Excess Cement Research Articles

Polytetrafluoroethylene relative isolation for adhesive cementation of dental restorations

Tooth isolation is essential to isolate a prepared tooth from saliva, oral humidity, and gingival fluids and facilitate the removal of excess subgingival cement in adhesive cementation procedures. However, the isolation of prepared teeth can be challenging, especially with vertical preparations. A technique for achieving relative isolation by using polytetrafluoroethylene tape is described for adhesive cementation with vertical tooth preparations.

COMPARISON OF CEMENT AND SCREW FIXATION OF ORTHOPEDIC STRUCTURES

In dental prosthetics, every detail is important, because at this stage, not the aesthetic component is put in the first place, but the issue of engraftment of the implant. This will affect the further quality of life and the condition of the patient’s oral cavity. Therefore, in professional circles there are still discussions about which method of fixing the prosthesis is better - cementing or screw fixation, especially since both of them are widely used in dental surgery. This article will discuss the disadvantages and advantages of these methods.
 The connection of the implant, abutment and crown can be performed in two ways: fixation on cement - an abutment is fixed on the installed implant with a screw, on which the crown and dental cement are fixed. Screw fixation - the crown is connected to the abutment in advance, in the laboratory, then the finished structure is attached to the implant. For connection, a screw is used, which is inserted into a vertical hole penetrating the crown and abutment. After installing and fixing the crown, a hole remains on the chewing surface (the so-called screw shaft) - it is covered with a composite material.
 Of course, the screw design is mainly preferable due to the absence of excess cement. Excess cement is a good basis for biofilm formation. The larger the area of ​​the cement joint, the more bacteria appear. But the doctor is not able to use screw fixation in such situations: inconvenient entry into the implant shaft and there is no straight-line entry of the structure.
 Screw fixation has other advantages and disadvantages. The following advantages are distinguished: the crown can be easily removed; construction details fit exactly; there is no danger of cement getting into soft tissues; less work in the clinic and laboratory.
 So, when installing a denture, the orthopedist has two options for connecting the main parts of the structure (implant, abutment and crown) - cementing and screw fixation. In the first case, an abutment is fixed on the implant, and a cement-fixed crown is placed on top. During fixation, the screw crown is connected to the abutment in advance, and then the finished structure is attached to the implant itself. The method gets its name from a screw that is inserted into the crown and abutment and leaves a small hole in the crown. This "screw shaft" used to be a serious aesthetic problem, but now it is easily masked by the composite material.

Moving from analogue to digital workflows in dentistry: Understanding undermilling and overmilling as detrimental factors in fabricating CAD/CAM crowns.

Due to the limitations caused by the specific dimensions of milling burs, milling machines may inaccurately fabricate restorations by either over-reducing or under-reducing restorative material, respectively known as "overmilling" and "undermilling". Overmilling occurs when the bur is unable to accommodate areas smaller than the size of the bur, especially at cusp tips and sharp line angles. This results in excess cement space and a weaker restoration. Undermilling occurs when small concavities are ignored by the larger milling bur, particularly at the margins. This results in inadequate seating of the restoration and open margins due to premature binding, which can lead to restorative failure. To prevent these processing errors, clinicians should ensure that all incisal edges and cusp tips are flattened and rounded, verify that there are no undercuts, and prepare teeth with 1mm thick, smooth finish lines. Furthermore, clinicians may use the preparation check and milling simulation step of computer-aided design/computer-aided manufacturing (CAD/CAM) software to confirm the preparation is adequate and the restorative design does not have potential areas that will lead to overmilling.

Selection of 1-mm venting or 2.5-mm screw access holes on implant crowns based on cement extrusion and retention capacity

