Bind disable attribute dynamically for each row for disabling button row-wise in LWC

[![enter image description here][1]][1]I have a situation in LWC. In a table there are multiple records coming dynamically with selection of available dropdowns. Each row has Approve and Reject button functionality. I have managed Approve and Reject by a custom field. Here after Approval/Rejection I want to disable buttons for selected approved row only.
But because of same disable attribute it disables approve/reject buttons for all unselected rows – that I don't want. I want button disable for only selected row..
Disable attribute in Lightning button for approve/reject is same. disable=(isDisabledButton). How could I achieve this scenario?

HTML CODE

<template for:each={materialMap} for:item="item">
    <tr class="slds-hint-parent" key={item.id}>
        <td class="slds-cell-wrap" scope="col" >
            <div class="slds-truncate slds-cell-wrap">
                {item.materialName__c}
            </div>
        </td>
        <td class="slds-cell-wrap" scope="row">
            <div class="slds-truncate slds-cell-wrap">
                {item.avgCount}
            </div>
        </td>
        <td class="slds-cell-wrap" scope="row">
            <div class="slds-truncate slds-cell-wrap">
                {item.totalValue}
            </div>
        </td>
        <td class="slds-cell-wrap" scope="row">
            <div class="slds-truncate slds-cell-wrap">
                {item.discountedValue}
            </div>
        </td>
        <td if:true={showApproveRejectbutton} class="slds-cell-wrap" scope="row">
            <div class="slds-truncate slds-cell-wrap">
                <lightning-button variant="success" name={item.materialName__c} label="Approve" title="Successful action" onclick={handleApproval} class="slds-m-left_x-small" disabled={isDisabledButton}>
                </lightning-button>
            </div>
        </td>
        <td if:true={showApproveRejectbutton} class="slds-cell-wrap" scope="row">
            <div class="slds-truncate slds-cell-wrap">
                <lightning-button variant="destructive" name={item.materialName__c} label="Reject" title="Destructive action" onclick={handleApproval} class="slds-m-left_x-small" disabled={isDisabledButton}>
                </lightning-button>
            </div>
        </td>
    </tr>
</template>

JS

handleApproval(event){              
    const actionButton = event.target.name;
    let selectedButton= event.currentTarget.name; 
    console.log('selectedButton '+selectedButton);
    let objIndx = this.materialMap.findIndex((item => item.materialName__c== selectedButton));
    console.log('objIndx== '+objIndx);
    let buttonvalue= this.materialMap[objIndx].isDisabledButton=true;
    console.log('Name of buttonvalue  = '+JSON.stringify(buttonvalue));
}

For this

console.log('Name of buttonvalue = '+JSON.stringify(buttonvalue));

I am getting true value but it is not disabling the button