Clinical Evaluation Of Direct Composite Resin And Indirect Micro Ceramic Composite Resin Restorations In Class-I Cavity Of Permanent Posterior Teeth

Background:Previous studies have indicated that the clinical performance of direct composite restoration mainly depends on the polymerization shrinkage. The use of micro ceramic inlay technique has proved to be elegant approach to overcome the polymerization shrinkage and improve the marginal adaptation, reduce wear and leakage of posterior restorations. Objectives:To compare the clinical performance between direct composite restorations and indirect micro ceramic composite restorations in occlusal surface of permanent posterior teethof class-I cavity. Results: The result of this study showed that there was no statisticallysignificant difference between two groups in the treatment of occlusal surface ofclass-I cavity of permanent posterior teeth (p > 0.05). It was concluded that indirect micro ceramic composite resin shows no better clinical efficacy than that of direct composite resin in occlusal surface of class-I cavity of permanent posterior teeth. Correspondence to: Dr. A H M Zakir Hossain Shikder, Assistant Professor Department of Pedodontics, BSMMU, Cell 02-01552354186 E-mail:zakirendo@gmail.com 1. Assistant Professor, Department of Pedodontics, BSMMU, Dhaka. 2. Assistant Professor, Department of Conservative Dentistry & Endodontics, Dhaka Dental College & Hospital, Dhaka. 3. Assistant Professor, Dept. of Oral Anatomy & Physiology, Bangladesh Dental College. 4. Junior Consultant, Department of Conservative Dentistry & Endodontics, Rangpur Medical College & Hospital. 5. Assistant Professor, Department of Conservative Dentistry & Endodontics, Update Dental College & Hospital, Dhaka. 6. Professor and Chairman, Department of Conservative Dentistry & Endodontics, BSMMU, Dhaka. Introduction: Amalgam is one of the most commonly used direct restorative materials in occlusal surface of class-I cavity of permanent posterior teeth. Amalgam doesn’t bond to tooth structure, contains mercury and it is not aesthetic, but its low cost, easy manipulation, rapid application and good track record of clinical performance, it become a most convenient restorative material in occlusal surface of class-I cavity of permanent posterior teeth. In recent years, the popularity of amalgam has been declined due to public health concerns over its mercury content.1 Now-a-days patients are reluctant to accept any display of metal in their oral cavity due to its unacceptable aesthetics and health hazards. The validity of most of these negative claims is yet to be determined by environmental based study reports. Nevertheless, these ideas have reduced the metallic restoration in dentistry and influenced the greater use of nonmetallic restorations.2 Dental resin composites were introduced initially for use as anterior restorative materials. Later, with technological improvements, the prospect of restoring posterior teeth with composite was introduced. Though there are numerous causes for failure of clinical restorations made of direct composites, the major cause with the earlier posterior composites was poor wear resistance.3While the newest direct composite resin offers excellent optical and mechanical properties, its use in larger posterior restorations International Journal of Human and Health Sciences Vol. 03 No. 02 April’19 Page : 109-115 DOI: http://dx.doi.org/10.31344/ijhhs.v3i2.85 International Journal of Human and Health Sciences Vol. 03 No. 02 April’19 110 is still a challenge since polymerization shrinkage remains a concern in cavities. Though there have been numerous advances in adhesive systems, it is observed that the adhesive interface is unable to resist the polymerization stresses in enamel-free cavity margins.4,5 This leads to improper sealing, which results in microleakage, postoperative sensitivity, and recurrent caries. The achievement of a proper interproximal contact and the complete cure of composite resins in the deepest regions of a cavity are other challenge related to direct composite restorations. Various approaches have been developed