BackgroundThis in vitro study aimed to provide evidence regarding the selection of hole diameters of implant crowns to reduce excess cement extrusion at the abutment margin, and to examine the maintenance of their retention capacity in anterior and posterior cement-retained implant crowns.MethodsSix groups of implant crowns were prepared according to the position of the teeth and the size of their holes as follows: anterior crown without hole (ANH), anterior crown with 1-mm mini venting hole (AMH), anterior crown with 2.5-mm regular screw access hole (ARH), posterior crown without hole (PNH), posterior crown with 1-mm mini venting hole (PMH), and posterior crown with 2.5-mm regular screw access hole (PRH). Temporary cement was used to bond the crowns to the abutments. The mean amount of excess cement extrusion among the different groups at the abutment margin was calculated. Retentive strength under different hole designs was measured as the dislocation force of the crown using a universal testing machine. One-way ANOVA and Welch’s t-test were used to analyze the results.ResultsThe average amounts of extruded excess cement were 18.96 ± 0.64, 1.78 ± 0.41, and 1.30 ± 0.41 mg in the ANH, AMH, and ARH groups, respectively, and 14.87 ± 0.36, 1.51 ± 0.40, and 0.82 ± 0.22 mg in the PNH, PMH, and PRH groups, respectively. The hole opening in the crowns could significantly reduce residual cement regardless of its size (p < 0.001). The mean retentive strengths were 54.16 ± 6.00, 47.63 ± 13.54, and 31.99 ± 7.75 N in the ANH, AMH, and ARH groups, respectively, and 57.84 ± 10.19, 53.22 ± 6.98, and 39.48 ± 5.12 N in the PNH, PMH, and PRH groups, respectively. The retention capacity of the implant crown deteriorated rapidly as the holes on the crown surface enlarged.ConclusionsThe presence of a hole on the implant crown reduced the amount of excess cement. The retention ability of the implant crowns deteriorated as the size of the hole increased. Considering the esthetic effect of the crown and the possible influence on crown retention, an implant crown with a 1-mm mini venting hole is a better clinical choice than the one with a 2.5-mm regular screw access hole.

A technique to avoid the entrapment of excess residual luting cement in soft-tissue irregularities underneath fixed dental prostheses by using polytetrafluoroethylene tape

Excess residual luting cement must be removed meticulously to avoid postoperative complications.1-3 Various methods have been used to accomplish the removal of excess residual luting cement from interdental areas when cementing a fixed partial denture (FPD), including the use of dental floss, interproximal brushes, and nylon ligatures.4-6 However, preventing the entrapment of residual cement underneath the pontic area is challenging, especially in recent extraction sites and hard- and soft-tissue irregularities.

The Influence of Cement Removal Techniques on In Situ Bacterial Adhesion and Biodegradation at the Marginal Interface of Ceramic Laminates.

This in situ study aimed to analyze the influence of different resin cement removal techniques on bacterial adhesion and biodegradation at the marginal interface of ceramic laminates. Eighty feldspathic ceramic (F) blocks were prepared and cemented onto bovine enamel slabs (7×2.5×2 mm). Excess cement was removed using a microbrush (MBR), a scalpel blade (SCP), or a Teflon spatula (TSP). For the biodegradation analysis, 40 disc-shaped resin cement specimens were prepared (7×1.5 mm) using a Teflon mold. The specimens were randomly allocated into two groups: (1) No finishing procedure (only Mylar strip), and (2) with finishing and polishing procedures using the Jiffy system (Ultradent, South Jordan, UT, USA) (n=20). The in situ phase consisted of using an intraoral palatal device by 20 volunteers for 7 days. Each device contained five cylindrical wells (8×3 mm), where three dental blocks and two cement specimens were included in the wells. Surface roughness (Ra) was measured using a contact profilometer. A micromorphological analysis was performed under a stereomicroscope and a scanning electron microscope. Bacterial adhesion was quantitated based on the number of colony-forming units (CFU/mL) and their biofilm development potential. The cement removal techniques directly affected surface roughness at the marginal interface (p<0.001), and the SCP technique produced higher mean roughness, regardless of the surface area analyzed. Surface polishing protected cement specimens from further biodegradation (p=0.148). There were no differences in CFU counts between the groups after the in situ phase (p=0.96). All specimens showed CFU with a strong ability to develop a biofilm. The techniques used for cement removal increased the surface roughness of ceramic laminates, particularly SCP, but they did not affect bacterial adhesion at the marginal interface. Surface polishing of the resin cement is recommended to mitigate biodegradation.

A Systematic Review of Cementation Techniques to Minimize Cement Excess in Cement-Retained Implant Restorations.

