Comparative Analysis of Postcementation Hypersensitivity with Glass Ionomer Cement and a Resin Cement: An in vivo Study

Aim: The aim of this clinical study was to compare the postoperative sensitivity of abutment teeth restored with full coverage restorations retained with either conventional glassionomer cement (GIC) or resin cement. Materials and methods: Fifty patients received full-coverage restorations on vital abutment teeth. Of these, 25 were cemented with GIC (GC Luting and Lining cement) and the other 25 using an adhesive resin cement (Smartcem 2). A randomized single blind study was undertaken for acquiring and evaluating the data. The teeth were examined before cementation, after cementation, 24 hours postcementation and 7 days postcementation. A visual analog scale was used to help the patient rate hypersensitivity. Results: The statistical analysis of the result was done using students paired t-test. No statistically significant difference between Smartcem 2 and GIC was observed, when tested immediately and 24 hours after cementation. Statistically significant difference was seen between Smartcem 2 and GIC when tested 7 days postcementation with a significance level of 0.05. Higher postoperative sensitivity was seen with GIC when compared to resin cement. Conclusion: In this study, the incidence of postoperative hypersensitivity after cementation of full-crown restorations with GIC and resin cement was similar when tested immediately. However, 7 days postcementation, abutments with GIC showed higher response compared to resin cement. Clinical significance: A self-adhesive resin cement can be the material of choice for luting if presence of postoperative sensitivity is of prime consideration. In case GIC is being used, patient should be informed about the presence of sensitivity for a more prolonged period than with resin cement. Keywords: Resin cement, Hypersensitivity, Visual analog scale, Full-coverage restoration. How to cite this article: Shetty RM, Bhat S, Mehta D, Srivatsa G, Shetty YB. Comparative Analysis of Postcementation Hypersensitivity with Glass Ionomer Cement and a Resin Cement: An in vivo Study. J Contemp Dent Pract 2012;13(3): 327-331. Source of support: Nil Conflict of interest: None declared.     

Short-term clinical evaluation of a resin-modified glass-ionomer luting cement.

OBJECTIVES: Resin-reinforced glass-ionomer cements were developed by adding resin components to conventional glass-ionomer cement. This improved physical properties and bonding characteristics. FujiCEM is the first paste-paste-type resin-modified glass-ionomer luting cement that enables consistent mixture. The purpose of this study was to evaluate the short-term clinical performance of FujiCEM, which was used for final cementation of indirect restorations, such as inlays, crowns, and fixed partial dentures. METHOD AND MATERIALS: A total of 290 restorations (165 crowns, 71 inlays, 15 onlays, 36 fixed partial dentures, 3 implant superstructures) were placed in 268 patients (137 males, 131 females) with a mean age of 54.4+/-13.0 years. Restorations were luted with FujiCEM mixed for 10 seconds after the teeth surfaces were treated with a conditioner containing 10% citric acid and 2% ferric chloride for 20 seconds, washed, and dried with gentle air flow. Out of the investigated 337 teeth, 99 (29%) teeth were vital, and 238 (71%) were nonvital. These restorations were followed up for a period of 21 months. All the restorations were evaluated for postoperative sensitivity, secondary caries, gingival condition, and pocket depth. RESULTS: No clinical failures (eg, dislodgment, secondary caries, irritation of soft tissue, and postoperative sensitivity) were observed. CONCLUSION: FujiCEM had promising clinical performance with inlays, crowns, onlays, fixed partial dentures, and implant superstructures at 21 months after service.     

即刻牙本质封闭对预备后牙本质敏感程度的影响

目的评价牙本质即刻封闭技术对牙体预备后活髓基牙牙本质敏感程度的影响。方法30例患者行后牙三单位固定义齿修复,每例口内有2颗活髓后牙参与实验,基牙随机分为实验组和对照组。实验组在基牙预备后行即刻牙本质封闭,随后取模。对照组在基牙预备后常规取模,不进行即刻牙本质封闭。1周后行最终修复,全冠粘接后1周、1个月、6个月、12个月和18个月时检查记录患者的牙本质敏感程度,并进行统计学分析。结果固定义齿粘接后1周及1个月,实验组出现敏感基牙数少于对照组（1周：Z=-1.88,P=0.03;1个月：Z=-2.15,P=0.02）。粘接后6、12及18个月两组敏感发生率间差异无统计学意义（6个月：Z=-0.69,P=0.30;12个月：Z=-0.41, P=0.69;18个月：Z=-0.42,P=0.52）。比较两组敏感程度结果显示,实验组敏感的基牙,敏感程度主要为1度;对照组主要为1度及2度。1周及1个月观察点两组疼痛程度差异有统计学意义（1周：P＜0.05,1个月P=0.027）。结论活髓基牙牙体预备后行即刻牙本质封闭,可有效降低术后短期内牙本质过敏的发生率,减小患者的术后不适感。     