to improve some of the deficiencies of direct placement composites.6, 7 However, no method has eliminated the problem of marginal microleakage associated with direct composite.4 Indirect resin composites were introduced to reduce polymerization shrinkage and improve the properties of restorative material. Direct resin composites were composed mostly composed of organic resin matrix, inorganic filler, and coupling agent. The first-generation indirect restorative composites had a composition identical to that of the direct resin. For inlay composites, an additional or secondary cure is given extra orally, which improves the degree of conversion and also reduces the side effects of polymerization shrinkage. It was observed that the first-generation indirect restorative composites showed improved properties only in vitro studies but had failure in clinical studies.8First generation composites showed poor clinical performance. Deficient bonding between organic matrix and inorganic fillers was the main problem leading to unsatisfactory wear resistance, high incidence of bulk fracture, marginal gap, microleakage, and adhesive failure in the first attempts to restore posterior teeth. Measures to solve these problems included increasing of inorganic filler content, reduction of filler size, and modification of the polymerization system. The second-generation composites have micro hybrid filler. By increasing the filler load, mechanical properties and wear resistance is improved, and by reducing the organic resin matrix, the polymerization shrinkage is reduced.9 The new composite resins contain high amounts of filler contents, which make them adequate for restoring posterior teeth. Ceramage is a micro ceramic polymer system with 73% of zirconium silicate filler (PFS-Progressive Fine Structured filler) supported by an organic polymer matrix which ensures a durable surface quality with excellent polishability and high resistance to plaque. This extra ordinary structure of ceramage shows properties similar to porcelain making it an ideal choice for posterior restorations. The aim of this study is to compare the clinical performance of direct composite resin restoration and indirect micro ceramic composite resin restorations at 3, 6, 9, and 12 months, using the modified USPHS criteria as the main evaluation. Materials and Methods: This was an experimental clinical trialof one year. Study was performed at the Department of Conservative Dentistry and Endodontics, Faculty of dentistry, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Patient attending the outdoor patient Department of Conservative Dentistry and Endodontics, BSMMU was included in the study. Simple random sampling (Lottery method) was used to allocate the samples. Thirty-six teeth that fulfilled the inclusion criteria were selected for the study from outpatient Department of Conservative Dentistry and Endodontics. These samples were randomly assigned to two groups; Group 1 (Direct composite restorations) and Group 2 (Indirect micro ceramic composite restorations). Restoration was assessed bymodified Ryge’s criteria by means of color matching, marginal adaptation, and secondary caries. Patients were recalled after 3, 6, 9, and 12 months for follow up visit to evaluate the colour match, marginal adaptation and secondary caries. Chi-square test was used for testing differences between the two groups. Results: The study was conducted with 18 patients with 36 restorations could be evaluated. The restorations were evaluated for color matching (stability of color), marginal adaptation and secondary caries. Using Chi-square test, no statistically significance differences among the restorative materials were shown all the evaluation criteria. The result of the clinical evaluation of the 36 restorations using modified USPHS criteria are summarized in tables I, II &III TableI shows comparison of color matching (stability of color) between direct and indirect micro ceramic composite restoration during follow up period. It was observed that at the evaluation period the difference was not statistically significant (p > 0.05) between two groups.