Background: The most used types of retention of implant-supported prostheses are screw-retained or cement-retained restorations. The advantages and disadvantages of both have been identified by various authors over the years. However, cement-retained implant crowns and fixed partial dentures are among the most used types of restorations in implant prostheses, due to their aesthetic and clinical advantages. When cemented prostheses are made on implants, the problem of cement residues is important and often associated with biological implant pathologies. The objective of this research was to establish to what extent the techniques to reduce excess cement really affect the volume of cement residues. Materials and Methods: This review was written following the PRISMA statement; a detailed search was carried out in three different electronic databases—PubMed, Scopus, and Cochrane Library. The inclusion criteria were prospective clinical studies, with at least 10 participants per group, and with at least 6 months of the follow-up period. Results: There have been many proposals for techniques supposed to reduce the amount of excess cement in the peri-implant sulcus and on the prosthetic components, but of these, which are exceptional in their in vitro capabilities, very few have been clinically validated, and this represents the real limitation and a great lack of knowledge regarding this topic. Three articles met the inclusion criteria, which were analyzed and compared, to obtain the information necessary for the purposes of the systematic review. Discussion: Extraoral cementation can reduce the excess cement, which, after a normal excess removal procedure, is, nevertheless, of such size that it does not affect the possibility of peri-implant pathologies developing. All these studies concluded that a small amount of cement residue is found in the gingival sulcus, and using eugenol-free oxide cements, the residues were only deposited on the metal surfaces, with a better peri-implant tissues health. Conclusion: Despite the limitations of this study, it was possible to carefully analyze these characteristics and obtain valuable suggestions for daily clinical practice. Resinous cements are considered, due to the free monomers present in them, toxic for the soft tissues. The provisional zinc-oxide cements, also eugenol-free, represent the ideal choice. The different grades of retentive forces provided by these cements do not seem to have clinical effects on the decementation of restorations.

Effect of abutment neck taper and cement types on the amount of remnant cement in cement-retained implant restorations: an in vitro study.

PURPOSEThe present study aims to analyze the effect of abutment neck taper and types of cement on the amount of undetected remnant cement of cement-retained implant prostheses.MATERIALS AND METHODSThree neck taper angles (53°, 65°, 77°) and three types of cement (RMGI: resin-modified glass ionomer, ZPC: zinc phosphate cement, ZOE: zinc oxide eugenol cement) were used. For each group, the surface percentage was measured using digital image and graphic editing software. The weight of before and after removing remnant cement from the abutment-crown assembly was measured using an electronic scale. Two-way ANOVA and Duncan & Scheffe’s test were used to compare the calculated surface percentage and weight of remnant cement (α = .05).RESULTSThere were significant differences in remnant cement surface percentage and weight according to neck taper angles (P < .05). However, there were no significant differences in remnant cement surface percentage and weight on types of cement. No interaction was found between neck taper angles and types of luting cement (P > .05). The wide abutment with a small neck taper angle showed the most significant amount of remnant cement. And the types of luting cement did not influence the amount of residual cement.CONCLUSIONTo remove excess cement better, the emergence profile of the crown should be straight to the neck taper of the abutment in cement-retained implant restoration.

Evaluation of common cementing practices affecting primary cementing quality

The quality of cement placement in primary cementing depends on many facets of the cementing procedure. In this paper, we simulate the fluid displacement process of a typical horizontal well in Northern British Columbia. We analyze how variations in some of the common cementing practices may improve the displacement efficiency. By using excess cement volume, the residual mud can be gradually removed as long as there is a sufficient pressure gradient to yield the mud. Increasing the centralizer usage is demonstrably effective in removing residual mud in the deviated section, and the eccentricity is significantly improved. Performing staged cement allows improvement in displacement by allowing flexibility in frictional pressure loss management (often crucial in long horizontal wells). Targeting different strategies for vertical and deviated sections results in improved efficiencies. • Excess cement volume leads to better displacement efficiency. • Poor cementing quality identified through combination of CBL and simulation. • Increased centralization works, as we know! • Staged cementing allows reduced frictional pressures and focus on vertical and deviated sections separately. • Increased density difference in the vertical is effective; slow flow and slumping improves the horizontal.