Three-year clinical evaluation of a resin modified glass-ionomer cement and a composite resin in non-carious class V lesions

The purpose of this study was a 3-year clinical evaluation of a resin modified glass-ionomer and a composite resin restorative material in non-carious class V lesions. In 24 patients 98 non-carious class V lesions were restored with either a resin modified glass-ionomer (Vitremer), or a composite resin restoration (Z100). The restorations were clinically evaluated after 6, 12, 24 and 36 months with the US Public Health Service criteria. At 3 years, 88 teeth of 21 patients were evaluated. All restorations were rated clinically acceptable for colour match, marginal discoloration, marginal adaptation and anatomical form. Restoration retention of both groups was high without any statistically significant difference. However, Vitremer restorations showed a lower incidence of Alfa scores for colour match and marginal discoloration than Z100 restorations (P < 0.05).     

Longevity of extensive class II open-sandwich restorations with a resin-modified glass-ionomer cement.

Several new techniques have been introduced for use in the esthetic restoration of posterior cavities to substitute for the presumed toxicity of amalgam. Composite-laminated glass-ionomer cement restorations, the sandwich technique, have been recommended for caries-risk patients. Clinical evaluation of the use of conventional glass-ionomer cements in the open-sandwich restoration has shown a high failure rate. The aim of this study was to evaluate the durability and cariostatic effect of a modified open-sandwich restoration utilizing a resin-modified glass-ionomer cement (RMGIC) in large cavities. The materials consisted of 274 mostly extensive Class II Vitremer/Z100 restorations performed by four dentists in 168 adults. Six experimental groups were investigated. In four groups a thick and in two groups a thin layer of cement was placed. Cavity conditioning before application of the RMGIC self-etching primer was done in 3 groups with polyacrylic acid and in one group with maleic acid; in two groups, only water rinsing was performed. The restorations were evaluated at baseline and after 6, 12, 24, and 36 months according to modified USPHS criteria (van Dijken, 1986). After 3 years, 239 restorations were evaluated. Twelve (5%) were estimated as non-acceptable. Two were replaced, and seven were repaired with resin composite. Tooth fractures were observed in 2.5%. Slight erosion of the RMGIC part was seen in 4%, and in one case operative treatment was indicated. Post-operative sensitivity was reported for 9 teeth. Forty-three percent of the patients were considered as caries-risk patients. Only one restoration showed secondary caries. The three-year results indicated that the modified open-sandwich restoration is an appropriate alternative to amalgam including extensive restorations.     

Two-year clinical evaluation of four polyacid-modified resin composites and a resin-modified glass-ionomer cement in Class V lesions.

OBJECTIVE: The aim of the study was to compare the clinical performances of four polyacid-modified resin composites (F2000, Dyract AP, Compoglass F, and Elan) and one resin-modified glass-ionomer cement (Vitremer) in Class V abrasion/erosion lesions. METHOD AND MATERIALS: Twenty restorations of each of the five restorative materials were placed in noncarious cervical abrasion/erosion lesions by one dentist. No cavity preparation was attempted. All teeth were isolated with cotton rolls and gingival retraction cord. The materials were manipulated according to the manufacturer's instructions and placed with the help of cervical matrixes. Restorations were finished and polished immediately after the placement. Evaluations were performed at baseline and 6 months, 1 year, and 2 years after placement for retention, color match, cavo-surface marginal discoloration, anatomic form, marginal adaptation, secondary caries, and postoperative sensitivity. RESULTS: Retention levels at 2 years were 90% for F2000, 90% for Dyract AP, 89% for Compoglass F, 84% for Elan, and 95% for the Vitremer restorations. No statistically significant differences were found among the materials after 2 years for any evaluation category. CONCLUSION: Polyacid-modified resin composite and resin-modified glass-ionomer cement restorations showed acceptable clinical performance after 2 years.     

