Add and Search Word - Data structure design

Design a data structure that supports the following two operations:

void addWord(word)
bool search(word)

search(word) can search a literal word or a regular expression string containing only letters a-z or .. A . means it can represent any one letter.

Example:

addWord("bad")
addWord("dad")
addWord("mad")
search("pad") -> false
search("bad") -> true
search(".ad") -> true
search("b..") -> true

Note:
You may assume that all words are consist of lowercase letters a-z.

Solution:

class WordDictionary {
    static class TrieNode {
        char c;
        List<TrieNode> children;
        boolean isWord;
        
        public TrieNode(char c) {
            this.c = c;
            children = new ArrayList();
            isWord = false;
        }
    }
    
    TrieNode root;

    /** Initialize your data structure here. */
    public WordDictionary() {
        root = new TrieNode('\0');
    }
    
    /** Adds a word into the data structure. */
    public void addWord(String word) {
        char[] arr = word.toCharArray();
        TrieNode curr = root;
        for (char c : arr) {
            boolean found = false;
            for (TrieNode child : curr.children) {
                if (child.c == c) {
                    curr = child;
                    found = true;
                    break;
                }
            }
            if (!found) {
                TrieNode newNode = new TrieNode(c);
                curr.children.add(newNode);
                curr = newNode;
            }
        }
        curr.isWord = true;
    }
    
    /** Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter. */
    public boolean search(String word) {
        for (TrieNode node : this.root.children) {
            if (search(word, node)) {
                return true;
            }
        }
        return false;
    }
    
    private boolean search(String word, TrieNode root) {
        char c = word.charAt(0);
        TrieNode curr = root;
        if (word.length() == 1) {
            if ((curr.c == c || c == '.') && curr.isWord) return true;
            return false;
        }
        if (c == '.') {
            for (TrieNode child : curr.children) {
                if (search(word.substring(1), child)) {
                    return true;
                }
            }
            return false;
        } else {
           if (c != root.c) {
               return false;
           } else {
                for (TrieNode child : root.children) {
                    if (search(word.substring(1), child)) {
                        return true;
                    }
                }
               return false;
           }
        } 
    }
}

/**
 * Your WordDictionary object will be instantiated and called as such:
 * WordDictionary obj = new WordDictionary();
 * obj.addWord(word);
 * boolean param_2 = obj.search(word);
 */