The effect of social capital on innovation through the mediation of ambidexterity and knowledge sharing in cement industry

&lt;em&gt;Indonesia's economy is in a precarious state, made worse by the presence of the corona virus disease 2019 (Covid-19) pandemic. As a result, it is critical for businesses to be able to adapt to changes in an uncertain business environment. One option for the business to endure is through innovation. Previous study has established that social capital, the ability of the work team to be ambidextrous and knowledge sharing play a critical role in the creation of innovation inside the organization. The purpose of this study is to examine the effect of social capital on innovation through the mediation of ambidexterity and knowledge sharing in work teams at PT Indocement Tunggal Prakarsa Tbk, one of the largest private cement companies in Indonesia. The company operates in an unstable environment due to the global crisis, politics, price competition, and excess cement production capacity in Indonesia since 2016. This research is quantitative research with purposive sampling method using Structural Equation Modeling (SEM) analysis with Partial Least Square (PLS) method to test the hypothesis. The study's findings demonstrate that social capital can influence the generation of innovation when it is mediated through ambidexterity and knowledge sharing. This research is expected to assist enterprises in the Indonesian cement sector in surviving by fostering innovation within each work team.&lt;/em&gt;

Evaluation of the marginal excess cement and retention force of implant-supported zirconia crowns with various vent designs under different cement application patterns.

To investigate the effects of implant-supported zirconia crowns with various vent designs on the marginal excess cement (MEC) and retention values under different cement application patterns. Cercon zirconia crowns (n=36) were divided into the following groups: no venting (NV group), a small occlusal vent hole (SOV group), a large occlusal vent hole (LOV group), and a small palatal-occlusal vent hole (SPV group). The cement was applied to the crowns with different methods: occlusally half axial walls (OH), cervically half axial walls (CH) and all axial walls (AA), and different amounts of cement were applied with a chosen method. The weight of the MEC was calculated, and the retention force was recorded. ANOVA was used to analyze the MEC weights and retention values. In all vented groups, the OH application method resulted in no MEC and the least retention force, and the AA method expressed significantly less MEC (p < 0.01) than the CH method without retention force reduction. At each amount of cement (5, 10, 20, 30 mg), all three venting designs significantly reduced the MEC by the AA method, and the mean MEC of the LOV group was lower than that of any other group. Applying a thin layer of cement evenly to all axial walls of vented zirconia crowns showed excellent clinical effects regarding the MEC and the retention force. Residual excess cement was identified as a possible risk indicator for peri-implant diseases. Simply and effectively minimizing marginal extrusions without reducing the retention force has clinical value. The results of this study indicate that applying a thin layer of cement evenly to all axial walls of vented zirconia crowns is an acceptable method.

Endocrowns Clinical Performance and Patient Satisfaction: A Randomized Clinical Trial of Three Monolithic Ceramic Restorations.

The purpose of this randomized, double-blind, clinical trial was to assess the survival of endocrowns made from three different monolithic ceramic materials, and to evaluate patient satisfaction. Fifty-three patients (sixty root canal treated molar teeth) were enrolled. Teeth were prepared to a flat butt-joint margin and randomly divided between three material groups: lithium disilicate-reinforced glass-ceramic, monolithic zirconia and polymer infiltrated hybrid ceramic. Predefined cementation protocols were used. Clinical assessment using modified United States Public Health Service (USPHS) criteria was carried out after two years by two independent clinicians blinded to the material used. Radiographic examination was conducted to check for the presence of caries, excess cement, and periapical infection. Statistical analysis was performed using the Kruskal Wallis and Wilcoxon signed-rank tests as well as the Kaplan-Meier survival estimate. Forty-eight patients were available for assessment after 2 years (recall rate 90.6%). The overall Kaplan-Meier survival estimate among all groups was 90.9% with no statistically significant difference between the groups (p = 0.17). Three zirconia endocrowns debonded after 9, 10 and 13 months (82.4% survival rate), while 2 hybrid ceramic endocrowns chipped/fractured (89.5% survival rate). Lithium disilicate endocrowns had a 100% survival rate. The Kruskal Wallis test revealed no statistically significant difference between the groups in the USPHS criteria ratings and the radiographic assessment (P>0.05). Patient satisfaction ranged from 82.3% in the zirconia group to 100% in both the lithium disilicate and hybrid ceramic groups. Endocrowns provide a predictable option for the restoration of endodontically treated molar teeth in the short term. Lithium disilicate-reinforced ceramic had fewer complications and required less intervention compared with zirconia and hybrid ceramics. Long-term follow-up is required to substantiate these study results.