劲润牙本质保护膜防治牙体预备后牙本质敏感的近期疗效观察

目的评价劲润牙本质保护膜(Hybrid coat)对活髓基牙预备后牙本质敏感的防治效果。方法将54例(共115颗)进行固定桥修复行牙体预备的基牙,对缺牙区两侧基牙随机分组,试验组在牙体预备后表面用劲润牙本质保护膜处理,对照组牙体预备后不做任何处理,所有基牙均采用暂时冠修复,备牙后和10天试戴修复体时观察治疗效果,评定疗效,并对戴牙前评定的疗效进行统计学分析。结果经劲润牙本质保护膜处理过的基牙牙本质敏感症状明显改善,两次疗效比价,有效率差别有统计学意义(P<0.05)。结论劲润牙本质保护膜可以有效防治活髓基牙预备后的牙本质敏感症状,值得在临床上推广应用。     

Resin-bonded prostheses for posterior teeth.

This study evaluated fixed partial dentures bonded with resin to dentin on posterior teeth with minimal tooth preparation. The patients included were missing at least one premolar or first molar. The abutment teeth next to the modification spaces were moderately restored with MOD or class II restorations on most of the teeth. A total of 20 patients with 23 fixed partial dentures were included in the study. After removal of existing restorations, the abutment teeth were prepared to eliminate undercuts on the perimeter of the preparations. Undercut areas within the preparation were not filled but were blocked out later in the laboratory. The fixed partial dentures employed inlays as retainers for a metal ceramic pontic. The metal framework was cast in a high noble gold alloy. The areas of the retainers to be bonded were treated with the Kulzer Silicoater method. Immediately before cementation, enamel was etched and exposed dentin was treated with Gluma. Kerr's resin bonded bridge cement was used for cementation. Patients were recalled after periods of 1 week, 1 month, 6 months, 1 year, 2 years, and 4 years for evaluation. None of the restorations lost retention and no major adverse effects were observed in the 4-year follow-up period.     

Clinical evaluation of two adhesive composite cements for the suppression of dentinal cold sensitivity

STATEMENT OF PROBLEMS: Postoperative cold sensitivity after the cementation of indirect restorations with composite cements has been reported frequently but not scientifically documented. PURPOSE: This controlled clinical study was designed to simulate the dentin/composite cement interface immediately after cementation of a cast restoration. The desensitizing capabilities of a composite cement that contains a self-etching, dual-polymerizing resin adhesive system were compared with those of a composite cement that use phosphoric acid etching followed by a single-bottle, light-activated primer/resin-based adhesive. MATERIAL AND METHODS: The hypersensitive root surfaces of selected teeth were randomized to receive 1 of 3 treatments: coating with a self-etching adhesive (Linkmax) and its respective cement, coating with a conventionally etched adhesive (RelyX ARC) and its cement, or no treatment (negative control). The sample size was 22. Dentin sensitivity was ascertained with an accurate cold testing device that slowly decreased in temperature. Tooth sensitivity was measured both immediately and at 7 days after placement. Two-way analysis of variance and Fisher's least significant difference test (P<.05) were used to determine whether significant differences existed as a function of treatment type or time. RESULTS: Immediately after placement, the self-etching adhesive and its respective cement resulted in more suppression of cold sensitivity than no treatment (control); with Linkmax treatment, the temperature at which teeth responded was reduced by 8.4 degrees C. The conventionally etched adhesive and its cement reduced the temperature at which teeth responded by 9.4 degrees C. After 1 week, these temperature reductions were 7.0 degrees C and 4.3 degrees C, respectively. Untreated controls at the 2 intervals showed a mean decrease in sensitivity to cold of 3.6 degrees C and 4.1 degrees C. Statistical analysis showed type of composite cement to be a significant factor. CONCLUSION: Within the limitations of this study and in comparison to untreated control teeth, Linkmax treatment resulted in a significant reduction in tooth root sensitivity over 1 week (P=.02), whereas RelyX ARC did not (P=.066).     

