As filed with the Securities and Exchange Commission on July 15, 2020

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

BIOLASE, INC.

(Exact name of registrant as specified in its charter)

4 Cromwell, Irvine, California 92618

(949) 361-1200

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Todd A. Norbe

President and Chief Executive Officer

BIOLASE, Inc.

4 Cromwell

Irvine, California 92618

(949) 361-1200

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copy to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after the effective date of this Registration Statement.

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box.   ☒

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.   ☒ 333-238914

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.   ☐

If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.   ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided to Section 7(a)(2)(B) of the Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

This Registration Statement shall become effective upon filing with the Securities and Exchange Commission in accordance with Rule 462(b) under the Securities Act of 1933.

EXPLANATORY NOTE

This Registration Statement is being filed by Biolase, Inc. (the “Company”) pursuant to Rule 462(b) under the Securities Act of 1933, as amended. Pursuant to Rule 462(b), the Company hereby incorporates by reference into this Registration Statement on Form S-1 in its entirety the Registration Statement on Form S-1 (File No. 333-238914), which was declared effective by the Securities and Exchange Commission (“SEC”) on July 1, 2020 (the “Initial Registration Statement”), including each of the documents filed by the Company with the SEC and incorporated or deemed to be incorporated by reference therein and all exhibits thereto.

In accordance with Rule 462(b) promulgated under the Securities Act, an additional amount of securities having a proposed maximum aggregate offering price of not more than 20% of the maximum aggregate offering price of the securities registered under the Initial Registration Statement are being registered. This Registration Statement is being filed with respect to the registration of an additional $3,000,000 aggregate maximum amount of Units of the Company, each Unit consisting of one share of Series F Convertible Preferred Stock, par value $0.001 per share and 2,500 Warrants, each to purchase one share of Common Stock and an additional $3,000,000 of shares of Common Stock underlying the Warrants, all of which are described in the prospectus constituting a part of the Initial Registration Statement.

The required opinions of counsel and related consent and accountant’s consent are attached hereto and filed herewith.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

All exhibits filed or incorporated by reference in the Registrant’s Registration Statement on Form S-1, as amended (File No. 333-238914), are incorporated by reference into, and shall be deemed to be part of, this Registration Statement, except for the following, which are filed herewith:

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant has duly caused this amendment to be signed on its behalf by the undersigned, thereunto duly authorized in the City of Irvine, State of California, on July 15, 2020.

Pursuant to the requirements of the Securities Act of 1933, this amendment has been signed by the following persons in the capacities and on the dates indicated.