Clinical, radiographic, and immunological evaluation of angulated screw-retained and cemented single-implant crowns in the esthetic region: A 1-year randomized controlled clinical trial.

Screw-retained implant crowns are considered more biologically compatible than cemented crowns due to the absence of excess cement. However, traditional screw-retained implant crowns are not viable when the access hole of the screw channel would need to be located in an esthetic area, which would compromise the esthetic outcome of the treatment. To evaluate the clinical, radiographic, and immunological outcomes of angulated screw-retained and cemented single-implant crowns in the esthetic region. The study was a single-center, open-label, randomized controlled clinical trial. Eligible patients were randomly placed in two groups: angulated screw-retained group (AG) and cemented group (CG). Implant survival rate, bleeding on probing rate (BOP%), probing depth (PD), modified plaque index (mPI), marginal bone loss (MBL), concentrations of pro-inflammatory cytokines (TNF-α, IL-6) in peri-implant crevicular fluid (PICF), mechanical complications, and pink esthetic score/white esthetic score (PES/WES) were evaluated. Fifty-six patients (AG: 29, CG: 27) attended the 1-year examination. The drop-out rate was 6.67%. No implant failure was found in both groups during the observation period. BOP% was significantly lower in the AG than that in the CG (mean, 21.84% ± 19.97% vs. 37.04% ± 26.28%, p=0.018). The concentration of TNF-α in PICF was significantly higher in the AG than that in the CG (median, 13.54 vs. 4.62, p=0.019). No significant difference of PD, mPI, MBL, IL-6, or mechanical complication rates was found between the two groups. Mean scores for PES/WES were 21.71 and 21.64 in the AG and CG, respectively. Based on the present results, both treatment options showed acceptable clinical outcomes in the short term. Angulated screw-retained crowns might benefit the peri-implant soft tissue. However, studies with long-term follow-up are needed to confirm whether the higher concentration of TNF-α will compromise the long-term outcomes of treatment.

Microcomputed tomography void analysis after cement cleanup methods

Statement of problemCement at the restorative margin after implementation of the manufacturer’s recommended procedure for cement cleanup has not been extensively evaluated. PurposeThe purpose of this in vitro study was to use microcomputed tomography (μCT) to evaluate the number, volume, and width of voids left at the margin when dental cement is cleaned during the cementation process as per 2 manufacturer-prescribed methods for cement cleanup by evaluating a self-adhesive resin cement and a resin-modified glass ionomer cement. Material and methodsTwenty molar Ivorine Typodont prepared teeth were scanned, and lithium disilicate crowns were milled and cemented to the prepared teeth as per the manufacturer-recommended cementation process. Two methods of cement cleanup were performed: the excess cement was tack-polymerized with a polymerization light, or a delay of 3 minutes was used for the excess cement to reach partial polymerization, and the excess cement was removed with a sharp sickle scaler. These 2 methods of cement cleanup were performed with 2 cements: a resin-modified glass ionomer cement and a self-adhesive resin. Each specimen was then scanned with a μCT machine. The buccal margin of each specimen, from mesiobuccal line angle to distobuccal line angle, was examined, and the number, volume, and width of any voids remaining at the margin open to the environment were measured. For statistical analysis, the specimens were first grouped by method of cement cleanup and then grouped by cement type. The Wilcoxon ranked sum test was implemented because of the lack of a normal distribution and the heterogeneity of the data (α=.05). ResultsNo statistically significant difference was found in the median number of voids, median volume of voids, or median width per void between the 2 cleanup methods, irrespective of cement type (P>.05). Significant differences were found in the median number of voids, median volume of voids, and median width per void when comparing cement types, irrespective of cement cleanup methods (P<.05). ConclusionsThe choice of cement may be more important than the method of cement cleanup when considering voids left at the margin. Microcomputed tomography is an excellent nondestructive tool for volumetric measurements of voids at the margin.

Predictable 3D guided adhesive bonding of porcelain veneers using 3D printed trays.