Metal–ceramic crowns cemented with two luting agents: short-term results of a prospective clinical study

A prospective, randomized, controlled, split-mouth trial was performed to evaluate the cementation modes for metal-ceramic crowns. A total of 40 fully veneered metal-ceramic crowns were delivered in the posterior jaw segments of 20 patients using either a self-adhesive resin cement (RelyX Unicem Aplicap, 3M ESPE; n = 20) or a zinc oxide phosphate cement (Hoffmann's Cement, Hoffmann; n = 20). Thirteen parameters related to the abutment teeth and their periodontal status were evaluated. A visual analog scale was used to assess the sensitivity of the abutment teeth by patient-based outcomes. Data were statistically analyzed by a single-classification ANOVA (α = 0.05) and logistic regression analysis. The results presented were obtained after a mean observation period of 1.8 years. The dropout rate was 0%. None of the abutment teeth exhibited secondary caries at the restoration margins. No significant differences were demonstrated between the luting agents based on visual analog scale (p > 0.05), hypersensitivity (OR = 1.31), abutment mobility (p > 0.05), or probing depths (p > 0.05). Based on the sulcus fluid flow rates, a significantly greater mean difference was obtained with zinc oxide phosphate cement than with self-adhesive resin cement (9.2 units; p = 0.0006). Significant differences between the baseline examination and the follow-up examinations for sulcus bleeding index (p = 0.0013) and plaque index (p < 0.0001) were observed regardless of the luting agent used. The two cement types showed scarcely any differences between the parameters investigated. The outcomes of cementing fully veneered metal-ceramic crowns were equally good with self-adhesive resin cement as with the clinically proven zinc oxide phosphate cement.     

Clinical outcome of three-unit lithium-disilicate glass–ceramic fixed dental prostheses: Up to 8 years results

ObjectivesThe purpose of this prospective study was to evaluate the clinical outcome of crown-retained fixed dental prostheses (FDPs) made from a lithium-disilicate glass–ceramic (IPS e.max Press, Ivoclar-Vivadent).MethodsThirty-six three-unit FDPs were placed in 28 patients. The FDPs replaced teeth in the anterior (16%) and posterior (84%) regions. All teeth were prepared following a standardized protocol. The size of the proximal connector of the FDPs was 12 mm² (anterior) or 16 mm² (posterior). FDPs were cemented either with glass-ionomer cement (n = 19) or composite resin (n = 17). The following parameters were evaluated at baseline, 6 months after cementation and then annually (at abutment and contralateral teeth): probing pocket depth, plaque index, bleeding on probing, and tooth vitality.ResultsThree FDPs were defined as drop-out. The mean observation period of the remaining 33 FDPs was 86 months (range: 67–98 months): two FDPs in two patients had to be replaced (6%) because of fractures. The 8-year survival rate according to Kaplan–Meier was 93%. In addition, chipping of the veneering material was found in two FDPs (6%). Two abutments (3%) of two restorations had to be treated endodontically; and two FDPs (6%) lost retention and had to be recemented. These complications did not affect the function of the involved restorations clinically. There were no significant differences between the periodontal parameters of the test and control teeth.SignificanceShort-span crown-retained three-unit FDPs made from lithium-disilicate glass–ceramic can be used clinically irrespective of an adhesive or conventional cementation.     

Early bond strength of luting cements to a precious alloy.

Previous studies have reported that glass-ionomer and adhesive resin cements can bond to various alloys, while zinc phosphate cements lack this adhesive property. This study evaluated the bonding properties of three luting cements during the first seven days after cementation. Thirty cylinders were cast with a high-noble porcelain-fused-to-metal (PFM) alloy and luted in pairs with one of the cements. The joints were stored in water at 37 degrees C for one, two, or seven days before being fractured in shear. The cylinders were re-used to provide 40 joints within each test group. The data were subjected to a Weibull analysis, a curve-fitting method shown to be appropriate for comparing the bond strengths of dental materials. The results showed that the zinc phosphate cement was the weakest material, whereas the adhesive resin produced the strongest joints. Microscopic observations of the fractured samples did not reveal any specific differences between the samples in terms of their mechanism of fracture. The glass-ionomer cement reached its maximum bond strength after two days, whereas storage time had no influence on the zinc phosphate cement. The adhesive resin cement was slightly, but not significantly, weaker after one week in water. We suggest that excessive loading of restorations cemented with glass ionomer should be avoided for the first two days after the placement. The use of an adhesive resin cement can be recommended on endodontically treated teeth, but further studies are needed to evaluate its biocompatibility and adhesion to dentin.     

