodontitis cases? The aim of the present manuscript is to demonstrate the essential thought processes that are needed in utilizing the new periodontitis classification system to diagnose two gray zone cases.

SUMMARY

Clinical case 1 includes an 83-year-old male diagnosed with periodontitis and classified as Stage III Generalized Grade B periodontitis, while clinical case 2, a 73-year-old male was classified as presenting Stage IV Generalized Grade B periodontitis. Although clinical and radiographic evaluations revealed similarities between the cases, the thought process that includes clinical judgment is described to guide a more accurate diagnosis following the guidelines of the new classification system.

CONCLUSION

The two cases demonstrated here offer an opportunity for clinicians to recognize the essential role of sound clinical judgment in certain cases when applying the new periodontal disease classification system and also clarify questions emerging from implementing this classification system.

Does a fully digital workflow improve the accuracy of computer-assisted implant surgery in partially edentulous patients? A systematic review of clinical trials

BACKGROUND

Accurate implant placement is essential in reducing post-treatment complications and in ensuring a successful treatment outcome.

PURPOSE

To compare the accuracy of fully-guided static computer-assisted implant surgery (s-CAIS) using partially- and fully-digital workflows.

MATERIALS AND METHODS

Electronic and manual literature searches were performed to collect evidence concerning the accuracy of fully-guided s-CAIS procedures utilizing tooth-supported guides. Quantitative analysis was conducted to evaluate the accuracy of partially- and fully-digital workflows, and survival rates and complications were qualitatively analyzed.

RESULTS

Thirteen studies, including 6 randomized controlled trials and 7 prospective clinical studies, were selected for quantitative and qualitative synthesis. A total of 669 implants in 325 patients using s-CAIS were available for review. Meta-analysis of the accuracy revealed a total mean angular deviation of 2.68° (95% CI: 2.32°-3.03°); mean global coronal deviation of 1.03 mm (95% CI: 0.88-1.18 mm); mean global apical deviation of 1.33 mm (95% CI: 1.17-1.50 mm); and mean depth deviation of 0.59 mm (95% CI: 0.46-0.70 mm). Minimal differences were found between the two different workflows. Few complications were reported, and survival rates were between 97.8% to 100% (range of follow-up: 12 to 24 months) in the available studies.

CONCLUSION

Similar accuracy is obtained when implants are placed in partially edentulous patients using fully-guided s-CAIS, independently of the workflow utilized.

Lack of Clinical Benefit of Implantoplasty to Improve Implant Survival Rate

The objective of this study was to compare postsurgical outcomes of resective treatment for peri-implantitis with and without implant surface modification (implantoplasty [IP]). This was accomplished by a retrospective analysis with data from patients with ≥1 implant who were surgically treated for peri-implantitis by resective therapy. Patients were divided into 2 groups regarding treatment approach: IP (test) and no IP (control). Retrospective data were obtained after implant placement (T0) and the day of peri-implantitis surgical treatment (T1). Patients were then recalled (≥1 y after T1) for clinical and radiographic examination (T2). The findings were conclusive. A total of 41 patients (68 implants; mean ± SD follow-up, 41.6 ± 24.4 mo) were included in this study. The survival rate at the implant level was 90% in the test group and 81.6% in the control group ( P > 0.05). Multilevel regression analysis showed that the probability of implant failure was influenced by marginal bone loss (MBL) at T1 and not surgical modality. For example, peri-implantitis defects ≥50% and 25% to 50% MBL were 18.6 and 8.86 times more likely to lose the implant, respectively, when compared with <25% MBL. Nonetheless, MBL changes were similar in the test and control groups ( P = 0.592). Similarly, changes in bleeding on probing, probing pocket depth, and suppuration at T2 did not differ between groups ( P > 0.05). Multilevel regression analysis indicated that clinical improvement of these parameters was influenced by the number of supportive peri-implant therapy visits ( P < 0.01). The results demonstrate little difference between the procedures. Regardless of the implant surface modification (IP) being performed or not, the survival rate of implants treated for peri-implantitis was primarily influenced by the amount of bone loss at the time of treatment. Other clinical parameters (MBL, probing pocket depth, bleeding on probing, suppuration) were influenced by the frequency of supportive peri-implant therapy visits and not by the IP procedure (ClinicalTrials.gov NCT04259840).

Quantitative tooth mobility evaluation based on intraoral scanner measurements

BACKGROUND

Tooth mobility assessment is subjective and current techniques require the translation of a continuous variable to a categorical variable based on the perception of the examiner. The aim of this study was to evaluate the reliability of a novel technique to assess tooth mobility.

METHODS

Three experienced periodontists were asked to push tooth #16 into a buccal position to in a typodont model with different mobility (M1-M2). Tooth position was obtained using an intraoral scanner and files were compared in metrology software. Mobility was calculated at three reference points at the cervical (C), middle (M), and occlusal (O) regions of the buccal surface of the tooth to determine the linear deviation in the three axes (x, y, and z). Reliability was determined by intraclass-correlation coefficient, differences between M1 and M2 determined by t test, and the analysis of variance (ANOVA) was used to compare the data at the C-M-O regions.