This clinical report describes a novel digital technique to facilitate and improve the porcelain laminate veneers adhesive bonding procedure using a customized 3D printed guide. Porcelain veneers can be stabilized in their fully seated position with a digitally design 3D printed guide before the resin cement is polymerized. The excess cement can be carefully and predictably removed without the risk of dislodgement, rotation or misfit, allowing the clinician to light cure them under controlled pressure in the correct seating position without the risk of fracturing the ceramic material. Fabricating a custom 3D printed guide for veneer bonding provides significant assistance to an otherwise cumbersome and daunting clinical procedure. Adhesive bonding of multiple ceramic veneers is a challenging and technique sensitive procedure. The use of a custom 3D printed guide presented in this article offers a practical aid to achieve a more predictable and precise outcome.

Influence of collar height of definitive restoration and type of luting cement on the amount of residual cement in implant restorations: A clinical study

Statement of problemResidual cement in the peri-implant sulcus may cause peri-implant mucositis, which can lead to peri-implantitis. Clinical studies comparing the role of the collar height of the definitive restoration and the type of cement used for luting the prosthesis in the amount of residual cement are lacking. PurposeThe purpose of this clinical study was to determine the volume of residual cement left undetected in the peri-implant sulcus by an implant prosthesis with 3 different collar heights and 3 luting cements. Material and methodsParticipants with single implants in the premolar region were divided into 3 groups of 10 according to the distance from the peri-implant soft tissue crest to the implant platform: group low collar (sulcus depth <2 mm), group medium collar (2-4 mm), and group high collar (>4 mm). A metal-ceramic crown with an occlusal opening was fabricated on a straight titanium abutment, which facilitated removal of the crown along with the abutment after cementation. The implant luting cements used were composite resin cement (RelyX U200), Type I glass ionomer cement (GC Gold Label 1), and zinc oxide noneugenol interim luting cement (RelyX Temp NE). The modified crown was cemented with 1 cement each during the impression, bisque evaluation, and definitive crown cementation appointments. The crown was retrieved, and the residual cement collected during each appointment. The measurements obtained were statistically analyzed with general linear model analysis followed by post hoc testing using the Bonferroni test (α=.05). ResultsMean volume of the residual excess cement (mm3) formed in group low collar was 0.33 ±0.17, 0.26 ±0.17, and 0.08 ±0.08 for subgroups Resin, GIC, and ZNE, respectively. In group medium collar, it was 1.18 ±0.31, 1.08 ±0.3, and 0.61 ±0.32; and in group high collar, it was 2.33 ±0.31, 2.1 ±0.74, and 1.31 ±0.56 for the same subgroup, respectively. There was a statistically significant difference in the formation of REC between the collar height groups (P<.001). Among the luting cements, zinc oxide noneugenol cement produced significantly lower residual cement compared with the other 2 cements, and there was no statistically significant difference between the glass ionomer and resin cements (P>.05). ConclusionsThe collar height of the definitive restoration and the type of luting cement play significant roles in the formation of residual cement in fixed implant-supported restorations.

Effect of different geometric changes in the dental implant abutment body on the amount of residual excess cement and retention in a cemented implant-supported prosthesis.

Fixed implant-supported restorations are mainly used in dental implantology. In comparison with screw-retained implants, cement-retained prostheses have the following advantages: the ease of splinting implants; increased passive casting; and procedural similarity to conventional tooth-supported fixed partial dentures. Furthermore, they show reduced fracturing of components with better esthetic outcomes and an improved force direction, along with a reduced cost and less chairside time. The aim of this study was to evaluate the effect of different geometric changes in the dental implant abutment body on the amount of residual excess cement (REC) and the retention of cemented implant-supported prostheses. Seventy-two straight abutments were categorized into 4 groups: vertical groove; 1 horizontal groove; 2 horizontal grooves; and ccontrol (with no geometric changes in the abutment). The access hole was partially filled and the cast copings were cemented using Temp-Bond™ NE, a non-eugenol cement. The difference in weight before and after removing the excess cement was considered as REC. Furthermore, the retention of the cast coping was measured as the force that was required to separate the cemented cast coping from the abutment. The mean REC values of the groups with 1 and 2 horizontal grooves were significantly different as compared to the control group (p < 0.05). This study shows that the presence of 1 or 2 horizontal grooves in the abutment body significantly reduces the amount of REC in comparison with control.

Current Concepts on the Pathogenesis of Peri-implantitis: A Narrative Review.