玻璃离子水门汀与纳米树脂充填乳牙邻面龋的效果比较

目的 比较玻璃离子水门汀与纳米树脂充填乳牙邻面龋的效果.方法 选择来我科就诊的年龄为5～8岁的乳磨牙邻面龋102例,共320颗患牙,其中深龋组204颗,中、浅龋组116颗,每组随机分为富士Ⅸ玻璃离子水门汀充填(A组)和光固化纳米树脂充填(B组).深龋A组采用氢氧化钙盖髓玻璃离子水门汀充填,深龋B组采用氢氧化钙盖髓,玻璃离子水门汀垫底后纳米树脂充填;中浅龋A组直接玻璃离子水门汀充填,B组中龋玻璃离子水门汀垫底后纳米树脂充填,浅龋直接纳米树脂充填.分别在3个月、6个月、1年时复查充填效果,比较两组成功率.结果 深龋组2种材料在各个时间段成功率均无统计学差异(P＞0.05),中、浅龋组2种材料在3个月时两组成功率无统计学差异(P＞0.05),但在6个月和1年时纳米树脂充填组成功率优于玻璃离子水门汀充填组(P＜0.05).结论 光固化纳米树脂是临床上充填乳牙易脱落之邻面龋较好的选择.     

Two-year evaluation of Class II resin-modified glass ionomer cement/composite open sandwich and composite restorations

Restorations made of a combination of resin modified glass ionomer cement (RMGIC) and composite resin (CR) – open sandwich fillings – have been recommended for use in proximal boxes of molar cavities. The aim of this study was to compare the clinical behaviour over time of RMGIC/CR sandwich restorations versus CR restorations in Class II molar cavities. During a period of 2 years, a total of 220 restorations were placed in 118 patients by one operator (VV). A random block allocation was used to allocate cavities to one of the two restorative techniques. Bitewing radiographs and photographs were taken at baseline and at annual recall appointments. At present, a total of 210 restorations have been evaluated after 1 year and 141 restorations after 2 years. All restorations were evaluated using a modification of USPHS criteria. A total of three RMGIC/CR and two CR restorations (2.8%) were rated as failures caused by endodontic complications or major fractures. Twenty-eight teeth were reported to have postoperative sensitivity at the baseline evaluation 1 week following placement. Nine RMGIC/CR (8.5%) and four CR (4.9%) restorations with minor fractures were rated Charlie but were still acceptable. Bitewing radiographs revealed progression of carious lesions in proximal surfaces of originally intact or restored teeth adjacent to five (5.9%) RMGIC/CR restorations and eight (10.9%) CR restorations. No statistically significant differences between the two types of restoration were observed with respect to marginal adaptation, discoloration and caries progression. However, a higher number of large CR fillings exhibited postoperative sensitivity at baseline compared to moderate CR or extensive and moderate RMGIC/CR restorations. Received: 28. January 2000 / Accepted: 8 May 2000     

A 4- to 6-year retrospective clinical study of cracked teeth restored with bonded indirect resin composite onlays

PURPOSE: The purpose of this study was to retrospectively evaluate the clinical performance of bonded indirect resin composite onlays for the treatment of painful, cracked teeth over a 6-year period. MATERIALS AND METHODS: Forty-three posterior teeth diagnosed as having a crack were selected in the restorative department of the University of Genoa. Inclusion criteria were sensitivity to biting and cold and a clinically visible crack. Direct composite buildup after removal of the existing restoration was performed before definitive cavity preparation. All composite onlay restorations were cemented with an adhesive technique using a 3-step total etch system and a dual-cure composite cement. Patients were interviewed and clinically examined at 1 week, 4 weeks, and every 6 months. RESULTS: The effectiveness of bonded onlay restorations was evaluated for a mean observation time of 4.78 years. At 1 week, 38 (88.37%) restored teeth were free of pain, 3 (6.98%) still had sensitivity to cold, and 2 (4.65%) still had sensitivity to cold and chewing. At 4 weeks, 40 (93.02%) teeth were free of pain, 2 (4.65%) still had sensitivity to cold and chewing, and 1 (2.32%) needed endodontic treatment. Two other teeth (4.65%) also needed endodontic treatment, the first after 2 months and the second after 5 months. During the evaluation period, 3 restorations (6.98%) failed, and upon clinical examination, 40 (93.02%) teeth were free of symptoms with a 6-year survival rate of 93.02% (life table analysis). CONCLUSIONS: Bonded indirect resin composite onlays can be successful in treating painful, cracked teeth. From the findings of this study, it appears that cuspal protection should be incorporated into the design of coronal restorations.     