Introduction:
Amalgam is one of the most commonly used direct restorative materials in occlusal surface of class-I cavity of permanent posterior teeth.Amalgam doesn't bond to tooth structure, contains mercury and it is not aesthetic, but its low cost, easy manipulation, rapid application and good track record of clinical performance, it become a most convenient restorative material in occlusal surface of class-I cavity of permanent posterior teeth.In recent years, the popularity of amalgam has been declined due to public health concerns over its mercury content. 1 Now-a-days patients are reluctant to accept any display of metal in their oral cavity due to its unacceptable aesthetics and health hazards.The validity of most of these negative claims is yet to be determined by environmental based study reports.Nevertheless, these ideas have reduced the metallic restoration in dentistry and influenced the greater use of nonmetallic restorations. 2ental resin composites were introduced initially for use as anterior restorative materials.Later, with technological improvements, the prospect of restoring posterior teeth with composite was introduced.Though there are numerous causes for failure of clinical restorations made of direct composites, the major cause with the earlier posterior composites was poor wear resistance. 3While the newest direct composite resin offers excellent optical and mechanical properties, its use in larger posterior restorations is still a challenge since polymerization shrinkage remains a concern in cavities.Though there have been numerous advances in adhesive systems, it is observed that the adhesive interface is unable to resist the polymerization stresses in enamel-free cavity margins. 4,5This leads to improper sealing, which results in microleakage, postoperative sensitivity, and recurrent caries.The achievement of a proper interproximal contact and the complete cure of composite resins in the deepest regions of a cavity are other challenge related to direct composite restorations.Various approaches have been developed to improve some of the deficiencies of direct placement composites. 6,7 wever, no method has eliminated the problem of marginal microleakage associated with direct composite. 4ndirect resin composites were introduced to reduce polymerization shrinkage and improve the properties of restorative material.Direct resin composites were composed mostly composed of organic resin matrix, inorganic filler, and coupling agent.The first-generation indirect restorative composites had a composition identical to that of the direct resin.For inlay composites, an additional or secondary cure is given extra orally, which improves the degree of conversion and also reduces the side effects of polymerization shrinkage.It was observed that the first-generation indirect restorative composites showed improved properties only in vitro studies but had failure in clinical studies. 8First generation composites showed poor clinical performance.Deficient bonding between organic matrix and inorganic fillers was the main problem leading to unsatisfactory wear resistance, high incidence of bulk fracture, marginal gap, microleakage, and adhesive failure in the first attempts to restore posterior teeth.Measures to solve these problems included increasing of inorganic filler content, reduction of filler size, and modification of the polymerization system.The second-generation composites have micro hybrid filler.By increasing the filler load, mechanical properties and wear resistance is improved, and by reducing the organic resin matrix, the polymerization shrinkage is reduced. 9The new composite resins contain high amounts of filler contents, which make them adequate for restoring posterior teeth.Ceramage is a micro ceramic polymer system with 73% of zirconium silicate filler (PFS-Progressive Fine Structured filler) supported by an organic polymer matrix which ensures a durable surface quality with excellent polishability and high resistance to plaque.This extra ordinary structure of ceramage shows properties similar to porcelain making it an ideal choice for posterior restorations.
The aim of this study is to compare the clinical performance of direct composite resin restoration and indirect micro ceramic composite resin restorations at 3, 6, 9, and 12 months, using the modified USPHS criteria as the main evaluation.