As implant treatment has been integrated in contemporary dental practice, complications with the forms of peri-implant mucositis and peri-implantitis have also increased in prevalence. Peri-implantitis is the more severe biological complication and is defined as an inflammatory disease affecting peri-implant tissues resulting in bone and eventually implant loss. In addition, the treatment of peri-implantitis has currently become a substantial global economic burden. In the current study, a search was conducted in several electronic databases using specific keywords relevant to the article’s main topic. An increasing number of scientific reports have investigated the etiopathology of peri-implant diseases, focusing mainly on peri-implantitis. Microbial biofilm consists an important etiological factor of peri-implant pathology analogous to periodontal diseases. Although several data confirm that peri-implant infections are dominated by gram-negative bacteria, similar to periodontal infections, there is evidence that some cases may harbor a distinct microbiota, including opportunistic microorganisms and/or uncultivable species. Additionally, data support that several parameters, such as genetic predisposition of individual patients, occlusal overload, and local factors such as titanium particles and excess cement, may be implicated in peri-implantitis pathogenesis. Simultaneously, the release of titanium metal particles and their biological consequences or the presence of excess cement in the adjacent peri-implant tissues have also been suggested as factors that contribute to peri-implant pathology. A specific line of research also indicates the role of foreign body response to implant installation. This narrative review aims to discuss the current concepts of etiopathogenetic factors implicated in peri-implantitis.

Determination of Suitable KCl Polymer Mud Properties for POK Field

Most oil and gas wellbores are drilled using water based mud (WBM), but this is the case when drilling through non-reactive formations that does not contain swelling shale. In reactive shale formation, KCl Polymer additive should be added to the mud. It will provide a source of potassium ions which will help stabilizing the reactive shale. So that the swelling process is minimized. The basis of the KCL polymer mud system is the polymer used as a wrapper for rock pieces during borehole cleaning process. In the wells in the POK Field, the use of polymer KCL mud is evaluated on trajectories of 17½", 12¼", and 8½ ". The evaluation process uses parameters that aim to find the suitable mud properties that result in the best drilling performance in each trajectory in the POK Field well. The determination of the best drilling performance is based on drilling time. The parameters used in this research are: rate of penetration, trip time, yield point (YP), K+ content, mud weight (MW), viscosity (m), plastic viscosity (PV), and gel strength (GS), mud cake, pH, and additional parameter (excess cement). Based on analysis and investigation, the best drilling performance for trajectory of 17½" occured in POK 1075 well, while the best performance for the trajectories 12¼” and 8½” occured in POK 1058 well. Therefore the KCl polymer mud properties used in these wells can be used as a reference and basis for planning mud systems for the next wells.

Comparing effectiveness of rubber dam and gingival displacement cord with copy abutment in reducing residual cement in cement-retained implant crowns: A crossover RCT.

To evaluate the amount of residual cement after cementation of implant crown abutments with rubber dam and retraction cord with copy abutments techniques. Thirty single posterior metal-ceramic implant-supported restorations were delivered to 20 patients. The crowns were fabricated with occlusal openings obturated with composite, and then luted with resin-reinforced glass-ionomer cement on customised standard abutments. The cementation procedure was performed twice in the same specimens using rubber dam (group 1) and retraction cord with copy abutment (group 2). If no cement remnants were seen on periapical radiographs after cleaning, the crown-abutment unit was dismounted. All quadrants of the specimens were photographed to calculate the percentage proportions of residual cement area. Mann-Whitney and Kruskal-Wallis tests were used for statistical analysis. In each group, 120 measurements were performed (30 implants, 4 surfaces each). The median percentage ratio with interquartile range (IQR) between the cement remnant area and total specimen area was 1.39% (IQR 0.77%-2.29%) and 0.58% (IQR 0.31%-1.33%) in groups 1 and 2, respectively. Lesser cement remnants were found in group 2 with a statistically significant difference (p<.001). The comparison of the mesial, distal, buccal, and lingual surfaces in each group showed no statistically significant differences between them (group 1, p=.482; group 2, p=.330). The retraction cord and copy abutment reduced the excess cement more efficiently than the rubber dam did. Notwithstanding, undetected cement remnants were observed with both methods, and neither should be considered reliable in clinical applications.