Prospective observation of a new bioactive luting cement: 2-year follow-up

Purpose: A pilot study was conducted to determine the 2‐year clinical performance of a new bioactive dental cement (Ceramir C&B, formerly XeraCem) for permanent cementation. Materials and Methods: The cement used in this study is a new formulation class, a hybrid material comprising calcium aluminate and glass ionomer. Thirty‐eight crowns and fixed partial denture (FPD) abutments were cemented in 17 patients. Thirty‐one of the abutment teeth were vital, 7 nonvital. Six reconstructions were FPDs comprising 14 abutment teeth (12 vital/2 nonvital). A two‐unit fixed splint was also included. Preparation parameters and cement characteristics (dispensing, working time, seating characteristics, ease of cement removal) were recorded. Baseline and postcementation data were recorded for marginal integrity, marginal discoloration, secondary caries, retention, and gingival inflammation. Tooth sensitivity was assessed at pre‐ and postcementation time points using categorical and visual analogue scale (VAS) assessment measures. Results: Mixing of the cement was reported as “easy.” Clinical working time for this cement was deemed acceptable. Assessment of seating characteristics indicated all restorations were seated completely after cementation. Cement removal was determined to be “easy.” Fifteen of 17 subjects were available for 1‐year recall examination; 13 patients were available for the 2‐year recall examination. Restorations at 2‐year recall examination included 17 single‐unit, full‐coverage crown restorations, four 3‐unit FPDs comprising 8 abutments, and one 2‐unit splint. No retentive failures or sensitivity were recorded at 2‐year recall. Marginal integrities of all restorations/abutments at 2 years were rated in the “alpha” category. Average VAS score for tooth sensitivity decreased from 7.63 mm at baseline to 0.44 mm at 6‐month recall, 0.20 mm at 1‐year recall, and 0.00 mm at 2‐year recall. The average gingival index score for gingival inflammation decreased from 0.56 at baseline to 0.11 at 6‐month recall, then 0.16 at 1‐year recall, and 0.21 at 2‐year recall. Conclusions: Two‐year recall data yielded no loss of retention, no secondary caries, no marginal discolorations, and no subjective sensitivity. All restorations rated “alpha” for marginal integrity at the 2‐year recall. After periodic recalls up to 2 years, the new bioactive cement tested thus far has performed favorably as a luting agent for permanent cementation.     

1-Year clinical study of indirect resin composite restorations luted with a self-adhesive resin cement: effect of enamel etching

In vitro studies have recommended enamel-etching before luting indirect restorations with self-adhesive resin cement. However, there is no scientific proof that this procedure has any clinical relevance. Thus, the aim of this study was to evaluate the effect of enamel-etching on the marginal quality of indirect composite resin restorations (inlay/onlay) using the self-adhesive cement RelyX Unicem clicker. Forty-two posterior teeth were selected from 25 patients that presented one or two teeth with large restorations in need of replacement. All teeth were prepared by the same operator and impressed with polyvinylsiloxane material. The composite resin restorations were built over plaster casts using the incremental technique with a LED device for light-curing the increments. The inlays/onlays were cemented according to one of the following protocols: 1. Etched group (ETR) - selective enamel phosphoric-acid etching + RelyX Unicem clicker; 2. Non-etched group (NER) - RelyX Unicem clicker alone. Each surface was light-cured for 60 s. Recalls occurred after 1 week (baseline), 6 and 12 months when the teeth were evaluated according to previously established scores (modified USPHS criteria). The clinical analysis showed little or no visible changes in the marginal quality after 1 year, even though a probe could detect all the restorations margins. Statistical analysis (Fisher's exact test, p<0.05) detected no differences between the groups after 12 months. No restorations failed and no secondary caries were found. Enamel acid etching had no clinical relevance on the marginal quality of indirect composite resin restorations luted with RelyX Unicem clicker after 1 year of follow up.     