Materials and Methods:
This Chi-square test was used for testing differences between the two groups.

Results:
The study was conducted with 18 patients with 36 restorations could be evaluated.The restorations were evaluated for color matching (stability of color), marginal adaptation and secondary caries.
Using Chi-square test, no statistically significance differences among the restorative materials were shown all the evaluation criteria.The result of the clinical evaluation of the 36 restorations using modified USPHS criteria are summarized in tables I, II &III TableI shows comparison of color matching (stability of color) between direct and indirect micro ceramic composite restoration during follow up period.It was observed that at the evaluation period the difference was not statistically significant (p > 0.05) between two groups.Tableshows comparison of secondary caries between direct and indirect micro ceramic composite restoration during follow up period.
It was observed that at the evaluation period the difference was not statistically significant (p > 0.05) between two groups.At the time of evaluation period, there was no secondary caries in either direct or indirect composite resin restoration was found (Table III).

Discussion
In this present study when direct restorations were examined at 3 and 6 months, it was found that all direct and indirect restorations showed acceptable color matching and marginal adaptation.Furthermore, neither secondary caries nor any post-operative sensitivity or discoloration of restoration was observed.The differences between two groups were not statistically significant.However, at nine months, two direct and one indirect composite (ceramage) restorations showed loss of marginal adaptation due to chipping at margin of the restoration and they were not replaced.A careful examination of these restorations revealed that all chipping occurred due to direct contact with opposing cusp.The problems highlighted here could have been avoided by the operator.Direct and indirect composite restorations (ceramage) should not be placed in direct contact with opposing cusp.This is also supported by some of the previous studies. 10hen the color of the restorations was verified, it was found that 3 (16.7%)direct and 2 indirect (11.1%) restorations were slightly mismatched with the adjacent teeth.Careful examinations of the restorations showed that mismatch of the colors of the restorations were due to body discoloration of the materials.Previous studies have reported that mismatch of the composite restoration could be happen due to gradual discoloration of the monomer component of the material.The results found in that present study were correspondent to previous study of Ali Riza Cetin and Nimet UNLU. 11This study compared direct and indirect composite restoration in posterior teeth and found that all the restoration demonstrated clinically satisfactory performance with no significance differences among them.At 12 months observation period, the results of marginal adaptation did not changed.Again, 2 direct and 1 indirect restorations showed loss of marginal adaptation.At this stage, these restorations were not replaced but they were repaired by composite resin.Furthermore, 4 (22.2%)direct and 2 (11.1%) indirect restorations showed slight mismatch with the adjacent teeth.Again, the reason was due to body discoloration.Furthermore, no restorations showed secondary caries at this observation period.The results between two groups were not statistically significant.
Aesthetic dentistry continues to evolve through innovations in restorative material and conservative preparation technique.The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses.Indirect composites offer an esthetic alternative to micro ceramic composite for posterior teeth.Many evaluation criteria are available for evaluation of clinical study.United States Public Health (USPHS) criteria were used for the clinical evaluation of toothcolored restorations in posterior teeth, which is originally based on Ryge criteria. 12In this study, direct composite restorations and indirect micro ceramic composite (ceramage) restorations were assessed to ensure comparability of the results using USPHS criteria.
In the present one-year clinical studyboth the direct and indirect composite restorations were rated as clinically acceptable according to the evaluation criteria used and that there were no statistically significant differences in performance among the tested materials.On the lack of statistically significant differences, it could be due to the multiple similarities-in terms of chemical composition and high filler content underlying the composites used in this study.However, differences might emerge over longer periods of use.Nevertheless, better clinical performance might be obtained using ceramage, since they are indirect composite resins specifically designed for restoring posterior teeth.Furthermore, it is claimed that indirect composite, when tempered with heat and light, could have an enhanced degree of cure, thereby leading to improved physical properties.
According to a previous study, it was found that indirect ceramic inlays reveal better clinical results than direct composite restorations (IvoclarVivadent'sHeliomolar) in terms of marginal adaptation, color matching and secondary caries.
The results of this present study showed that there were no statistically significant differences between direct and indirect restorations in respect of marginal adaptation, color matching and secondary caries.So, this study will help the clinician that indirect micro ceramic composite resin shows no better clinical efficacy than that of direct composite resin in occlusal surface of class-I cavity of permanentposterior teeth.
All patients strictly followed the instructions during the course of treatment.This study had controlled the confounders which were induced by the participants.So, these study findings are unlikely to be influenced by other confounding variables.

Conclusion:
It can be concluded that indirect micro ceramic composite resin shows no better clinical efficacy than that of direct composite resin in occlusal surface of class-I cavity of permanent posterior teeth.
was an experimental clinical trialof one year.Study was performed at the Department of Conservative Dentistry and Endodontics, Faculty of dentistry, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh.
Patient attending the outdoor patient Department of Conservative Dentistry and Endodontics, BSMMU was included in the study.Simple random sampling (Lottery method) was used to allocate the samples.Thirty-six teeth that fulfilled the inclusion criteria were selected for the study from outpatient Department of Conservative Dentistry and Endodontics.These samples were randomly assigned to two groups; Group 1 (Direct composite restorations) and Group 2 (Indirect micro ceramic composite restorations).Restoration was assessed bymodified Ryge's criteria by means of color matching, marginal adaptation, and secondary caries.Patients were recalled after 3, 6, 9, and 12 months for follow up visit to evaluate the colour match, marginal adaptation and secondary caries.

Table I : Comparison of color matching between two groups (n=18 teeth)
n = Number of samples a = No statistics are computed because of identical numbers in both groups ns = Not Statistically Significant Group1: Direct composite restoration Group2: Indirect micro ceramic composite restoration (ceramage) TableII: Comparison of marginal adaptation between two groups (n=18 teeth)

Table III : Comparison of secondary caries between two groups (n=18 teeth)
= Number of samples a = No statistics are computed because of identical numbers in both groups ns = Not Statistically Significant Group1: Direct composite restoration Group2: Indirect micro ceramic composite restoration (ceramage)