RESULTS

Excellent reliability was assessed by Cronbach alpha >0.9 on the x-y-z axes for both mobility tested, except for M1-C X (0.85), M1-M Y (0.89), and M2-M Z (0.89). The correlation between the examiners demonstrated excellent (˃0.90) or good (0.75˃ x ˂0.90) consistency, except for M1-C Y (0.73; examiner 1 to 2) and M1-M X (0.69; examiners 1 to 3). Significant changes were detected in all axes at the three reference points comparing M1 and M2, and a similar proportional change was observed between O-M-C reference points for M1 and M2.

CONCLUSION

A novel technique to assess tooth mobility based on intraoral scanner measurements provided reliable data in an in vitro experiment.

Outcomes of root resection therapy up to 16.8 years: A retrospective study in an academic setting

BACKGROUND

Root resection has been considered a viable treatment option for molars with furcation defects. However, need of a multidisciplinary approach could potentially deem this procedure less successful. The aim of the present article was to determine survival rates of root resection procedure and reasons for failure in an academic setting.

METHODS

Patient-related demographic data, medical history information, and relevant data pertaining to the root-resected teeth performed from January 1990 to September 2017 were reviewed through electronic and paper chart. Survival rates were analyzed using Kaplan-Meier estimate. Association between the reasons for failure and independent variables was established by a Pearson Chi-squared and Kruskal-Wallis test.

RESULTS

A total of 85 patients with an average follow-up of 5 ± 4.3 years (range: 1 to 16.8 years) were included in the present article. A total of 47 molar teeth treated with root resection remained as part of the dentition (55.3%) and 38 (44.7%) failed. The mean survival time with the Kaplan-Mayer analysis was 109.9 months (9.1 years). Fracture (39.5%), caries (26.3%), and periodontal disease (23.7%) were the most common causes for failure. Interestingly, the majority of failures occurred in the first 4 years after therapy (n = 31; 81.5% of all failures).

CONCLUSIONS

Root resection therapy remains a treatment solution for molars with furcation defects. In an academic setting, >50% of teeth remained functional after 9 years of root resection therapy.

Metabolic surgery for the treatment of type 2 diabetes in pancreas after kidney transplant candidates

Metabolic surgery for the treatment of type 2 diabetes mellitus (T2DM) in patients not morbidly obese (BMI <35) has been widely studied. Taking into account that ∼12% of pancreas transplants are performed in patients with T2DM, our goal was to evaluate the impact of metabolic surgery on the management of obese patients with T2DM on waiting lists for a pancreas transplant. We performed a Roux-en-Y gastrointestinal bypass in 5 patients with insulin-dependent T2DM who were candidates for pancreas after kidney transplant and with a BMI <35. Three patients became insulin independent by the end of the first year while the other 2 reduced their insulin requirements by 70%. Furthermore, all patients achieved improved control of lipid levels. We concluded that the surgery was effective in controlling blood glucose and lipid metabolism in these obese T2DM kidney transplant recipients. In this population, a pancreas transplant, along with its associated morbidity, may be avoided.

Resection of a mediastinal schwannoma using video-assisted thoracoscopy

Schwannomas are tumors that are typically benign. They are derived from Schwann cells (glial cells of the peripheral nervous system that serve to separate and isolate nerve cells from adjacent structures). The most common type of schwannoma is a benign tumor of cranial nerve VIII and is referred to as an acoustic neuroma. When extradural, such tumors usually present as masses that can invade adjacent structures, thereby becoming symptomatic, as in the case of intrathoracic schwannomas (typically found in the posterior mediastinum). Herein, we present a case of a schwannoma treated through video-assisted thoracoscopy, and we review the literature on the subject.

An assay for the measurement of the protein content of cells immobilized in carrageenan

A reliable and reproducible method for the estimation of the protein content of fungal cells immobilized in a carrageenan gel is described. The procedure depends upon the acid lability of the polysaccharide gel at 90 degrees C and on the acetone solubility of accumulated phenolics. Freeze-dried gel beads (2-3 mm) containing entrapped cells of Penicillium urticae were ground to a fine powder and samples of powder (approximately 20 mg) were sequentially extracted with hot 1 N HCl - 0.9% NaCl and acetone. The precipitated residue contained the cell protein, which was then solubilized with 1 N NaOH at 90 degrees C and quantitated by the Folin-Lowry method. Interferences from both carrageenan and phenols were thus eliminated. The presence of carrageenan (20-25 mg) did not affect the recovery of varying amounts (0-2500 micrograms) of bovine serum albumin. The recovery of radiolabeled protein from immobilized cells was parallel to that of Folin-Lowry positive material over a range of 0-60 beads (0-60 mg powder). Cycloheximide (0-100 micrograms/mL) was shown to progressively inhibit the incorporation of L-[U-14C]leucine so that the radioactivity present in the initial HCl-NaCl extract (i.e., [14C]leucine) increased as that in the final NaOH extract (i.e., 14C-labeled protein) decreased. Using this new assay for cell protein, free and immobilized cell cultures were found to exhibit virtually identical kinetics of glucose utilization, growth, and patulin production. In addition to providing a means of comparing the specific productivity of free versus immobilized cell preparations, this assay accurately measures the incorporation of [14C]leucine into cellular protein and could be used as a measure of cell viability.