Comparison of microleakage of three acid-base luting cements versus one resin-bonded cement for Class V direct composite inlays

STATEMENT OF PROBLEM: Demineralized dentin beneath set cement may adversely affect microleakage under fixed restorations. PURPOSE: Microleakage of direct composite inlays cemented with acid-base cements and a methyl methacrylate resin cement were evaluated to determine their effect on the integrity of the underlying hybridized dentin. MATERIALS AND METHODS: Sixty Class V box preparations (3 mm x 3 mm x 1.5 mm) were precisely prepared in previously frozen bovine teeth with one margin in enamel and another margin in dentin. Direct composite inlays (EPIC-TMPT) for each preparation were divided into 4 groups of 15 specimens each and cemented with 3 acid-base cements (control group): Elite, Ketac-Cem, Hy-Bond Carbo-Cem, and 1 adhesive resin cement: C&B Metabond. All specimens were stored in distilled water for 24 hours at 37 degrees C before immersion in 0.5% basic fuchsin for 24 hours. The dye penetration was measured on the sectioned specimens at the tooth-cement interface of enamel and cementum margins and recorded with graded criteria under light microscopy (Olympus Vanox-T) at original magnification x 50, 100, and 200. A Kruskal-Wallis and the Mann-Whitney test at P<.05 were used to analyze leakage score. RESULTS: All cementum margins of the 3 acid-base cements tested demonstrated significantly higher leakage scores than cementum margins for inlays cemented with the resin cement tested(P<.01). No leakage along the tooth-cement interface was found for inlays retained with the adhesive resin cement. CONCLUSIONS: Within the limitations of this study, the 3 acid-base cements tested exhibited greater microleakage at the cementum margins than did the adhesive resin cement that was tested.     

Influence of timing of coronal preparation on retention of two types of post cores

PURPOSE: To compare the effect of coronal preparation on retention of cemented cast (Cr-Ni) and IPS post core systems. METHODS: Cr-Ni and IPS post and cores were placed in 48 extracted single rooted human teeth with two different cements (dual-cure resin and glass-ionomer cement) and randomly divided into four groups of 12 specimens each. twelve of each post-core system were cemented with dual-cure cement and the other 12 of each system were cemented with glass-ionomer cement. Twelve specimens of each post core system were subjected to an axially directed removal force using a universal testing machine. Four groups of 12 specimens were divided into subgroups and subjected to preparation of their cores at 15 minutes and 24 hours after cementation. The specimens were tested at 24 hours having been stored in water at 37 degrees C for the waiting period. The forces required for dislodgement of the posts from their prepared spaces were recorded. Data were statistically analyzed using ANOVA and the Newman-Keuls multiple comparison test. RESULTS: Retention generally increased with time following cementation for both groups. The specimens cemented with glass-ionomer cement revealed less retention compared with specimens cemented with resin cement. Preparation of cemented post cores using a high speed handpiece had a significantly negative effect on retention when carried out 15 minutes and 24 hours after cementation.     

36-month clinical evaluation of two adhesives and microhybrid resin composites in Class I restorations

PURPOSE: To compare the clinical performance of a self-etching adhesive with that of a popular etch-and-rinse adhesive in Class I posterior composite restorations. METHODS: 60 Class I resin composite restorations (30 per group) were placed in matched pairs using either the self-etch adhesive Xeno III and the microhybrid resin composite Esthet-X or the etch-and-rinse adhesive OptiBond Solo Plus and Point 4 microhybrid resin composite. Subjects were interviewed via telephone 1 week after restoration placement to assess early post-operative sensitivity. In addition, the restorations were evaluated clinically for post-operative sensitivity, marginal quality, wear, and other characteristics immediately after placement and at 6, 12, 18, and 36 months from baseline. RESULTS: During the first week after placement, subjects reported that 23% of restorations in each group had post-operative sensitivity. Sensitivity decreased greatly with time, and differences between the two groups were never statistically significant. Marginal integrity and discoloration were similar for each group at each recall evaluation. Wear of both resin composites increased over time, but mean wear remained at less than 100 microm for each resin composite at 3 years.